Environmental Science › Ecology

Wildlife Ecology and Conservation

Works Count: 125741

Wikipedia

Description

This cluster of papers covers a wide range of topics in wildlife ecology and conservation biology, including estimating occupancy rates, analyzing animal movement patterns, trophic cascades, habitat selection, population dynamics of large herbivores and carnivores, human-wildlife conflict, camera trapping for wildlife monitoring, and strategies for conservation management. It also explores the impact of predation risk on prey species, global biodiversity loss, and the ecological implications of human-induced stress on animal behavior.

Keywords

Occupancy Rates; Animal Movement; Trophic Cascades; Habitat Selection; Population Dynamics; Human-Wildlife Conflict; Camera Trapping; Conservation Management; Predation Risk; Global Biodiversity Loss

Invasive species in a changing world

2001-04-01

Harold A. Mooney , Richard J. Hobbs

Here, the authors set out strategies for dealing with the problem of non-indigenous species entering into habitats because of the breakdown of long-established biogeographic barriers. This is just one of … Here, the authors set out strategies for dealing with the problem of non-indigenous species entering into habitats because of the breakdown of long-established biogeographic barriers. This is just one of the unfavourable aspects of globalised commerce.

Handbook of ethological methods

1997-04-01

Philip N. Lehner

Preface 1. Introduction Part I. Getting Started: 2. A conceptual model of animal behavior 3. Choice of subject 4. Reconnaissance observation 5. Delineation of research 6. Design of research 7. … Preface 1. Introduction Part I. Getting Started: 2. A conceptual model of animal behavior 3. Choice of subject 4. Reconnaissance observation 5. Delineation of research 6. Design of research 7. Experimental research Part II. Collecting the Data: 8. Data collection methods 9. Data collection equipment 10. Selected examples of data collection and description Part III. Analysing the Results: 11. Introduction to statistical methods 12. Selecting a statistical test 13. Parametric statistical tests 14. Nonparametric statistical tests 15. Rates of behavior and analysis of sequences 16. Statistical analyses for spatial orientation, time and spatial patterns 17. Presentation and interpretation of results Bibliography Appendices: A. Statistical figures and tables B. Microcomputers: an overview for ethologists by James Ha C. Guidelines for the use of animals in research D. Ethics in animal behavior research Index.

The Structure and Dynamics of Geographic Ranges

2003-05-01

Kevin J. Gaston

Abstract No species occurs everywhere. Indeed, the majority are absent from most places, and where they do occur they are usually quite rare. Gaston discusses the structure of these distributions … Abstract No species occurs everywhere. Indeed, the majority are absent from most places, and where they do occur they are usually quite rare. Gaston discusses the structure of these distributions - the structure of the geographic ranges of species. Gaston is particularly concerned with the factors that determine the limits to a species’ geographic range, how the sizes of those ranges vary, and patterns in that variation. Also considered are the distribution of individuals amongst those sites where a species does occur and what determines that distribution, and some of the practical implications of all these. Both in a pure and applied context, ecologists need a broader perspective on their subject matter than has historically prevailed. This book provides one such perspective. A must have book for any researchers and graduate students studying macroecology, biogeography and conservation biology.

Mesopredator release and avifaunal extinctions in a fragmented system

1999-08-01

Kevin R. Crooks , Michael E. Soulé

unmarked: AnRPackage for Fitting Hierarchical Models of Wildlife Occurrence and Abundance

2011-01-01

Ian Fiske , Richard B. Chandler

Ecological research uses data collection techniques that are prone to substantial and unique types of measurement error to address scientific questions about species abundance and distribution. These data collection schemes … Ecological research uses data collection techniques that are prone to substantial and unique types of measurement error to address scientific questions about species abundance and distribution. These data collection schemes include a number of survey methods in which unmarked individuals are counted, or determined to be present, at spatially- referenced sites. Examples include site occupancy sampling, repeated counts, distance sampling, removal sampling, and double observer sampling. To appropriately analyze these data, hierarchical models have been developed to separately model explanatory variables of both a latent abundance or occurrence process and a conditional detection process. Because these models have a straightforward interpretation paralleling mechanisms under which the data arose, they have recently gained immense popularity. The common hierarchical structure of these models is well-suited for a unified modeling interface. The R package unmarked provides such a unified modeling framework, including tools for data exploration, model fitting, model criticism, post-hoc analysis, and model comparison.

Explicit estimates from capture-recapture data with both death and immigration-stochastic model

1965-06-01

G. M. Jolly

A brief review, with references, of the literature on capture-recapture theory is given in Jolly (1963). More recently, Cormack (1964) gives a solution, including asymptotic variances, for a specific situation … A brief review, with references, of the literature on capture-recapture theory is given in Jolly (1963). More recently, Cormack (1964) gives a solution, including asymptotic variances, for a specific situation involving the marking and release of a non-random sample of fulmar petrels. His model is stochastic and will be referred to in ? 4. Seber (1962, 1965) has also produced some interesting solutions, and these together with Darroch (1958, 1959) are most directly relevant to our present problem. Darroch (1958, 1959) shows that in a fully stochastic model with either immigration (often called dilution) or death (or emigration), the population parameters can be easily estimated by maximum likelihood. For the more general case when death and immigration are operating simultaneously he derives estimation equations by equating certain observations to their expectations, but does not give variances or covariances for the estimates. In a later paper, (Darroch, 1961), he considers estimation for a closed population consisting of different strata. Seber (1962) establishes a stochastic model for what he calls the multi-sample single recapture census in which an individual cannot be recaptured more than once. This situation arises, for example, when the recaptures are made in the course of hunting or fishing. He allows for both death and immigration in the population, provides explicit maximumlikelihood estimates of the parameters with variances, and suggests tests for certain of the assumptions. In a second paper, (Seber, 1965), he considers a multiple-recapture model differing only slightly from that of Darroch (1959), with both death and immigration. Again, he provides explicit maximum-likelihood estimates of the parameters with variances. A test is also given for equi-catchability in a closed population of individuals with different capture histories. The first purpose of the present paper is to derive a general probability distribution designed to fit the majority of capture-recapture problems involving a 'single' population. The word 'single' here denotes a population covering an area within whose boundaries the animals (or, in general, individuals or members) are free to move and to mix with others of their kind, but which is regarded as a single area in respect of which parameters are to be estimated. The type of situation which is thus excluded by this definition is one where the population is split into a number of defined areas, and separate population estimates are required for each area as well as for numbers of animals moving from one area to another. The single population, however, need not be homogeneous but may consist of different classes of animals behaving in different ways. The other assumptions underlying the model are stated with the notation in ? 2, and the generalized probability distribution is derived in ?3.

Uninformative Parameters and Model Selection Using Akaike's Information Criterion

2010-08-01

Todd W. Arnold

Abstract: As use of Akaike's Information Criterion (AIC) for model selection has become increasingly common, so has a mistake involving interpretation of models that are within 2 AIC units (ΔAIC … Abstract: As use of Akaike's Information Criterion (AIC) for model selection has become increasingly common, so has a mistake involving interpretation of models that are within 2 AIC units (ΔAIC ≤ 2) of the top‐supported model. Such models are <2 ΔAIC units because the penalty for one additional parameter is +2 AIC units, but model deviance is not reduced by an amount sufficient to overcome the 2‐unit penalty and, hence, the additional parameter provides no net reduction in AIC. Simply put, the uninformative parameter does not explain enough variation to justify its inclusion in the model and it should not be interpreted as having any ecological effect. Models with uninformative parameters are frequently presented as being competitive in the Journal of Wildlife Management , including 72% of all AIC‐based papers in 2008, and authors and readers need to be more aware of this problem and take appropriate steps to eliminate misinterpretation. I reviewed 5 potential solutions to this problem: 1) report all models but ignore or dismiss those with uninformative parameters, 2) use model averaging to ameliorate the effect of uninformative parameters, 3) use 95% confidence intervals to identify uninformative parameters, 4) perform all‐possible subsets regression and use weight‐of‐evidence approaches to discriminate useful from uninformative parameters, or 5) adopt a methodological approach that allows models containing uninformative parameters to be culled from reported model sets. The first approach is preferable for small sets of a priori models, whereas the last 2 approaches should be used for large model sets or exploratory modeling.

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Statistical confidence for likelihood‐based paternity inference in natural populations

1998-05-01

Tristan Marshall , Jon Slate , Loeske E. B. Kruuk +1 more

Paternity inference using highly polymorphic codominant markers is becoming common in the study of natural populations. However, multiple males are often found to be genetically compatible with each offspring tested, … Paternity inference using highly polymorphic codominant markers is becoming common in the study of natural populations. However, multiple males are often found to be genetically compatible with each offspring tested, even when the probability of excluding an unrelated male is high. While various methods exist for evaluating the likelihood of paternity of each nonexcluded male, interpreting these likelihoods has hitherto been difficult, and no method takes account of the incomplete sampling and error‐prone genetic data typical of large‐scale studies of natural systems. We derive likelihood ratios for paternity inference with codominant markers taking account of typing error, and define a statistic Δ for resolving paternity. Using allele frequencies from the study population in question, a simulation program generates criteria for Δ that permit assignment of paternity to the most likely male with a known level of statistical confidence. The simulation takes account of the number of candidate males, the proportion of males that are sampled and gaps and errors in genetic data. We explore the potentially confounding effect of relatives and show that the method is robust to their presence under commonly encountered conditions. The method is demonstrated using genetic data from the intensively studied red deer ( Cervus elaphus ) population on the island of Rum, Scotland. The Windows‐based computer program, CERVUS , described in this study is available from the authors. CERVUS can be used to calculate allele frequencies, run simulations and perform parentage analysis using data from all types of codominant markers.

Territoriality and Home Range Concepts as Applied to Mammals

1943-08-01

W. H. Burt

Journal Article Territoriality and Home Range Concepts as Applied to Mammals Get access William Henry Burt William Henry Burt Museum Of Zoology, Ann Arbor, Michigan Search for other works by … Journal Article Territoriality and Home Range Concepts as Applied to Mammals Get access William Henry Burt William Henry Burt Museum Of Zoology, Ann Arbor, Michigan Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 24, Issue 3, 17 August 1943, Pages 346–352, https://doi.org/10.2307/1374834 Published: 17 August 1943

Review Lecture: Mammalian mating systems

1989-05-22

Tom Clutton-Brock

Male mammals show a diverse array of mating bonds, including obligate monogamy, unimale and group polygyny and promiscuity. These are associated with a wide variety of different forms of mate … Male mammals show a diverse array of mating bonds, including obligate monogamy, unimale and group polygyny and promiscuity. These are associated with a wide variety of different forms of mate guarding, including the defence of feeding and mating territories, the defence of female groups and the defence of individual receptive females. Female mating bonds include long-term monogamy, serial monogamy, polyandry and promiscuity. Both male and female mating behaviour varies widely within species. Variation in male mating behaviour is related to the effect of male assistance in rearing young and to the defensibility of females by males. The latter is, in turn, related to female ranging behaviour and to the size and stability of female groups. Much of the variation in mammalian mating bonds and systems of mate guarding can be attributed to differences in these three variables.

