Biochemistry, Genetics and Molecular Biology › Developmental Biology

Animal Vocal Communication and Behavior

Works Count: 34548

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Description

This cluster of papers explores avian vocal communication, including the neural pathways underlying vocal control, the impact of urban noise on birdsong, the evolutionary implications of bird vocalizations, and the role of social learning in avian communication. It also delves into the genomic aspects of songbirds and the effects of noise pollution on avian communities.

Keywords

Avian Vocal Communication; Birdsong; Neural Pathways; Acoustic Communication; Noise Impact; Vocal Learning; Songbird Genome; Social Learning; Urban Noise; Evolutionary Biology

Acoustic Communication in Noise

2005-01-01

Henrik Brumm , Hans Slabbekoorn

Avian brains and a new understanding of vertebrate brain evolution

2005-02-01

Erich D. Jarvis , Onur Güntürkün , Laura L. Bruce +7 more

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Bird song: biological themes and variations

1996-01-01

Clive K. Catchpole , Peter J. B. Slater

Introduction 1. The study of bird song 2. Production and perception 3. How song develops 4. Getting the message across 5. When do birds sing? 6. Recognition and territorial defence … Introduction 1. The study of bird song 2. Production and perception 3. How song develops 4. Getting the message across 5. When do birds sing? 6. Recognition and territorial defence 7. Sexual selection and female choice 8. Themes and variations 9. Variation in time and space List of common and scientific names References Index.

Auditory Scene Analysis

2008-01-01

Albert S. Bregman

Correlated evolution of morphology and vocal signal structure in Darwin's finches

2001-01-01

Jeffrey Podos

Sound transmission and its significance for animal vocalization

1977-09-01

Ken Marten , Peter Marler

The Role of Auditory Feedback in the Control of Vocalization in the White-Crowned Sparrow1

1965-01-12

Masakazu Konishi

Neural Basis of Rhythmic Behavior in Animals

1980-10-31

Fred Delcomyn

Timing of the repetitive movements that constitute any rhythmic behavior is regulated by intrinsic properties of the central nervous system rather than by sensory feedback from moving parts of the … Timing of the repetitive movements that constitute any rhythmic behavior is regulated by intrinsic properties of the central nervous system rather than by sensory feedback from moving parts of the body. Evidence of this permits resolution of the long-standing controversy over the neural basis of rhythmic behavior and aids in the identification of this mechanism as a general principle of neural organization applicable to all animals with central nervous systems.

A comparative approach to vocal learning: Song development in white-crowned sparrows.

1970-05-01

Peter Marler

Forebrain Lesions Disrupt Development But Not Maintenance of Song in Passerine Birds

1984-05-25

Sarah W. Bottjer , Elizabeth A. Miesner , Arthur P. Arnold

The magnocellular nucleus of the anterior neostriatum is a forebrain nucleus of passerine birds that accumulates testosterone and makes monosynaptic connections with other telencephalic nuclei that control song production in … The magnocellular nucleus of the anterior neostriatum is a forebrain nucleus of passerine birds that accumulates testosterone and makes monosynaptic connections with other telencephalic nuclei that control song production in adult birds. Lesions in the magnocellular nucleus disrupted song development in juvenile male zebra finches but did not affect maintenance of stable song patterns by adult birds. These results represent an instance in which lesions of a discrete brain region during only a restricted phase in the development of a learned behavior cause permanent impairment. Because cells of the magnocellular nucleus accumulate androgens these findings raise the possibility that this learning is mediated by hormones.