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Edge Effects and the Extinction of Populations Inside Protected Areas

1998-06-26

Roșie Woodroffe , Joshua R. Ginsberg

Theory predicts that small populations may be driven to extinction by random fluctuations in demography and loss of genetic diversity through drift. However, population size is a poor predictor of … Theory predicts that small populations may be driven to extinction by random fluctuations in demography and loss of genetic diversity through drift. However, population size is a poor predictor of extinction in large carnivores inhabiting protected areas. Conflict with people on reserve borders is the major cause of mortality in such populations, so that border areas represent population sinks. The species most likely to disappear from small reserves are those that range widely-and are therefore most exposed to threats on reserve borders-irrespective of population size. Conservation efforts that combat only stochastic processes are therefore unlikely to avert extinction.

Does organic farming benefit biodiversity?

2004-09-21

David Hole , Allan J. Perkins , Jeremy D. Wilson +3 more

Analysis of Ecological Communities

2003-04-23

Marti J. Anderson

Ecosystem Decay of Amazonian Forest Fragments: a 22‐Year Investigation

2002-05-28

William F. Laurance , Thomas Ε. Lovejoy , Heraldo L. Vasconcelos +7 more

Abstract: We synthesized key findings from the Biological Dynamics of Forest Fragments Project, the world's largest and longest‐running experimental study of habitat fragmentation. Although initially designed to assess the influence … Abstract: We synthesized key findings from the Biological Dynamics of Forest Fragments Project, the world's largest and longest‐running experimental study of habitat fragmentation. Although initially designed to assess the influence of fragment area on Amazonian biotas, the project has yielded insights that go far beyond the original scope of the study. Results suggest that edge effects play a key role in fragment dynamics, that the matrix has a major influence on fragment connectivity and functioning, and that many Amazonian species avoid even small (<100‐m–wide) clearings. The effects of fragmentation are highly eclectic, altering species richness and abundances, species invasions, forest dynamics, the trophic structure of communities, and a variety of ecological and ecosystem processes. Moreover, forest fragmentation appears to interact synergistically with ecological changes such as hunting, fires, and logging, collectively posing an even greater threat to the rainforest biota.

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Status and Ecological Effects of the World’s Largest Carnivores

2014-01-09

William J. Ripple , James A. Estes , Robert L. Beschta +7 more

Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and … Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth's largest carnivores and all that depends upon them, including humans.

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Modeling Survival and Testing Biological Hypotheses Using Marked Animals: A Unified Approach with Case Studies

1992-03-01

Jean‐Dominique Lebreton , Kenneth P. Burnham , Jean Clobert +1 more

The understanding of the dynamics of animal populations and of related ecological and evolutionary issues frequently depends on a direct analysis of life history parameters. For instance, examination of trade—offs … The understanding of the dynamics of animal populations and of related ecological and evolutionary issues frequently depends on a direct analysis of life history parameters. For instance, examination of trade—offs between reproduction and survival usually rely on individually marked animals, for which the exact time of death is most often unknown, because marked individuals cannot be followed closely through time. Thus, the quantitative analysis of survival studies and experiments must be based on capture—recapture (or resighting) models which consider, besides the parameters of primary interest, recapture or resighting rates that are nuisance parameters. Capture—recapture models oriented to estimation of survival rates are the result of a recent change in emphasis from earlier approaches in which population size was the most important parameter, survival rates having been first introduced as nuisance parameters. This emphasis on survival rates in capture—recapture models developed rapidly in the 1980s and used as a basic structure the Cormack—Jolly—Seber survival model applied to an homogeneous group of animals, with various kinds of constraints on the model parameters. These approaches are conditional on first captures; hence they do not attempt to model the initial capture of unmarked animals as functions of population abundance in addition to survival and capture probabilities. This paper synthesizes, using a common framework, these recent developments together with new ones, with an emphasis on flexibility in modeling, model selection, and the analysis of multiple data sets. The effects on survival and capture rates of time, age, and categorical variables characterizing the individuals (e.g., sex) can be considered, as well as interactions between such effects. This "analysis of variance" philosophy emphasizes the structure of the survival and capture process rather than the technical characteristics of any particular model. The flexible array of models encompassed in this synthesis uses a common notation. As a result of the great level of flexibility and relevance achieved, the focus is changed from fitting a particular model to model building and model selection. The following procedure is recommended: (1) start from a global model compatible with the biology of the species studied and with the design of the study, and assess its fit; (2) select a more parsimonious model using Akaike's Information Criterion to limit the number of formal tests; (3) test for the most important biological questions by comparing this model with neighboring ones using likelihood ratio tests; and (4) obtain maximum likelihood estimates of model parameters with estimates of precision. Computer software is critical, as few of the models now available have parameter estimators that are in closed form. A comprehensive table of existing computer software is provided. We used RELEASE for data summary and goodness—of—fit tests and SURGE for iterative model fitting and the computation of likelihood ratio tests. Five increasingly complex examples are given to illustrate the theory. The first, using two data sets on the European Dipper (Cinclus cinclus), tests for sex—specific parameters, explores a model with time—dependent survival rates, and finally uses a priori information to model survival allowing for an environmental variable. The second uses data on two colonies of the Swift (Apus apus), and shows how interaction terms can be modeled and assessed and how survival and recapture rates sometimes partly counterbalance each other. The third shows complex variation in survival rates across sexes and age classes in the roe deer (Capreolus capreolus), with a test of density dependence in annual survival rates. The fourth is an example of experimental density manipulation using the common lizard (Lacerta vivipara). The last example attempts to examine a large and complex data set on the Greater Flamingo (Phoenicopterus ruber), where parameters are age specific, survival is a function of an environmental variable, and an age × year interaction term is important. Heterogeneity seems present in this example and cannot be adequately modeled with existing theory. The discussion presents a summary of the paradigm we recommend and details issues in model selection and design, and foreseeable future developments.

Predicting extinction risk in declining species

2000-10-07

Andy Purvis , John L. Gittleman , Guy Cowlishaw +1 more

What biological attributes predispose species to the risk of extinction? There are many hypotheses but so far there has been no systematic analysis for discriminating between them. Using complete phylogenies … What biological attributes predispose species to the risk of extinction? There are many hypotheses but so far there has been no systematic analysis for discriminating between them. Using complete phylogenies of contemporary carnivores and primates, we present, to our knowledge, the first comparative test showing that high trophic level, low population density slow life history and, in particular, small geographical range size are all significantly and independently associated with a high extinction risk in declining species. These traits together explain nearly 50% of the total between-species variation in extinction risk. Much of the remaining variation can be accounted for by external anthropogenic factors that affect species irrespective of their biology.

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Compositional Analysis of Habitat Use From Animal Radio‐Tracking Data

1993-07-01

Nicholas J. Aebischer , Peter Robertson , Robert Kenward

Analysis of habitat use based on radio—tagged animals presents difficulties inadequately addressed by current methods. Areas of concern are sampling level, data pooling across individuals, non—independence of habitat proportions, differential … Analysis of habitat use based on radio—tagged animals presents difficulties inadequately addressed by current methods. Areas of concern are sampling level, data pooling across individuals, non—independence of habitat proportions, differential habitat use by groups of animals, and arbitrary definition of habitat availability. We advocate proportional habitat use by individual animals as a basis for analysis. Hypothesis testing of such nonstandard multivariate data is done by compositional analysis, which encompasses all MANOVA/MANCOVA—type linear models. The applications to habitat use range from testing for age class effects or seasonal differences, to examining relationships with food abundance or home range size. We take as an example the comparison of habitat use and availability. The concepts are explained and demonstrated on two data sets, illustrating different methods of treating missing values. We compare utilized with available habitats in two stages, examining home range selection within the overall study area first, then habitat use within the home range. At each stage, assuming that use differs from random, habitats can be ranked according to relative use, and significant between—rank differences located. Compositional analysis is also suited to the analysis of time budgets or diets.

The package “adehabitat” for the R software: A tool for the analysis of space and habitat use by animals

2006-04-19

Clément Calenge

Red Deer. Behavior and Ecology of Two Sexes

1983-10-01

Adam Watson , Tim Clutton‐Brock , F. E. Guinness +1 more

Red Deer: Behavior and Ecology of Two Sexes is the most extensive study yet available of reproduction in wild vertebrate. The authors synthesize data collected over ten years on a … Red Deer: Behavior and Ecology of Two Sexes is the most extensive study yet available of reproduction in wild vertebrate. The authors synthesize data collected over ten years on a population of individually recognizable red deer, usually regarded as conspecific with the American elk. Their results reveal the extent of sex differences in behavior, reproduction, and ecology and make a substantial contribution to our understanding of sexual selection.

Human‐Carnivore Conflict and Perspectives on Carnivore Management Worldwide

2003-12-01

Adrian Treves , K. Ullas Karanth

Abstract: Carnivore conservation depends on the sociopolitical landscape as much as the biological landscape. Changing political attitudes and views of nature have shifted the goals of carnivore management from those … Abstract: Carnivore conservation depends on the sociopolitical landscape as much as the biological landscape. Changing political attitudes and views of nature have shifted the goals of carnivore management from those based on fear and narrow economic interests to those based on a better understanding of ecosystem function and adaptive management. In parallel, aesthetic and scientific arguments against lethal control techniques are encouraging the development of nonlethal approaches to carnivore management. We anticipate greater success in modifying the manner and frequency with which the activities of humans and domestic animals intersect with those of carnivores. Success should permit carnivore populations to persist for decades despite human population growth and modification of habitat.

Inference of Population Splits and Mixtures from Genome-Wide Allele Frequency Data

2012-11-15

Joseph K. Pickrell , Jonathan K. Pritchard

Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, … Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, we present a statistical model for inferring the patterns of population splits and mixtures in multiple populations. In our model, the sampled populations in a species are related to their common ancestor through a graph of ancestral populations. Using genome-wide allele frequency data and a Gaussian approximation to genetic drift, we infer the structure of this graph. We applied this method to a set of 55 human populations and a set of 82 dog breeds and wild canids. In both species, we show that a simple bifurcating tree does not fully describe the data; in contrast, we infer many migration events. While some of the migration events that we find have been detected previously, many have not. For example, in the human data, we infer that Cambodians trace approximately 16% of their ancestry to a population ancestral to other extant East Asian populations. In the dog data, we infer that both the boxer and basenji trace a considerable fraction of their ancestry (9% and 25%, respectively) to wolves subsequent to domestication and that East Asian toy breeds (the Shih Tzu and the Pekingese) result from admixture between modern toy breeds and "ancient" Asian breeds. Software implementing the model described here, called TreeMix, is available at http://treemix.googlecode.com.