The genome of a songbird

2010-03-30

Wesley C. Warren , David F. Clayton , Hans Ellegren +7 more

The genome of the zebra finch — a songbird and a model for the study of vertebrate brain, behaviour and evolution — has been sequenced. Its comparison with the chicken … The genome of the zebra finch — a songbird and a model for the study of vertebrate brain, behaviour and evolution — has been sequenced. Its comparison with the chicken genome, the only other bird genome available, shows that genes with neural function and implicated in cognitive processing of song have been rapidly evolving in the finch lineage. The study also shows that vocal communication engages much of the zebra finch brain transcriptome and identifies a potential integrator of microRNA signals linked to vocal communication. The genome of the zebra finch — a songbird and a model for studying the vertebrate brain, behaviour and evolution — has been sequenced. Comparison with the chicken genome, the only other bird genome available, shows that genes that have neural function and are implicated in the cognitive processing of song have been evolving rapidly in the finch lineage. Moreover, vocal communication engages much of the transcriptome of the zebra finch brain. The zebra finch is an important model organism in several fields1,2 with unique relevance to human neuroscience3,4. Like other songbirds, the zebra finch communicates through learned vocalizations, an ability otherwise documented only in humans and a few other animals and lacking in the chicken5—the only bird with a sequenced genome until now6. Here we present a structural, functional and comparative analysis of the genome sequence of the zebra finch (Taeniopygia guttata), which is a songbird belonging to the large avian order Passeriformes7. We find that the overall structures of the genomes are similar in zebra finch and chicken, but they differ in many intrachromosomal rearrangements, lineage-specific gene family expansions, the number of long-terminal-repeat-based retrotransposons, and mechanisms of sex chromosome dosage compensation. We show that song behaviour engages gene regulatory networks in the zebra finch brain, altering the expression of long non-coding RNAs, microRNAs, transcription factors and their targets. We also show evidence for rapid molecular evolution in the songbird lineage of genes that are regulated during song experience. These results indicate an active involvement of the genome in neural processes underlying vocal communication and identify potential genetic substrates for the evolution and regulation of this behaviour.

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Principles of Animal Communication

1999-01-01

Ralph W. Howard

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Recognizing friends by their walk: Gait perception without familiarity cues

1977-05-01

James E. Cutting , Lynn T. Kozlowski

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Physical constraints on acoustic communication in the atmosphere: Implications for the evolution of animal vocalizations

1978-01-01

R. Haven Wiley , Douglas G. Richards

An ultra-sparse code underliesthe generation of neural sequences in a songbird

2002-09-05

Richard H. R. Hahnloser , Alexay A. Kozhevnikov , Michale S. Fee

Neuronal production, migration, and differentiation in a vocal control nucleus of the adult female canary brain.

1983-04-01

Steven A. Goldman , Fernando Nottebohm

The vocal control nucleus designated HVc (hyperstriatum ventrale, pars caudalis) of adult female canaries expands in response to systemic testosterone administration, which also induces the females to sing in a … The vocal control nucleus designated HVc (hyperstriatum ventrale, pars caudalis) of adult female canaries expands in response to systemic testosterone administration, which also induces the females to sing in a male-like manner. We became interested in the possibility of neurogenesis as a potential basis for this phenomenon. Intact adult female canaries were injected with [3H]thymidine over a 2-day period. Some birds were given testosterone implants at various times before thymidine. The birds were sacrificed 5 wk after hormone implantation, and their brains were processed for autoradiography. In parallel control experiments, some birds were given implants of cholesterol instead of testosterone. All birds showed considerable numbers of labeled neurons, glia, endothelia, and ventricular zone cells in and around HVc. Ultrastructural analysis confirmed the identity of these labeled neurons. Cholesterol- and testosterone-treated birds had similar neuronal labeling indices, which ranged from 1.8% to 4.0% in HVc. Thus, neurogenesis occurred in these adults independently of exogenous hormone treatment. Conversely, both glial and endothelial proliferation rates were markedly stimulated by exogenous testosterone treatment. We determined the origin of the thymidine-incorporating neurons by sacrificing two thymidine-treated females soon after their thymidine injections, precluding any significant migration of newly labeled cells. Analysis of these brains revealed no cells of neuronal morphology present in HVc but a very heavily labeled ventricular zone overlying HVc. We conclude that neuronal precursors exist in the HVc ventricular zone that incorporate tritiated thymidine during the S phase preceding their mitosis; after division these cells migrate into, and to some extent beyond, HVc. This ventricular zone neurogenesis seems to be a normally occurring phenomenon in intact adult female canaries.

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Monkey Responses to Three Different Alarm Calls: Evidence of Predator Classification and Semantic Communication

1980-11-14

Robert M. Seyfarth , Dorothy L. Cheney , Peter Marler

Vervet monkeys give different alarm calls to different predators. Recordings of the alarms played back when predators were absent caused the monkeys to run into trees for leopard alarms, look … Vervet monkeys give different alarm calls to different predators. Recordings of the alarms played back when predators were absent caused the monkeys to run into trees for leopard alarms, look up for eagle alarms, and look down for snake alarms. Adults call primarily to leopards, martial eagles, and pythons, but infants give leopard alarms to various mammals, eagle alarms to many birds, and snake alarms to various snakelike objects. Predator classification improves with age and experience.