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Urbanization as a major cause of biotic homogenization

2005-11-03

Michael L. McKinney

The Impact of Conservation on the Status of the World’s Vertebrates

2010-10-27

Michael Hoffmann , Craig Hilton‐Taylor , Ariadne Angulo +7 more

Assessing Biodiversity Declines Understanding human impact on biodiversity depends on sound quantitative projection. Pereira et al. (p. 1496 , published online 26 October) review quantitative scenarios that have been developed … Assessing Biodiversity Declines Understanding human impact on biodiversity depends on sound quantitative projection. Pereira et al. (p. 1496 , published online 26 October) review quantitative scenarios that have been developed for four main areas of concern: species extinctions, species abundances and community structure, habitat loss and degradation, and shifts in the distribution of species and biomes. Declines in biodiversity are projected for the whole of the 21st century in all scenarios, but with a wide range of variation. Hoffmann et al. (p. 1503 , published online 26 October) draw on the results of five decades' worth of data collection, managed by the International Union for Conservation of Nature Species Survival Commission. A comprehensive synthesis of the conservation status of the world's vertebrates, based on an analysis of 25,780 species (approximately half of total vertebrate diversity), is presented: Approximately 20% of all vertebrate species are at risk of extinction in the wild, and 11% of threatened birds and 17% of threatened mammals have moved closer to extinction over time. Despite these trends, overall declines would have been significantly worse in the absence of conservation actions.

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The Natal and Breeding Dispersal of Birds

1982-11-01

P. J. Greenwood , Paul Harvey

Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict … Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes, ...Read More

Causes and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamics

2005-04-18

Diana E. Bowler , Tim G. Benton

Knowledge of the ecological and evolutionary causes of dispersal can be crucial in understanding the behaviour of spatially structured populations, and predicting how species respond to environmental change. Despite the … Knowledge of the ecological and evolutionary causes of dispersal can be crucial in understanding the behaviour of spatially structured populations, and predicting how species respond to environmental change. Despite the focus of much theoretical research, simplistic assumptions regarding the dispersal process are still made. Dispersal is usually regarded as an unconditional process although in many cases fitness gains of dispersal are dependent on environmental factors and individual state. Condition-dependent dispersal strategies will often be superior to unconditional, fixed strategies. In addition, dispersal is often collapsed into a single parameter, despite it being a process composed of three interdependent stages: emigration, inter-patch movement and immigration, each of which may display different condition dependencies. Empirical studies have investigated correlates of these stages, emigration in particular, providing evidence for the prevalence of conditional dispersal strategies. Ill-defined use of the term 'dispersal', for movement across many different spatial scales, further hinders making general conclusions and relating movement correlates to consequences at the population level. Logistical difficulties preclude a detailed study of dispersal for many species, however incorporating unrealistic dispersal assumptions in spatial population models may yield inaccurate and costly predictions. Further studies are necessary to explore the importance of incorporating specific condition-dependent dispersal strategies for evolutionary and population dynamic predictions.

Ecological Impacts of Deer Overabundance

2004-11-02

Steeve D. Côté , Thomas P. Rooney , Jean‐Pierre Tremblay +2 more

▪ Abstract Deer have expanded their range and increased dramatically in abundance worldwide in recent decades. They inflict major economic losses in forestry, agriculture, and transportation and contribute to the … ▪ Abstract Deer have expanded their range and increased dramatically in abundance worldwide in recent decades. They inflict major economic losses in forestry, agriculture, and transportation and contribute to the transmission of several animal and human diseases. Their impact on natural ecosystems is also dramatic but less quantified. By foraging selectively, deer affect the growth and survival of many herb, shrub, and tree species, modifying patterns of relative abundance and vegetation dynamics. Cascading effects on other species extend to insects, birds, and other mammals. In forests, sustained overbrowsing reduces plant cover and diversity, alters nutrient and carbon cycling, and redirects succession to shift future overstory composition. Many of these simplified alternative states appear to be stable and difficult to reverse. Given the influence of deer on other organisms and natural processes, ecologists should actively participate in efforts to understand, monitor, and reduce the impact of deer on ecosystems.

New perspectives for estimating body condition from mass/length data: the scaled mass index as an alternative method

2009-09-10

Jordi Peig , Andy J. Green

Body condition is assumed to influence an animal's health and fitness. Various non‐destructive methods based on body mass and a measure of body length have been used as condition indices … Body condition is assumed to influence an animal's health and fitness. Various non‐destructive methods based on body mass and a measure of body length have been used as condition indices (CIs), but the dominant method amongst ecologists is currently the calculation of residuals from an ordinary least squares (OLS) regression of body mass against length. Recent studies of energy reserves in small mammals and starlings claimed to validate this method, although we argue that they did not include the most appropriate tests since they compared the CI with the absolute size of energy reserves. We present a novel CI (the ‘scaled mass index’) based on the central principle of scaling, with important methodological, biological and conceptual advantages. Through a reanalysis of data from small mammals, starlings and snakes, we show that the scaled mass index is a better indicator of the relative size of energy reserves and other body components than OLS residuals, performing better in all seven species and in 19 out of 20 analyses. We also present an empirical and theoretical comparison of the scaled mass index and OLS residuals as CIs. We argue that the scaled mass index is a useful new tool for ecologists.

Guidelines of the American Society of Mammalogists for the Use of Wild Mammals in Research

2007-05-24

William L. Gannon , Robert S. Sikes

Guidelines for use of wild mammal species Guidelines for use of wild mammal species

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ESTIMATING SITE OCCUPANCY, COLONIZATION, AND LOCAL EXTINCTION WHEN A SPECIES IS DETECTED IMPERFECTLY

2003-08-01

Darryl I. MacKenzie , James D. Nichols , James E. Hines +2 more

Few species are likely to be so evident that they will always be detected when present. Failing to allow for the possibility that a target species was present, but undetected, … Few species are likely to be so evident that they will always be detected when present. Failing to allow for the possibility that a target species was present, but undetected, at a site will lead to biased estimates of site occupancy, colonization, and local extinction probabilities. These population vital rates are often of interest in long-term monitoring programs and metapopulation studies. We present a model that enables direct estimation of these parameters when the probability of detecting the species is less than 1. The model does not require any assumptions of process stationarity, as do some previous methods, but does require detection/nondetection data to be collected in a manner similar to Pollock's robust design as used in mark–recapture studies. Via simulation, we show that the model provides good estimates of parameters for most scenarios considered. We illustrate the method with data from monitoring programs of Northern Spotted Owls (Strix occidentalis caurina) in northern California and tiger salamanders (Ambystoma tigrinum) in Minnesota, USA.

Functional landscape heterogeneity and animal biodiversity in agricultural landscapes

2010-11-18

Lenore Fahrig , Jacques Baudry , Lluı́s Brotons +6 more

Ecology Letters (2011) 14: 101–112 Abstract Biodiversity in agricultural landscapes can be increased with conversion of some production lands into ‘more‐natural’– unmanaged or extensively managed – lands. However, it remains … Ecology Letters (2011) 14: 101–112 Abstract Biodiversity in agricultural landscapes can be increased with conversion of some production lands into ‘more‐natural’– unmanaged or extensively managed – lands. However, it remains unknown to what extent biodiversity can be enhanced by altering landscape pattern without reducing agricultural production. We propose a framework for this problem, considering separately compositional heterogeneity (the number and proportions of different cover types) and configurational heterogeneity (the spatial arrangement of cover types). Cover type classification and mapping is based on species requirements, such as feeding and nesting, resulting in measures of ‘functional landscape heterogeneity’. We then identify three important questions: does biodiversity increase with (1) increasing heterogeneity of the more‐natural areas, (2) increasing compositional heterogeneity of production cover types and (3) increasing configurational heterogeneity of production cover types? We discuss approaches for addressing these questions. Such studies should have high priority because biodiversity protection globally depends increasingly on maintaining biodiversity in human‐dominated landscapes.

Temporal Variation in Fitness Components and Population Dynamics of Large Herbivores

2000-11-01

Jean‐Michel Gaillard , Marco Festa‐Bianchet , Nigel G. Yoccoz +2 more

▪ Abstract In large-herbivore populations, environmental variation and density dependence co-occur and have similar effects on various fitness components. Our review aims to quantify the temporal variability of fitness components … ▪ Abstract In large-herbivore populations, environmental variation and density dependence co-occur and have similar effects on various fitness components. Our review aims to quantify the temporal variability of fitness components and examine how that variability affects changes in population growth rates. Regardless of the source of variation, adult female survival shows little year-to-year variation [coefficient of variation (CV <10%)], fecundity of prime-aged females and yearling survival rates show moderate year-to-year variation (CV <20%), and juvenile survival and fecundity of young females show strong variation (CV >30%). Old females show senescence in both survival and reproduction. These patterns of variation are independent of differences in body mass, taxonomic group, and ecological conditions. Differences in levels of maternal care may fine-tune the temporal variation of early survival. The immature stage, despite a low relative impact on population growth rate compared with the adult stage, may be the critical component of population dynamics of large herbivores. Observed differences in temporal variation may be more important than estimated relative sensitivity or elasticity in determining the relative demographic impact of various fitness components.

Recovery of large carnivores in Europe’s modern human-dominated landscapes

2014-12-19

Guillaume Chapron , Petra Kaczensky , John D. C. Linnell +7 more

The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears ( Ursus arctos ), Eurasian … The conservation of large carnivores is a formidable challenge for biodiversity conservation. Using a data set on the past and current status of brown bears ( Ursus arctos ), Eurasian lynx ( Lynx lynx ), gray wolves ( Canis lupus ), and wolverines ( Gulo gulo ) in European countries, we show that roughly one-third of mainland Europe hosts at least one large carnivore species, with stable or increasing abundance in most cases in 21st-century records. The reasons for this overall conservation success include protective legislation, supportive public opinion, and a variety of practices making coexistence between large carnivores and people possible. The European situation reveals that large carnivores and people can share the same landscape.

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Gene Flow in Natural Populations

1985-11-01

M Slarkin

▪ Abstract The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in different ways and, as a consequence, … ▪ Abstract The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in different ways and, as a consequence, drawing different conclusions regarding both the ...Read More

Density as a Misleading Indicator of Habitat Quality

1983-10-01

Beatrice Van Horne

Current methods of evaluating wildlife habitat for management purposes can be arranged in a hierarchy of increasing generality. The most general level is evaluation of wildlife habitat for entire com- … Current methods of evaluating wildlife habitat for management purposes can be arranged in a hierarchy of increasing generality. The most general level is evaluation of wildlife habitat for entire com- munities on the basis of inferences drawn from vegetational structure. At the base of the hierarchy the high resolution studies, upon which accuracy at the higher hierarchical levels depends, usually assume that habitat quality for a species is positively correlated with the density of the species. If habitat quality for a wildlife species is a measure of the importance of habitat type in maintaining a particular species, habitat quality should be defined in terms of the survival and production characteristics, as well as the density, of the species occupying that habitat. Situations in which habitat quality thus defined is not expected to be positively correlated with density are described, along with the species and environmental characteristics that are most likely to produce these situations. Examples drawn from the literature in which density and habitat quality are not positively correlated are described. The positive correlation of density with habitat quality in specific instances cannot be assumed without supporting demographic data. J. WILDL. MANAGE. 47(4):893-901 The foundation of any wildlife habitat management plan is the ability to assess habitat quality accurately. Without this key ingredient, the effort put into care- fully prepared objectives and elegant cat- egorizations of habitat types is largely wasted. Yet biologists often dwell on ob- jectives and categories while treating lightly the assumptions implicit in their assessments of habitat quality. For in- stance, they seldom question the assump- tion that the density of a species in a hab- itat is a direct measure of the quality of that habitat. Perhaps this is because any more accurate investigation of habitat quality to truly reflect the importance of that habitat in maintaining wildlife species populations must be intensive, often at the expense of the broader information base that could be achieved by simple surveys. Such surveys are a particularly common means of evaluating nongame wildlife habitat. The objectives of this paper are to pro- vide some examples of situations in which this correlation does not hold, and to make predictions regarding species and envi- ronmental types for which the density- habitat quality relationship is likely to be decoupled. In such cases, management policies based directly on species abun- dance may be misleading and these errors may be amplified when management ap- proaches are restricted to the higher levels of the hierarchy. This paper is dedicated to the late 0. C. Wallmo, who was always eager to dis- cuss ideas and whose refusal to be any- thing but completely honest in evaluating his own ideas, objectives, and research ideas, as well as those of others, set an example for us to follow.

Farming and the Fate of Wild Nature

2004-12-24

Rhys E. Green , Stephen J. Cornell , Jörn P. W. Scharlemann +1 more

World food demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on wild species and habitats. We show that … World food demand is expected to more than double by 2050. Decisions about how to meet this challenge will have profound effects on wild species and habitats. We show that farming is already the greatest extinction threat to birds (the best known taxon), and its adverse impacts look set to increase, especially in developing countries. Two competing solutions have been proposed: wildlife-friendly farming (which boosts densities of wild populations on farmland but may decrease agricultural yields) and land sparing (which minimizes demand for farmland by increasing yield). We present a model that identifies how to resolve the trade-off between these approaches. This shows that the best type of farming for species persistence depends on the demand for agricultural products and on how the population densities of different species on farmland change with agricultural yield. Empirical data on such density-yield functions are sparse, but evidence from a range of taxa in developing countries suggests that high-yield farming may allow more species to persist.

FOOD AS A LIMIT ON BREEDING BIRDS: A LIFE-HISTORY PERSPECTIVE

1987-11-01

Thomas E. Martin

Statistical inference from capture data on closed animal populations

1978-01-01

David L. Otis , Kenneth P. Burnham , Gary C. White +1 more

2016 Guidelines of the American Society of Mammalogists for the use of wild mammals in research and education:

2016-05-28

Robert S. Sikes

Guidelines for use of wild mammal species in research are updated from Sikes et al. (2011) . These guidelines cover current professional techniques and regulations involving the use of mammals … Guidelines for use of wild mammal species in research are updated from Sikes et al. (2011) . These guidelines cover current professional techniques and regulations involving the use of mammals in research and teaching; they also incorporate new resources, procedural summaries, and reporting requirements. Included are details on capturing, marking, housing, and humanely killing wild mammals. It is recommended that Institutional Animal Care and Use Committees (IACUCs), regulatory agencies, and investigators use these guidelines as a resource for protocols involving wild mammals, whether studied in the field or in captivity. These guidelines were prepared and approved by the American Society of Mammalogists (ASM), in consultation with professional veterinarians experienced in wildlife research and IACUCs, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals. The current version of these guidelines and any subsequent modifications are available online on the Animal Care and Use Committee page of the ASM website ( http://mammalogy.org/uploads/committee_files/CurrentGuidelines.pdf ). Additional resources pertaining to the use of wild animals in research are available at: http://www.mammalsociety.org/committees/animal-care-and-use#tab3 .Los lineamientos para el uso de especies de mamíferos de vida silvestre en la investigación con base en Sikes et al. (2011) se actualizaron. Dichos lineamientos cubren técnicas y regulaciones profesionales actuales que involucran el uso de mamíferos en la investigación y enseñanza; también incorporan recursos nuevos, resúmenes de procedimientos y requisitos para reportes. Se incluyen detalles acerca de captura, marcaje, manutención en cautiverio y eutanasia de mamíferos de vida silvestre. Se recomienda que los comités institucionales de uso y cuidado animal (cifras en inglés: IACUCs), las agencias reguladoras y los investigadores se adhieran a dichos lineamientos como fuente base de protocolos que involucren mamíferos de vida silvestre, ya sea investigaciones de campo o en cautiverio. Dichos lineamientos fueron preparados y aprobados por la ASM, en consulta con profesionales veterinarios experimentados en investigaciones de vida silvestre y IACUCS, de quienes cuya experiencia colectiva provee un entendimiento amplio y exhaustivo de la biología de mamíferos no-domesticados. La presente versión de los lineamientos y modificaciones posteriores están disponibles en línea en la página web de la ASM, bajo Cuidado Animal y Comité de Uso: ( http://mammalogy.org/uploads/committee_files/CurrentGuidelines.pdf ). Recursos adicionales relacionados con el uso de animales de vida silvestre para la investigación se encuentran disponibles en ( http://www.mammalsociety.org/committees/animal-care-and-use#tab3 ).

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The interplay between habitat availability and population differentiation

2012-01-01

Yvonne I. Verkuil , Theunis Piersma , Joop Jukema +3 more

Biodiversity: The ravages of guns, nets and bulldozers

2016-08-01

Sean L. Maxwell , Richard A. Fuller , Thomas M. Brooks +1 more

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The Mammals of North America

1959-09-15

W. Frank Blair , E. Raymond Hall , Keith R. Kelson

Group Selection and Kin Selection

1964-03-01

John Maynard Smith

IUCN Red List of Threatened Species

2012-08-01

Natural Selection in the Wild

1987-05-01

Daniel J. Schoen , J. A. Endler

Introduction to Distance Sampling

2001-07-19

S. T. Buckland , David R. Anderson , K P Burnham +3 more

Abstract Offers a comprehensive introduction to distance sampling, a statistical method used by many biologists and conservationists to estimate animal abundance. The text discusses point transect sampling and line transect … Abstract Offers a comprehensive introduction to distance sampling, a statistical method used by many biologists and conservationists to estimate animal abundance. The text discusses point transect sampling and line transect sampling and also describes several other related techniques. There are updates on study design and field methods, laser range finders, theodolites and the GPS and advice is given on a wide range of survey methods. Analysis methods have also been generalized, through the use of various types of multiplier and exercises for students in wildlife and conservation management are included.

Gloucestershire Historic Wildlife Sightings prior to 1st Jan 2000

2022-01-01

Uknbn

This dataset comprises validated species records with a sample/sighting date earlier than 1st January, 2000, as received and collated by Gloucestershire Centre for Environmental Records (GCER). This replaces the pre-2000 … This dataset comprises validated species records with a sample/sighting date earlier than 1st January, 2000, as received and collated by Gloucestershire Centre for Environmental Records (GCER). This replaces the pre-2000 records of our previous historic dataset. The records cover all the groups recorded in the county, including vascular and lower plants, fungi and lichens, birds and animals. See the "Additional Information" section for details of records which have NOT been included. In general, public viewers may see these records as a 1km distribution map where the resolution of the original records allows. Zero abundance records are not included. Some records are only available at a lower resolution, e.g. tetrad records (2km x 2km). Unvalidated, ad hoc, "negative" (i.e. zero abundance), known doubtful and purely anecdotal records are not included. See the "Additional Information" section for details of datasets held by GCER which have NOT been included in this upload because they are already available on the NBN Gateway via another data provider. The uploaded data includes some additional attributes such as system codes. These are for use by GCER and national conservation agencies.

Vertebrate Zoology Division - Mammalogy, Yale Peabody Museum

2024-01-01

Larry Gall

The mammal collection in the Yale Peabody Museums’s Division of Vertebrate Zoology, although small, is worldwide in coverage, and is used principally for teaching. The 5,086 mammal skins (over 720 … The mammal collection in the Yale Peabody Museums’s Division of Vertebrate Zoology, although small, is worldwide in coverage, and is used principally for teaching. The 5,086 mammal skins (over 720 species) date from the 19th century, and includes several rare and endangered species: the African elephant, black rhinoceros, orangutan, mountain gorilla, red wolf, black-footed ferret and snow leopard. The skeleton collection is likewise small (4,776 specimens representing over 770 species), but historically important, and contains a disproportionate number of large animals, among them one of only 7 complete skeletons of the now extinct quagga, and a large series of buffalo skulls from the 1870s.

Population trends of jaguars in a tropical forest in southern Mexico

2025-06-25

Fernando M. Contreras‐Moreno , Lizardo Cruz‐Romo , Daniel Jesús‐Espinosa +5 more | Conservation Science and Practice

Abstract Jaguars are the largest carnivores in the Neotropics with high conservation priority. Population trends of top predators such as jaguars provide valuable information on demography, use of habitats, and … Abstract Jaguars are the largest carnivores in the Neotropics with high conservation priority. Population trends of top predators such as jaguars provide valuable information on demography, use of habitats, and individual interactions, which serve to establish conservation and management actions. We studied spatiotemporal population trends of jaguars in a tropical rainforest in the Calakmul Biosphere Reserve (CBR) located in southern Mexico. We used sex‐structured open capture–recapture models (OSCR) to estimate jaguar population density related to environmental variables and overlap of individual activity centers to evaluate their spatial interactions. To measure the overlap in the circadian activity, a kernel estimator was used, and intervals of time among pairs of co‐occurrences were analyzed to detect spatiotemporal associations between individuals. The population density of jaguars was 1.03 individuals/100 km 2 (0.59 and 0.44 individuals/100 km 2 for males and females, respectively). Capture probabilities differed between males and females probably due to differences in their use of human‐made trails. Despite temporal variations in population density and individual activity centers, these appeared to have no effect on parameters. Instead, we observed a relationship between (1) distance to roads and detection, (2) net primary productivity and movement, and (3) distance to borders and population density. Temporal circadian overlap showed low values between sexes, although slightly higher values were observed in the rainy seasons. Overall, we found jaguars segregating in space and time. We highlight the importance of the CBR in maintaining continuous suitable habitat and reducing edge effects detrimental to jaguar population density.