Vocal affect expression: A review and a model for future research.

1986-01-01

Klaus R. Scherer

In reviewing the literature on the vocal expression of emotion, a discrepancy between reported high accuracy in vocal-auditory recognition and the lack of clear evidence for the acoustic differentiation of … In reviewing the literature on the vocal expression of emotion, a discrepancy between reported high accuracy in vocal-auditory recognition and the lack of clear evidence for the acoustic differentiation of vocal expression is noted. The latter is explained by (a) a paucity of research on voice quality, (b) neglect of the social signaling functions of affect vocalization, and (c) insufficiently precise conceptualization of the underlying emotional states. A component patterning model of vocal affect expression is proposed that attempts to rink the outcomes of antecedent event evaluation to biologically based response patterns. On the basis of a literature survey of acoustic-phonetic evidence, the likely phonatory and articulatory correlates of the physiological responses characterizing different emotional states are described in the form of three major voice types (narrow-wide, lax-tense, full-thin). Specific predictions are made as to the changes in acoustic parameters resulting from changing voice types. These predictions are compared with the pattern of empirical findings yielded by a comprehensive survey of the literature on vocal cues in emotional expression. Although the comparison is largely limited to the tense-lax voice type (because acoustic parameters relevant to the other voice types have not yet been systematically studied), a high degree of convergence is revealed. It is suggested that the model may help to stimulate hypothesis-guided research as well as provide a framework for the development of appropriate research paradigms.

Speech Perception by the Chinchilla: Voiced-Voiceless Distinction in Alveolar Plosive Consonants

1975-10-03

Patricia K. Kuhl , James D. Miller

Four chinchillas were trained to respond differently to /t/ and /d/ consonant-vowel syllables produced by four talkers in three vowel contexts. This training generalized to novel instances, including synthetically produced … Four chinchillas were trained to respond differently to /t/ and /d/ consonant-vowel syllables produced by four talkers in three vowel contexts. This training generalized to novel instances, including synthetically produced /da/ and /ta/ (voice-onset times of 0 and +80 milliseconds, respectively). In a second experiment, synthetic stimuli with voice-onset times between 0 and +80 milliseconds were presented for identification. The form of the labeling functions and the "phonetic boundaries" for chinchillas and English-speaking adults were similar.

Ecological Sources of Selection on Avian Sounds

1975-01-01

Eugene S. Morton

This study describes selection derived from habitat acoustics on the physical structure of avian sounds. Sound propagation tests were made in forest, edge, and grassland habitats in Panama to quantify … This study describes selection derived from habitat acoustics on the physical structure of avian sounds. Sound propagation tests were made in forest, edge, and grassland habitats in Panama to quantify pure tone and random noise band sound transmission levels. The sounds of bird species in each habitat were analyzed to determine the emphasized frequency, frequency range, and sound type (whether pure tonelike or highly modulated). Forest habitats differ from grass and edge in that a narrow range of frequencies (1,585-2,500 Hz) has lower sound attenuation than lower or higher frequencies. Attenuation increases rapidly above 2,500 Hz. Bird sounds from species occurring at the lower forest levels were found to be predominantly pure tonelike with a frequency emphasized averaging 2,200 Hz, conforming to the predictions based on sound propagation tests. The edge habitat is characterized by a wide range of frequencies having a generally similar attenuation rate. Pure tone and random noise band sounds did not differ in attenuation rates. The sounds of edge birds have high variance in the frequency-emphasized component, and more are composed of both modulated and pure tone elements to a greater extent than forest or grassland species. It is suggested that this variance is a reflection of a relative lack of selection pressure from habitat acoustics. Grassland propagation tests showed a positive correlation between increasing frequency and increasing attenuation. It is hypothesized that information transfer may be based on temporal aspects of the signal since these are less distorted in temperature- and wind-speed-stratified open environments.

Receiver psychology and the evolution of multicomponent signals

1999-11-01

Candy Rowe

On the Occurrence and Significance of Motivation-Structural Rules in Some Bird and Mammal Sounds

1977-09-01

Eugene S. Morton

The convergent use of harsh, low-frequency sounds by hostile animals and more pure tonelike, high frequency sounds by fearful or appeasing animals is discussed in an evolutionary context. It is … The convergent use of harsh, low-frequency sounds by hostile animals and more pure tonelike, high frequency sounds by fearful or appeasing animals is discussed in an evolutionary context. It is proposed that many sounds in species' repertoires are evolved from motivation-structural rules derived from selection pressures favoring the use of communication instead of, or in conjunction with, fighting to attain resources. The use of this concept should further the appreciation of the relationship between sound structure and function.