A Crested Caracara (Caracara plancus) Nest Site Inside a Building in Southern Continental Patagonia, Santa Cruz, Argentina

2025-06-25

Miguel D. Saggese , Agustín I. E. Quaglia , Maite B. Amorós +2 more | Journal of Raptor Research

Small snakes, big cities: population genetics of urban Dekay’s brown snake (Storeria dekayi) in New Jersey

2025-06-24

Tianqi Huang , Isaac Overcast , Arianna Kuhn +2 more | Journal of Heredity

Abstract Despite the unprecedented rate of global urbanization, a diverse array of taxa are supported in urban areas. However, the long-term persistence of urban wildlife cannot be guaranteed due to … Abstract Despite the unprecedented rate of global urbanization, a diverse array of taxa are supported in urban areas. However, the long-term persistence of urban wildlife cannot be guaranteed due to the various adverse effects that come with urbanization, such as resource depletion and reduced gene flow. Accordingly, it is imperative to evaluate the health and viability of urban wildlife, particularly of species that are underrepresented in the existing literature, like herpetofauna. Genomic techniques can provide critical insights into urban wildlife health and population viability. Here, we generated a ddRADseq dataset of 162 Dekay’s brown snakes (Storeria dekayi) among 11 locations with different urbanization magnitudes across New Jersey, USA, and examined the population genetic patterns of this common urban reptile. While genetic diversity was not severely reduced within those populations, we uncovered the presence of genetic differentiation and structuring across them, especially for those from the most urbanized areas. Deviations of interpopulation structure from their geographic distributions might reflect either habitat alteration or human intervention in recent history. Landscape genetic analyses revealed the presence of an isolation-by-distance relationship that was only significant within a short spatial distance of 1500 m. Most urban populations also displayed lower-than-expected historic migration and diversity rates, but some remained genetically connected and diverse. To conclude, our study can serve as a useful guide for population genomic studies on urban herpetofauna. Based on our results, urbanization is likely to impact interpopulation genetic connectivity, but to have limited effects on intrapopulation genetic diversity of small-bodied, terrestrial urban dwellers.

Fallow deer abundances and age profiles indicate opportunistic hunting in the Middle Paleolithic Levant

2025-06-24

Meir Orbach , Reuven Yeshurun | Journal of Archaeological Science

Measuring poverty and socio-economic determinants of Sumatran elephant (Elephas maximus sumatranus) populations and conflicts in Aceh, Indonesia

2025-06-24

Andrio Wibowo | Research Square (Research Square)

<title>Abstract</title> As one of countries which has the large tropical forests in the world, Indonesia has experienced serious animal-human conflicts and defaunation. One example is the population declines and conflicts … <title>Abstract</title> As one of countries which has the large tropical forests in the world, Indonesia has experienced serious animal-human conflicts and defaunation. One example is the population declines and conflicts between human and elephant. This study tries to extend and explore how the socio-economic and poverty dimensions impact Sumatran elephant (<italic>Elephas maximus sumatranus</italic>) population in Aceh, one of provinces in Indonesia that still has large elephant populations. The method used in here is mapping of data including deforestation, forest covers, B40 percentage, education indicator, elephant populations and conflicts. The results show the B40 percentage and population density have similar pattern with the deforestation, elephant conflicts and populations. High B40 percentages in western parts of Aceh are related to the absence of elephant populations even though there are vegetation covers in here. Tertiary educations do not have effect in reducing the human and elephant conflicts. This informs that the education curriculum should be revisited by emphasizing more on endemic animal conservation topics.

Attitudes of local communities to wildlife conservation and non-consumptive, alternative income sources, near Kruger National Park, South Africa

2025-06-24

Tom P. Moorhouse , Herbert Ntuli , Prince Nketiah +2 more | Biological Conservation

Borrelia Lineages Adjacent to Zoonotic Clades in Black Flying Foxes (Pteropus alecto), Australia, 2018–2020

2025-06-24

Taylor B. Verrett , Caylee Falvo , Evelyn Benson +7 more | Emerging infectious diseases

We explored the role of black flying foxes (Pteropus alecto) in Australia as reservoirs of Borrelia bacteria. We found bats infected with 2 Borrelia haplotypes phylogenetically distinct from Lyme or … We explored the role of black flying foxes (Pteropus alecto) in Australia as reservoirs of Borrelia bacteria. We found bats infected with 2 Borrelia haplotypes phylogenetically distinct from Lyme or relapsing fever clades. Efforts to sample black flying foxes and their ectoparasites are needed to evaluate zoonotic potential of those Borrelia lineages.

First record of a nest of Vultur gryphus Linnaeus, 1758 (Cathartiformes, Cathartidae), in Paccha district, Junin region, Peru

2025-06-24

Héctor Hugo Pérez Vega , Luis Castillo , Martin Herbert +2 more | Check List

Vultur gryphus Linnaeus, 1758, Andean Condor, is the world&rsquo;s largest soaring birds. It inhabits the Andes mountains and is categorized as Vulnerable in the IUCN Red List. In 2024, members … Vultur gryphus Linnaeus, 1758, Andean Condor, is the world&rsquo;s largest soaring birds. It inhabits the Andes mountains and is categorized as Vulnerable in the IUCN Red List. In 2024, members of the Denver Zoo Conservation Alliance conducted exploratory field trips to Junin and Pasco regions of Peru to assess whether these areas are critical for the conservation and long&#8209;term survival of this species. Using direct observation, 11 individuals were counted, including seven adults and four juveniles, and with Remote Piloted Aircraft System, three individuals were observed: one chick next to a nest and, nearby, two adults. These findings are crucial to the research and conservation of V. gryphus in Peru because of the limited historical research on condor nesting. We recommend that the areas where our new records were recorded should be a priority for the conservation of condors.

From encounter to death: Which stages of predation are considered within livestock depredation research?

2025-06-24

Anna Rouviere , Robert A. Montgomery | Biological Conservation

Rare Camera Trap Records of Three Small Carnivores in Northwest Namibia

2025-06-24

John Heydinger , Uakendisa Muzuma | African Journal of Wildlife Research

Automated methods for processing camera trap video data for distance sampling

2025-06-23

Trevor M. Bak , Richard J. Camp , Matthew D. Burt +1 more | Pacific Conservation Biology

Context Population monitoring is an essential need for tracking biodiversity and judging efficacy of conservation management actions, both globally and in the Pacific. However, population monitoring efforts are often temporally … Context Population monitoring is an essential need for tracking biodiversity and judging efficacy of conservation management actions, both globally and in the Pacific. However, population monitoring efforts are often temporally inconsistent and limited to small scales. Motion-activated cameras (‘camera traps’) offer a way to cost-effectively monitor populations, but they also generate large amounts of data that are time intensive to process. Aims To develop an automated pipeline for processing videos of ungulates (Philippine deer, Rusa marianna; and pigs, Sus scrofa) on Andersen Air Force Base in Guam. Methods We processed camera videos with a machine learning model for object detection and classification. To estimate density using distance sampling methods, we used a separate machine learning model to estimate the distance of target animals from the camera. We compared density estimates generated using manual versus automated methods and assessed accuracy and processing time saved. Key results The object detection and classification model achieved an overall accuracy >80% and F1 score ≥0.9 and saved 36.9 h of processing time. The automated distance estimation was fairly accurate, with a 1.1 m (±1.4 m) difference from manual distance estimates, and saved 16.8 h of processing time. Density estimates did not differ substantially between manual and automated distance estimation. Conclusions Machine learning models accurately processed camera videos, allowing efficient estimates of density from camera data. Implications Further adoption of motion-activated cameras coupled with automated processing could lead to continuous, large-scale monitoring of populations, helping to understand and address changes in biodiversity.

Flexible movement kernel estimation in habitat selection analyses with generalized additive models

2025-06-23

Rafael Arce Guillen , Jennifer Pohle , Florian Jeltsch +4 more | Methods in Ecology and Evolution

Abstract Habitat selection analysis includes resource selection analysis (RSA) and step selection analysis (SSA). These frameworks are used in order to understand space use of animals. Particularly, the SSA approach … Abstract Habitat selection analysis includes resource selection analysis (RSA) and step selection analysis (SSA). These frameworks are used in order to understand space use of animals. Particularly, the SSA approach specifies the area available to the animal through a movement kernel. This movement kernel is typically defined as the product of independent parametric distributions of step lengths (SLs) and turning angles (TAs). However, these independence and parametric assumptions may not always be plausible for real data where short SLs are often correlated with large TAs and vice versa. The objective of this paper was to relax the need for parametric distributions of step lengths and turning angles, using generalized additive models (GAMs) and the R ‐package mgcv , based on the work of Klappstein et al. (2024). For this, we propose specifying the movement kernel as a bivariate tensor product, rather than independent distributions of SLs and TAs. In addition, we account for residual spatial autocorrelation in this GAM approach. Using simulations, we show that the tensor product approach accurately estimates the underlying movement kernel and that the fixed effects of the model are not biased. In particular, if the data are simulated with a copula distribution for SL and TA, that is if the independence assumption for SL and TA does not hold, the GAM approach produces better estimates than the classical approach. In addition, including a bivariate tensor product in the model leads to a better uncertainty estimation of the model parameters and lower mean‐squared error of the model predictions. Incorporating a bivariate tensor product solves the problem of assuming parametric distributions and independence between SLs and TAs. This offers greater flexibility and makes the analysis of real data more reliable.

Orangutan population monitoring methods: Strengths, challenges, and opportunities

2025-06-23

Valentino Koloski , Marijke van Kuijk , Muhammad Ali Imron +4 more | Biological Conservation

The community context of trophic cascades

2025-06-23

Blake Matthews | Journal of Animal Ecology

Research Highlights: Baker, R., Whiteman, H., & Mott, C. L. (2025). Predation alters community structure through multiple trophic cascades. Journal of Animal Ecology. The trophic interactions of predators can strongly … Research Highlights: Baker, R., Whiteman, H., & Mott, C. L. (2025). Predation alters community structure through multiple trophic cascades. Journal of Animal Ecology. The trophic interactions of predators can strongly influence the biomass structure and species composition of ecosystems and can result in trophic cascades-namely, when predators reduce the biomass of their prey (e.g. grazers) and this indirectly increases the biomass of organisms lower in the food chain (e.g. primary producers). There has been long-standing interest in the causes of variation in the strength of trophic cascades and in the underlying mechanisms by which predators affect organisms lower in the food chain. In a recent study, Baker et al. (2025) experimentally test a specific hypothesis about how the size variation of a predator population (the predatory mole salamander: Ambystoma talpoideum) indirectly affects primary producers (i.e. periphyton) in pond ecosystems via cascading trophic interactions. In an outdoor mesocosm experiment, the authors show that predators triggered trophic cascades along two food chains, namely those supported by periphyton (a green chain) and detritus (a brown chain). Contrary to their expectations, predator populations with a wide range of body size caused stronger trophic cascades than those with a narrow range of body size. Their findings illustrate the importance of testing ecological theory in semi-natural environmental settings that are open to dispersing organisms and doing so over long enough time periods to observe the relevant community context of trophic interactions.

A framework to categorise the cultural significance of freshwater fauna

2025-06-23

Phoebe Griffith , Sonja C. Jähnig , Rebecca E. Tharme +7 more | Research Square (Research Square)

<title>Abstract</title> Freshwater ecosystems support rich biological and cultural diversity, each enhanced through biocultural co-evolution. However freshwater species, and their relationships with people, face escalating pressures from global change, threatening ecosystem … <title>Abstract</title> Freshwater ecosystems support rich biological and cultural diversity, each enhanced through biocultural co-evolution. However freshwater species, and their relationships with people, face escalating pressures from global change, threatening ecosystem function and human wellbeing. Addressing this crisis effectively and ethically requires transdisciplinary approaches that recognise the complex, culturally embedded interactions between people and freshwater fauna. Existing frameworks for integrating the cultural and ecological dimensions of freshwater fauna are either too general or conceptually misaligned to support practical application, and are often based on binaries such as ‘tangible and intangible’ that artificially segregate meaning and practice. To bridge this gap, we developed a novel framework for systematically categorising the cultural significance of freshwater fauna, drawing on pre-existing frameworks and human-freshwater-fauna interactions (n = 612) from interdisciplinary literature. The resulting framework comprises seven overarching domains – Consumptive Use; Cultural Landscapes, Sites and Stewardship; Knowledge Systems; Worldviews, Beliefs and Identities; Cultural and Social Practices; Recreation, Leisure and Tourism; and Creative Expression – each subdivided into defined categories and subcategories. Applicable across diverse cultural, taxonomic and geographic contexts, our framework provides a pragmatic tool to support more holistic and inclusive approaches to freshwater ecosystem research, management, governance, and cross-cultural cooperation.