Vervet monkey alarm calls: Semantic communication in a free-ranging primate

1980-11-01

Robert M. Seyfarth , Dorothy L. Cheney , Peter Marler

Joint music making promotes prosocial behavior in 4-year-old children☆☆☆

2010-07-09

Sebastian Kirschner , Michael Tomasello

Sexual Dimorphism in Vocal Control Areas of the Songbird Brain

1976-10-08

Fernando Nottebohm , Arthur P. Arnold

In canaries and zebra finches, three vocal control areas in the brain are strikingly larger in males than in females. A fourth, area X of the lobus parolfactorius, is well … In canaries and zebra finches, three vocal control areas in the brain are strikingly larger in males than in females. A fourth, area X of the lobus parolfactorius, is well developed in males of both species, less well developed in female canaries, and absent or not recognizable in female zebra finches. These size differences correlate well with differences in singing behavior. Males of both species learn song by reference to auditory information, and females do not normally sing. Exogenous testosterone induces singing in female canaries but not in female zebra finches. This is believed to be the first report of such gross sexual dimorphism in a vertebrate brain.

Ecology and Evolution of Acoustic Communication in Birds.

1997-07-01

Douglas A. Nelson , Donald E. Kroodsma , Edward H. Miller

Twenty-five invited papers reviewing the contributing ornithologists' current research in birds' acoustic communication with an ecological and evolutionary focus, and also identifying the areas they feel will dominate future research … Twenty-five invited papers reviewing the contributing ornithologists' current research in birds' acoustic communication with an ecological and evolutionary focus, and also identifying the areas they feel will dominate future research efforts. The discussions center around the areas of vocal developm

Birds sing at a higher pitch in urban noise

2003-07-01

Hans Slabbekoorn , Margriet Peet

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Signals, Signal Conditions, and the Direction of Evolution

1992-03-01

John A. Endler

There is a bewildering diversity of signals, sensory systems, and signaling behavior. A consideration of how these traits affect each other's evolution explains some of this diversity. Natural selection favors … There is a bewildering diversity of signals, sensory systems, and signaling behavior. A consideration of how these traits affect each other's evolution explains some of this diversity. Natural selection favors signals, receptors, and signaling behavior that maximize the received signals relative to background noise and minimize signal degradation. Properties of sensory systems bias the direction of evolution of the signals that they receive. For example, females may prefer males whose signals they can perceive more easily, and this will lead to the spread of more easily perceived male traits. Environmental conditions during signal transmission and detection also affect signal perception. Specific environmental conditions will bias the evolutionary direction of behavior, which affects the time and place of signaling as well as microhabitat preferences. Increased specialization of microhabitats and signaling behavior may lead to biased evolution of the sensory systems to work more efficiently. Thus, sensory systems, signals, signaling behavior, and habitat choice are evolutionarily coupled. These suites of traits should coevolve in predictable directions, determined by environmental biophysics, neurobiology, and the genetics of the suites of traits--hence the term "sensory drive." Because conditions vary in space and time, diversity will be generated

A Brain for All Seasons: Cyclical Anatomical Changes in Song Control Nuclei of the Canary Brain

1981-12-18

Fernando Nottebohm

Male canaries that have reached sexual maturity can, in subsequent years, learn new song repertoires. Two telencephalic song control nuclei, the hyperstriatum ventrale, pars caudale, and nucleus robustus archistriatalis are, … Male canaries that have reached sexual maturity can, in subsequent years, learn new song repertoires. Two telencephalic song control nuclei, the hyperstriatum ventrale, pars caudale, and nucleus robustus archistriatalis are, respectively, 99 and 76 percent larger in the spring, when male canaries are producing stable adult song, than in the fall, at the end of the molt and after several months of not singing. It is hypothesized that such fluctuations reflect an increase and then reduction in numbers of synapses and are related to the yearly ability to acquire new motor coordinations.