Trunk Wash Training in African Elephants ( Loxodonta Africana )

2025-06-23

Charlotte Jones | Animal Behaviour and Welfare Cases

Abstract The behaviour of a “trunk wash” for an elephant is used in captivity as a routine procedure for in-house monitoring for tuberculosis (TB) and pre-transfer health checks. Any animal … Abstract The behaviour of a “trunk wash” for an elephant is used in captivity as a routine procedure for in-house monitoring for tuberculosis (TB) and pre-transfer health checks. Any animal training within a zoological institution should have a net welfare benefit to the animal. By training an elephant to voluntarily take part in this procedure, it will benefit the animal’s welfare by reducing stress and the need for sedation to obtain the sample. It will also greatly reduce the safety risk to the elephant and staff involved. This case study describes the training of one female African elephant that is in a protected contact management system, whereby the keeper and animal interaction is carried out with a barrier in between, learning to take part in a voluntary trunk wash. It will also cover the training plan and considerations required before carrying out the training. Information © The Author 2025

Observations of Osteophagia, Kleptoparasitism, and Cannibalism in American Black Bear Diet Via Animal-Borne Camera Collars in the Central Appalachian Mountains

2025-06-23

Brogan E. Holcombe , Kathryn Bayne , Robert S. Alonso +2 more | Southeastern Naturalist

Predation on the threatened Carnaby’s cockatoo (Zanda latirostris) by feral cats (Felis catus)

2025-06-22

Peter R. Mawson , Rick Dawson , Brooke Richards +1 more | Pacific Conservation Biology

Context Feral cats (Felis catus) prey on a wide range of Australian native bird species, with most records related to smaller, ground-dwelling or ground-nesting species. Aims This study examined the … Context Feral cats (Felis catus) prey on a wide range of Australian native bird species, with most records related to smaller, ground-dwelling or ground-nesting species. Aims This study examined the impact of feral cat predation on endangered Carnaby’s cockatoo (Zanda latirostris), a large obligate hollow-nesting species. Methods Cat predation was measured during a study into the breeding ecology of Carnaby’s cockatoo at a long-term study site in the northern wheatbelt of Western Australia. Key results Feral cats predated Carnaby’s cockatoo adult females in their nest hollow, their nestlings, and eggs in at least three out of 38 years. When it occurred in those 3 years, the feral cat predation impact, expressed as a percentage of breeding attempts on cockatoo nesting were 5.2%, 11.6%, and 24.1%. The increase in predation rate in the year with the highest recorded rate coincided with the breeding season following an intense 8-month drought in mid-western Western Australia, which likely had an adverse impact on prey species more often consumed by feral cats. Conclusion The results suggest that predation by cats can be a significant threat to Carnaby’s cockatoo because it reduces the survival of adult breeding females and recruitment of fledglings. Implications Control of feral cats by local-scale shooting and cage trapping have both been used to achieve short-term success, offering a possible means of mitigating the long-term impact of feral cats at the study site, and potentially elsewhere.

Assessing Human-Wildlife Conflict in Lakki Marwat, Pakistan: Economic Impacts and People’s Perceptions

2025-06-21

Tanveer A. Khan , Shakeel Ahmad , Tahir Mehmood +5 more | European Journal of Wildlife Research

Hoofed animal detection in UAV thermal images using Balanced Random Forest and CNN features

2025-06-21

Dorota Włodarczyk , G. Jóźków | Reports on Geodesy and Geoinformatics

Abstract Wildlife monitoring is vital to conservation efforts and the prevention of animal-related negative impacts on human activities and ecosystems. The use of Unmanned Aerial Vehicles (UAVs) enables data collection … Abstract Wildlife monitoring is vital to conservation efforts and the prevention of animal-related negative impacts on human activities and ecosystems. The use of Unmanned Aerial Vehicles (UAVs) enables data collection with no harm to wildlife and in difficult field conditions. This study proposes a method of detecting hoofed animals in UAV-acquired thermal images, addressing the challenges of low-resolution thermal imaging and the presence of other heated objects hindering simple temperature analysis and image segmentation. The proposed method uses machine learning algorithms and is designed to work with a limited size of training dataset. The method consists of an initial segmentation step that detects potential animals based on thermal and geometrical signatures, followed by classification using a Balanced Random Forest (BRF) algorithm. One of the key aspects of the proposed method is the use of geometric and thermal features along with multi-scale Convolutional Neural Network (CNN) extracted feature representations in BRF. The benefit of the BRF is its speed, little requirement regarding the amount of training data, and its capacity to work with an imbalanced number of objects in different classes. The dataset was collected during two UAV flights over a fenced enclosure with wild hoofed animals. The proposed approach showed high efficiency, achieving an overall accuracy of 90%. These results confirm the feasibility of UAV-based animal detection based solely on thermal images collected during the day and showing many other heated objects. The method provides a solution for wildlife monitoring, with potential adaptability to different species and further applications.

Birds as Biodiversity Beacons: Identifying Conservation Priority Areas Through Multi-Dimensional Diversity in China

2025-06-21

Fei Duan , Shuyi Zhu , Xiaoyun Shi +2 more | Diversity

Biodiversity conservation plays a pivotal role in achieving sustainable development and fostering harmonious coexistence between humans and nature. This study identifies avian conservation priority areas across China by analyzing multi-dimensional … Biodiversity conservation plays a pivotal role in achieving sustainable development and fostering harmonious coexistence between humans and nature. This study identifies avian conservation priority areas across China by analyzing multi-dimensional biodiversity, incorporating species diversity, functional diversity, and phylogenetic diversity. Through systematic conservation planning using Zonation version 4 software, we delineated priority areas across these diversity dimensions. Our results demonstrate a distinct south-to-north diversity gradient in China’s avifauna, with functional and phylogenetic diversity hotspots concentrated in Yunnan Province, the Hengduan Mountains, Hainan Island, Taiwan Island, and southeastern coastal regions. The identified priority conservation areas cover 14.6% of China’s terrestrial territory, protecting 89.8% of the country’s bird species—including 93.5% of endemic species and 88.9% of critically endangered species. Notably, existing nature reserves encompass merely 8.1% of these priority areas, revealing substantial conservation gaps within the current protection framework. Building upon China’s 3C Zoning Framework (Cities and farms, Shared landscapes, and Large wild areas), we propose zone-specific conservation strategies, with particular emphasis on strengthening protected area networks in the eastern coastal regions and the middle-lower Yangtze River basin, where urbanization pressures are most acute. These findings highlight the critical importance of incorporating multi-dimensional diversity in conservation planning and offer novel perspectives for optimizing China’s protected area system.

Neutral effects of low‐intensity dog training on northern bobwhite vital rates

2025-06-20

Kyle N. Magdziuk , Justin Rectenwald , D. Clay Sisson +1 more | Wildlife Biology

Indirect effects of hunting can lead to changes in population dynamics, which can be caused by trait‐mediated effects such as, but not limited to, changes in behavior, reproduction, and physiological … Indirect effects of hunting can lead to changes in population dynamics, which can be caused by trait‐mediated effects such as, but not limited to, changes in behavior, reproduction, and physiological responses. Our understanding of the effects of activities associated with hunting such as dog training may incur trait‐mediated effects, and ultimately indirect effects to wildlife populations are underrepresented. We conducted a two‐year study on a relatively high‐density wild bobwhite population to identify potential impacts of disturbance caused by the most common levels of spring dog training on bobwhite survival and reproduction. About 34% of coveys across all training events were not available to be encountered. Those remaining for possible encounters were typically encountered once (39%) or not at all (32.5%), whereas 14.6% and 12.8% were encountered twice or three times, respectively. We found no effect of the categorical effects of treatment or encounters on adult or nest survival, clutch size, hatchability, or nest propensity. Additionally, we found no effect of treatment or encounters on fecundity for both years and for both treatments. The neutral results of our study are likely attributed to intentionally low encounter rates. Future studies should focus on scenarios where disturbances are more frequent, and food resources are likely more limited.

Mapping habitat suitability of the brown bear in Artvin-Şavşat region, Turkey

2025-06-20

Ahmet Acarer , Ahmet Mert | Ursus

Navigating multi-predator dynamic risk landscapes in anthropogenic environments: spatio-temporal plasticity in roe deer habitat selection

2025-06-20

Benedikt Gehr , Adam F. Smith , Simone Ciuti +7 more | Research Square (Research Square)

<title>Abstract</title> <italic><bold>Context</bold></italic><bold> </bold>Non-lethal and lethal human activities such as hunting or agricultural practices strongly shape the movement and behaviour of wildlife populations. The recent return of natural predators in parts … <title>Abstract</title> <italic><bold>Context</bold></italic><bold> </bold>Non-lethal and lethal human activities such as hunting or agricultural practices strongly shape the movement and behaviour of wildlife populations. The recent return of natural predators in parts of the world complexifies the risk landscape for prey in anthropogenic ecosystems. A large-scale analysis is strongly needed to disentangle how hunted species manage to navigate the dynamic landscape of risk between human and natural predators to persist within human-dominated landscapes. <italic><bold>Objectives</bold></italic> We investigated how roe deer may flexibly adjust the selection for open and forest habitats to trade-off between hunting and natural predation risk. We used a large dataset across Europe with areas with and without risk from hunting and lynx, while controlling for non-lethal human disturbance using the Human Footprint Index. <italic><bold>Methods</bold></italic><bold> </bold>We used integrated step selection analysis at diel and seasonal temporal scales to look at selection for open vs. forest habitats across sites differing in the occurrence and timing of the hunting season, presence of lynx, human disturbance while controlling for resource availability. <bold>Results </bold>We found only weak evidence that deer shifted habitat selection in presence of hunting, while lynx predation risk was associated with greater preference for open habitat at night. When both hunting and lynx co-occurred, deer selection for open and forest was driven by the presence of lynx rather than hunters. In absence of any lethal risk, deer habitat selection was associated with non-lethal human disturbance. Time of day and season were important determinants of deer habitat selection. <italic><bold>Conclusions</bold></italic><bold> </bold>We found a consistent response to predation risk by lynx, while hunting induced a more variable response, probably because being less predictable. Adjusting habitat selection and activity at different temporal scales as a function of these relative risks allows ungulates to navigate in the dynamic multi-risk landscape of Europe’s anthropogenic environments. Our results set the empirical baseline which will help to disentangle habitat selection and activity shifts in future hunter-predator-prey studies, as the large predator guild in Europe further re-establishes, and human impact on natural habitats increases.

Assessing the Design and Management of Protected Areas

2025-06-20

Marco Navarro , Melina Paredes , Miguel Angel Pezo Sardón +1 more | Cuadernos de Investigación Geográfica

Coastal desert ecosystems, such as the Lomas and Tillandsiales, are essential for the well-being of local populations, providing vital ecosystem goods and services, including climate regulation and water supply. These … Coastal desert ecosystems, such as the Lomas and Tillandsiales, are essential for the well-being of local populations, providing vital ecosystem goods and services, including climate regulation and water supply. These ecosystems are recognized as significant conservation areas at the national level. However, the Lomas and Tillandsiales in Tacna have been adversely affected and ecologically degraded due to uncontrolled population growth and inadequate regulation of human activities, such as agriculture, mining, and livestock grazing. Therefore, it is crucial to implement effective conservation strategies. Despite this need, when governmental entities delineate territories for potential protected areas, existing land use is often prioritized, leading to the exclusion of areas under current use rather than considering geographical criteria or ecological attributes of these vital ecosystems. This practice raises questions about the effectiveness of conservation efforts. To assess the proposed polygons for new protected areas by regional authorities, we compared these with natural ecosystem boundaries using various geographical tools. This comparison revealed substantial differences in geographical, ecological, and landscape metrics, indicating a decrease in ecological similarity and potentially lower effectiveness for conservation. We identified variations in geomorphological and morphometric diversity, with extreme cases showing coefficients of variability of 56% for the Gravelius index, 52% for the altitude index, and 43% for the morphometric protection index. These factors are critical as they strongly correlate with biodiversity, ecological processes, and the provision of ecosystem services, which are the main goals of conservation. Given these discrepancies, the newly proposed conservation area may inadequately fulfill its objectives. Once designated, the authorities should design and implement a management model that prioritizes expanding the protected areas to their natural limits, promoting restoration, and conducting ongoing monitoring of the metrics outlined in this research. Conservation should not merely involve declaring a spatial area as a reserve; it also requires defining these spaces based on tools and geographical knowledge to ensure the adequate protection and conservation of the Lomas and Tillandsiales ecosystems.

Daily visitation patterns and consumption of fleshly fruits of invasive alien plants by wild southern African ungulates

2025-06-20

Lindelwa S. Msweli , Manqoba M. Zungu , Christophe Baltzinger +1 more | Mammalian Biology

Abstract Endozoochorous seed dispersal by ungulates has received increased attention. However, ungulates’ daily visitation patterns and fruit consumption of the fleshly fruits of invasive alien plants (IAPs) are poorly documented. … Abstract Endozoochorous seed dispersal by ungulates has received increased attention. However, ungulates’ daily visitation patterns and fruit consumption of the fleshly fruits of invasive alien plants (IAPs) are poorly documented. Using camera trapping, we documented wild southern African ungulates interactions with three freshly-fruited IAPs, i.e. lantana ( Lantana camara) , bugweed ( Solanum mauritianum) and cochineal prickly-pear ( Opuntia monacantha ) in KwaZulu-Natal, South Africa. We determined the community of potential ungulate seed dispersers of the IAPs, the daily IAP interaction patterns and quantified relative fruit consumption by ungulates. The level of IAP fruit consumption was significantly different among ungulate species and IAPs and varied with time of day. Giraffe ( Giraffa camelopardalis giraffa ), bushbuck ( Tragelaphus sylvaticus ), impala ( Aepyceros melampus ), nyala ( T. angasii ) and greater kudu ( T. strepsiceros ) showed the highest relative fruit consumption rate, respectively, while the lowest was for blue wildebeest ( Connochaetes taurinus ), and zebra ( Equus quagga ). Impala and greater kudu were recorded interacting with the IAPs from 24h00-06h00, giraffe and nyala from 06h00-12h00, and bushbuck from 18h00-06h00. Overall, L. camara was visited mostly during the diurnal-afternoon; however, O. monacantha during the nocturnal-morning and S. mauritianum during the nocturnal-night. The main ungulates potentially dispersing L. camara were giraffe and bushbuck. Impala and greater kudu were the main potential dispersal vectors for O. monacantha . Our study showed that camera trapping is useful for determining the interactions between ungulates and IAPs, which is crucial for understanding their potential contribution to the dispersal dynamics of IAPs in African savannas.

Security cameras: a tool for reducing risks and increasing selectivity in wildlife trapping

2025-06-20

Eduardo A. Silva‐Rodríguez , Javiera P. Jara-Díaz , Gilberto A. Castillo +3 more | Mammalian Biology

Habitat Requirements of the Grey-Headed Woodpecker in Lowland Areas of NE Poland: Evidence from the Playback Experiment

2025-06-20

Grzegorz Zawadzki , Dorota Zawadzka | Birds

The grey-headed woodpecker (Picus canus) (GHW) is one of the least-studied European woodpeckers, listed in Annex I of the Birds Directive. We examined the key environmental characteristics that determine the … The grey-headed woodpecker (Picus canus) (GHW) is one of the least-studied European woodpeckers, listed in Annex I of the Birds Directive. We examined the key environmental characteristics that determine the possibility of GHW occurrence in vast forests in northeast Poland. Woodpeckers were inventoried in spring on 54 study plots (4 km2) covering 20% of the forest area. Active territories were detected and mapped using the playback experiment of territorial voices and drumming. The generalized linear model GLM, random forest RF, and Boosting were used for modeling. GLM was used to indicate the most critical factors affecting the abundance of GHW. The number of territories in a single study plot ranged from 0 to 3; the most frequent were areas without woodpeckers. The probability of the nesting of the GHW was increasing at plots with watercourses, a bigger share of mixed forest area, and a proportion of stands over 120 years old. The calculation for all 400 quadrats allowed us to estimate the population size at approximately 180–200 breeding pairs. The overall density of GHW in the study area was assessed at 0.13/km2, while at the optimal quadrats, it increased to about 0.75/km2. Preference for watercourses was linked to alders growing along water banks. Near the water, there are often small meadows where the GHW can prey on ants. In turn, old-growth forests above 120 years old increased the probability of the presence of the GHW. There are more dead and dying trees in older forests, which are the ones the GHW chooses to excavate cavities. To effectively protect the habitats of the GHW, it is necessary to maintain a larger area of stands over 120 years old, mainly on wet sites.

Land Use Effects on the Space Use and Dispersal of an Apex Predator in an Ecotone Between Tropical Biodiversity Hotspots

2025-06-19

Bernardo Brandão Niebuhr , Sandra M. C. Cavalcanti , Ermeson A. Vilalba +7 more | Diversity

Assessing the ranging and dispersal behavior of apex predators and its consequences for landscape connectivity is of paramount importance for understanding population and ecosystem effects of anthropogenic land use change. … Assessing the ranging and dispersal behavior of apex predators and its consequences for landscape connectivity is of paramount importance for understanding population and ecosystem effects of anthropogenic land use change. Here, we synthesize ranging and dispersal ecological information on pumas (Puma concolor) and present estimates of how different land uses affect the space use and dispersal of pumas on fragmented landscapes in an ecotone between biodiversity hotspots in southeastern Brazil. Additionally, we evaluate the effect of animal translocations on dispersal and movement patterns. Using location data for 14 GPS-collared pumas and land use data, we assessed when, how long, and how far individuals dispersed; how forest loss and infrastructure influenced puma home range size; and how movement patterns changed according to land use and proximity to infrastructure, during ranging and dispersal, for residents, natural dispersers, and translocated individuals. We present the first detailed record on the dispersal of pumas in Brazil and in the tropics, including long-distance dispersals, and show that pumas moved faster and more linearly during dispersal than during ranging. Their movement was slower and their home ranges were smaller in more forested areas, underscoring the importance of forest as habitat. In contrast, movement rates were higher in open pastures, mainly during dispersal. Our study underscores the scarcity of research on puma space use and dispersal in South America and reveals partial divergences in dispersal behaviors compared to North America and temperate regions, especially concerning dispersal ages. Furthermore, we give the first steps in presenting how land cover and human infrastructure affect the movement of this apex predator in a tropical ecosystem, an important subsidy for land use management. We call for more comprehensive studies on the movement ecology of carnivores combined with long-term population monitoring, to allow linking individual behavior with metapopulation dynamics and landscape connectivity and drawing more effective measures to sustain their populations.

Assessing sampling error associated with animal movements and distributions across drone monitoring strategies

2025-06-19

Emma A. Schultz , Natasha Ellison , Landon R. Jones +2 more | Ecological Modelling

Late Quaternary population expansion in gray brocket deer [Subulo gouazoubira (G. Fisher, 1814), Cervidae, Mammalia] in Brazil

2025-06-19

Alex Hubbe , Mark Hübbe , Elver Luiz Mayer +7 more | Journal of Quaternary Science

ABSTRACT There is little information about the changes in the abundance of mammalian species in South America during the late Quaternary, which is a key parameter to understanding past ecological … ABSTRACT There is little information about the changes in the abundance of mammalian species in South America during the late Quaternary, which is a key parameter to understanding past ecological and evolutionary dynamics. Here, we describe a conspicuous increase in the abundance of the gray brocket deer ( Subulo gouazoubira G. Fisher, 1814; Mammalia) during the late Quaternary in Brazil based on paleontological evidence. We studied the material retrieved from pitfall deposits in Cuvieri Cave (Brazil) representing three time intervals (Late Pleistocene, Pleistocene/Holocene transition, and Holocene). The deposits in this cave were previously characterized in terms of facies composition, chronology, and overall taxa and taphonomy. We combined previous data with taxonomic identification at the species level for deer (morphological and ancient DNA analyses), quantification of the number of individuals for large mammals (>10 kg), taphonomic analyses, and stratigraphic distribution of specimens. Our results show that while in the Late Pleistocene gray brocket deer corresponded to up to 18% of 38 individuals, in the Holocene they represented at least 82% of 78 individuals. We interpret this change in frequency as a considerable increase in abundance in the surroundings of the cave, after excluding major taphonomical biases. The causes for this phenomenon are uncertain but could have involved a surplus of food availability and predation release due to the late Quaternary extinction event.

Bears in North America: Habitats, hunting, and politics

2025-06-19

Mark S. Boyce , Andrew E. Derocher | Journal of Wildlife Management

Abstract Populations of all 3 of North America's bear species have increased during the past 50 years, attributable to reduced persecution and improved management. Some actions consistent with the North … Abstract Populations of all 3 of North America's bear species have increased during the past 50 years, attributable to reduced persecution and improved management. Some actions consistent with the North American Model of Wildlife Conservation can explain these population increases, although conservation practices vary substantially among jurisdictions and species. Most management and conservation of North America's bear species is by state, provincial, or territorial agencies. However, federal engagement has occurred for grizzly bears ( Ursus arctos ), polar bears ( U. maritimus ), and some black bear ( U. americanus ) populations. Harvest has been the primary tool that agencies have used to manage bear populations. Increased focus on managing habitats and mitigating human–bear conflicts will help to ensure the long‐term success of bear management in North America.

Depredación de Nasuella olivacea (Carnivora: Procyonidae) por Tremarctos ornatus (Carnivora: Ursidae) y Canis lupus familiaris (Carnivora: Canidae), en Parque Chingaza, Colombia

2025-06-19

Fredy Yhamit García Pulido , Pedro A. Camargo‐Martínez , Oscar G. Raigozo Hortúa +1 more | Mammalogy Notes

El Cusumbo de montaña (Nasuella olivacea) es una especie de gran importancia para los ecosistemas andinos, debido a que dispersa semillas y ayuda a controlar poblaciones de invertebrados y pequeños … El Cusumbo de montaña (Nasuella olivacea) es una especie de gran importancia para los ecosistemas andinos, debido a que dispersa semillas y ayuda a controlar poblaciones de invertebrados y pequeños vertebrados. De igual forma, N. olivacea puede hacer parte de la dieta de mamíferos grandes como el Oso andino (Tremarctos ornatus) y el Puma (Puma concolor). Sin embargo, la presencia de perros domésticos (Canis lupus familiaris) categorizados como perros sueltos, perros callejeros y perros ferales pueden generar impactos en las dinámicas poblacionales de la fauna silvestre y en los procesos ecológicos de los bosques y páramos. En esta nota reportamos el primer consumo de Cusumbo de montaña por Oso andino y por Perro doméstico en el Parque Nacional Natural Chingaza, Colombia.

Predicting biodiversity loss in terrestrial vertebrates: A global analysis of red list index trends and key drivers (2002–2021)

2025-06-19

Amy Rogers | Biological Conservation

A Steep Decline in Passerines Ringed Over Half a Century at Punta Entinas-Sabinar, Spain, a Strategic Western Palearctic Migration Locality

2025-06-19

Mariano Paracuellos , José Manuel Cid Díaz , José Antonio Oña +3 more | Ardeola

Sink or Swim: Mortality Rates of Small Mammals from Two Swimming Pools in Virginia and Pennsylvania

2025-06-19

Neal Woodman , Bruce B. Collette | Northeastern Naturalist

Landscape connectivity without governance? Exploring wildlife presence and corridor influence in urbanizing Carpathian Areas

2025-06-19

Tudor Radu , Ileana Pătru-Stupariu , Mihai Mustățea +2 more | Research Square (Research Square)

<title>Abstract</title> Enhancing landscape connectivity is essential for facilitating wildlife movement, supporting habitat restoration, and maintaining ecological functionality. However, such improvements may inadvertently increase the frequency of human–wildlife interactions (HWIs), particularly … <title>Abstract</title> Enhancing landscape connectivity is essential for facilitating wildlife movement, supporting habitat restoration, and maintaining ecological functionality. However, such improvements may inadvertently increase the frequency of human–wildlife interactions (HWIs), particularly in areas where ecological corridors intersect with human settlements. This dynamic is exemplified in Romania’s Prahova Valley, a region within the Carpathian Mountains where large protected areas inhabited by species such as the brown bear (<italic>Ursus arctos</italic>), grey wolf (<italic>Canis lupus</italic>), and wild boar (<italic>Sus scrofa</italic>) are adjacent to major tourist towns. In recent decades, both residents and tourists have reported a notable rise in HWIs. Although ecological corridors have been conceptually integrated into Romanian legislation, no formal implementation or regulation has been realized to date. In the Prahova Valley, preliminary studies have proposed potential habitat linkages, but their impact remains unverified. This study examines the hypothesis that these proposed corridors contribute to increasing wildlife presence in human-dominated areas. Using stakeholder interviews, spatial analysis of corridor data, and GIS tools, we analyse the relationship between corridor proximity and HWI patterns. Despite their unofficial status, these corridors may provide a useful framework for future ecological planning. Our findings underscore the importance of assessing HWI risks prior to corridor formalization and highlight the influence of adjacent protected areas in shaping human–wildlife dynamics under ongoing urban expansion.

Plumage maturation, molt, and morphology of the critically endangered Hooded Grebe (Podiceps gallardoi)

2025-06-18

Ignacio Roesler , Laura Fasola , Juan Klavins +7 more | El Hornero

The understanding of morphological and behavioral aspects of bird species can guide appropriate management actions for their conservation. Grebes (Podicipedidae) are peculiar in their molting strategy, since body feathers are … The understanding of morphological and behavioral aspects of bird species can guide appropriate management actions for their conservation. Grebes (Podicipedidae) are peculiar in their molting strategy, since body feathers are continuously replaced during the whole year. Available information about natural history of Neotropical grebes is scattered. The Hooded Grebe (Podiceps gallardoi) is a critically endangered species with a global population of less than 800 individuals that inhabits the remote highlands plateaus of Austral Patagonia. In this work we present information about sexual differences in molting behavior, plumage coloration and morphological characteristics of this species. During seven years we monitored the whole population of Hooded Grebe and collected data from field observations and from collected individuals that had been killed by American mink. Our results show sexual differences in morphology, and in timing of molting, but not in coloration in the UV and visible range. Hooded Grebe’s molting strategy differs from that of other grebes, including closely related species, as it lacks molting migration and does not develop a visibly different alternate winter plumage. Molting strategies and morphological differences between sexes may represent adaptations to variable conditions in extreme environments of southern Patagonia.

Estimating abundance of harvested populations at the management unit scale

2025-06-18

Allison C. Keever , James D. Kelly , Garrett B. Clevinger +1 more | PLoS ONE

Management of harvested populations relies on accurate assessment of abundance within management units to reevaluate and set harvest regulations. Several statistical approaches use readily available age-at-harvest data to estimate populations, … Management of harvested populations relies on accurate assessment of abundance within management units to reevaluate and set harvest regulations. Several statistical approaches use readily available age-at-harvest data to estimate populations, but these often rely on auxiliary data which can be costly to collect and may not provide reliable estimates at the management unit scale. We developed a Bayesian integrated population model (IPM) relying solely on available harvest data to estimate abundance of white-tailed deer in Tennessee where estimates of abundance were lacking. We fit the IPM to reported harvest data and estimates of total harvest from hunter surveys to estimate abundance statewide and within deer management units (DMUs). Statewide deer harvest in Tennessee from 2005 to 2023 ranged between 132,256 and 181,477 deer annually (mean = 160,050; SD = 16,178). Although the population fluctuated, median population growth rate was 0.99 (90% CRI 0.978–1.003) during the study. Statewide population abundance was estimated at 890,657 (90% CRI 786,627–1,172,514) deer in 2023. Our IPM provided a comprehensive picture of deer population dynamics and allowed us to estimate abundance and demographic rates using only harvest data and informative priors. This model demonstrates the benefits of using informative priors and regularizing parameters in ecological studies. The IPM is a useful, flexible tool to monitor harvested populations at finer spatial scales thereby allowing decisions on harvest regulations to be based on precise estimates of abundance within specific management units.

Arrival, rise, fall, and again rise of the Asiatic lion Panthera leo leo in India

2025-06-18

Hari Singh | Journal of Wildlife Science.

Many animal populations have shifted their distribution and emigrated to new areas in response to climate change, and lions in India have had a similar story. This commentary examines historical … Many animal populations have shifted their distribution and emigrated to new areas in response to climate change, and lions in India have had a similar story. This commentary examines historical records, environmental barriers, climate change in the region of Indus-Sarasvati rivers that created conditions for lions’s entry in India. Recovery of artefacts of several wild animals and near absence of lion in these ancient artworks at any site of the Indus-Sarasvati civilization revealed that lion was absent or rare beyond the east of the Indus River in India before 2000 BCE. Environment progressed from the moist conditions to dry in the Indus-Sarasvati region between 2600 and 1500 BCE, discharge of snow water from the Himalayas declined and many large rivers of Indus-Sarasvati system transformed into seasonal rivers. Also, the dense forests transformed to thorn forests and savannah like vegetation over a period after 2000 BCE. Subsequently, Asiatic lions from the ancient Persian land got suitable environment and opportunity to cross the Indus valley to the east. After a period, lion population flourished reaching its peak in India during Buddha-Mauryan-Gupta period (600 BCE – 500 AD). Hunting records revealed that the distribution and abundance of lions remained at its peak during the Mughal and early British period before end of the Little Ice Age during the mid-19th century. Subsequently, fall of the Asiatic lion was sharp as numbers declined below hundred. After a long critical period of ups and downs, Asiatic lion’s number and distribution range is on consistent rise since declaration of Gir Lion Sanctuary Project in the early 1970s. Since then, lion population has increased by five folds (891 individuals in 2025) along with impressive recovery of wild ungulate population, turning management approach into one of the most successful wildlife conservation stories in the world. Considering dispersion trend of the lions and their arrival to Barda forest, an identified alternative site for lion, Gujarat Government has prepared a long term comprehensive project, “The Project Lion @2047-A vision of Amrut Kal” to secure and manage the growing lion population and its potential habitats distributed in entire Saurashtra region.

Pack size, home range size and activity pattern of dhole (Cuon alpinus) in Mudumalai Tiger Reserve, India: effects of anthropogenic environment use and reproduction

2025-06-18

Shuta Sawaguri , Raman Sukumar , Shiro Kohshima | Research Square (Research Square)

<title>Abstract</title> Understanding the ecology of endangered dhole and their responses to anthropogenic environments is important for mitigating conflicts with humans and ensuring conservation efforts for this species. This study investigated … <title>Abstract</title> Understanding the ecology of endangered dhole and their responses to anthropogenic environments is important for mitigating conflicts with humans and ensuring conservation efforts for this species. This study investigated the pack size, home range size, reproduction and activity pattern of multiple dhole packs in Mudumalai Tiger Reserve, southern India, from September 2011 to August 2015 using direct observation and camera trapping. The findings were compared across dhole packs to assess the influence of reproduction and human-modified environments on their ecology and behaviour. Of the five packs identified (P1–P5), reproduction was observed three times in two packs (P1, P2) with an average litter size of seven and denning between December and February, while the others likely did not reproduce. Group sizes observed outside the den area (mean: 6.6 ± 3.4) decreased from November to December, likely due to pup dispersal and den defense needs. Packs inhabiting the areas with high proportion of anthropogenic environments and feeding on livestock and garbage (P1, P2) had significantly smaller home ranges (7.0–14.4 km²) compared to those in more natural environments (P3, P4: 36.1–40.3 km²), suggesting higher foraging efficiency in human-modified landscapes. The dholes in the study area were primarily diurnal, with 74.4% of activity occurring during daylight hours. They were particularly active in the morning and evening as they frequently took very long rests over six hours during midday. However, the pack with the greatest use of anthropogenic environments (P2) showed cathemeral activity pattern increasing night activity up to 50.5%, probably to avoid encounters with humans. The high mortality of pups estimated in P2 and unnatural deaths of adults observed both in P1 and P2 suggest that the nutritional benefits and increased reproduction in anthropogenic environments could be offset by the higher mortality rates, potentially due to conflicts with humans and diseases transmitted by feral or domestic dogs.