Characterization of a novel protein regulated during the critical period for song learning in the zebra finch

1995-08-01

Julia M. George , Hui Jin , Wendy S. Woods +1 more

Revised nomenclature for avian telencephalon and some related brainstem nuclei

2004-04-22

Anton Reiner , David J. Perkel , Laura L. Bruce +7 more

Abstract The standard nomenclature that has been used for many telencephalic and related brainstem structures in birds is based on flawed assumptions of homology to mammals. In particular, the outdated … Abstract The standard nomenclature that has been used for many telencephalic and related brainstem structures in birds is based on flawed assumptions of homology to mammals. In particular, the outdated terminology implies that most of the avian telencephalon is a hypertrophied basal ganglia, when it is now clear that most of the avian telencephalon is neurochemically, hodologically, and functionally comparable to the mammalian neocortex, claustrum, and pallial amygdala (all of which derive from the pallial sector of the developing telencephalon). Recognizing that this promotes misunderstanding of the functional organization of avian brains and their evolutionary relationship to mammalian brains, avian brain specialists began discussions to rectify this problem, culminating in the Avian Brain Nomenclature Forum held at Duke University in July 2002, which approved a new terminology for avian telencephalon and some allied brainstem cell groups. Details of this new terminology are presented here, as is a rationale for each name change and evidence for any homologies implied by the new names. Revisions for the brainstem focused on vocal control, catecholaminergic, cholinergic, and basal ganglia‐related nuclei. For example, the Forum recognized that the hypoglossal nucleus had been incorrectly identified as the nucleus intermedius in the Karten and Hodos ( 1967 ) pigeon brain atlas, and what was identified as the hypoglossal nucleus in that atlas should instead be called the supraspinal nucleus. The locus ceruleus of this and other avian atlases was noted to consist of a caudal noradrenergic part homologous to the mammalian locus coeruleus and a rostral region corresponding to the mammalian A8 dopaminergic cell group. The midbrain dopaminergic cell group in birds known as the nucleus tegmenti pedunculopontinus pars compacta was recognized as homologous to the mammalian substantia nigra pars compacta and was renamed accordingly; a group of γ‐aminobutyric acid (GABA)ergic neurons at the lateral edge of this region was identified as homologous to the mammalian substantia nigra pars reticulata and was also renamed accordingly. A field of cholinergic neurons in the rostral avian hindbrain was named the nucleus pedunculopontinus tegmenti, whereas the anterior nucleus of the ansa lenticularis in the avian diencephalon was renamed the subthalamic nucleus, both for their evident mammalian homologues. For the basal (i.e., subpallial) telencephalon, the actual parts of the basal ganglia were given names reflecting their now evident homologues. For example, the lobus parolfactorius and paleostriatum augmentatum were acknowledged to make up the dorsal subdivision of the striatal part of the basal ganglia and were renamed as the medial and lateral striatum. The paleostriatum primitivum was recognized as homologous to the mammalian globus pallidus and renamed as such. Additionally, the rostroventral part of what was called the lobus parolfactorius was acknowledged as comparable to the mammalian nucleus accumbens, which, together with the olfactory tubercle, was noted to be part of the ventral striatum in birds. A ventral pallidum, a basal cholinergic cell group, and medial and lateral bed nuclei of the stria terminalis were also recognized. The dorsal (i.e., pallial) telencephalic regions that had been erroneously named to reflect presumed homology to striatal parts of mammalian basal ganglia were renamed as part of the pallium, using prefixes that retain most established abbreviations, to maintain continuity with the outdated nomenclature. We concluded, however, that one‐to‐one (i.e., discrete) homologies with mammals are still uncertain for most of the telencephalic pallium in birds and thus the new pallial terminology is largely devoid of assumptions of one‐to‐one homologies with mammals. The sectors of the hyperstriatum composing the Wulst (i.e., the hyperstriatum accessorium intermedium, and dorsale), the hyperstriatum ventrale, the neostriatum, and the archistriatum have been renamed (respectively) the hyperpallium (hypertrophied pallium), the mesopallium (middle pallium), the nidopallium (nest pallium), and the arcopallium (arched pallium). The posterior part of the archistriatum has been renamed the posterior pallial amygdala, the nucleus taeniae recognized as part of the avian amygdala, and a region inferior to the posterior paleostriatum primitivum included as a subpallial part of the avian amygdala. The names of some of the laminae and fiber tracts were also changed to reflect current understanding of the location of pallial and subpallial sectors of the avian telencephalon. Notably, the lamina medularis dorsalis has been renamed the pallial‐subpallial lamina. We urge all to use this new terminology, because we believe it will promote better communication among neuroscientists. Further information is available at http://avianbrain.org . J. Comp. Neurol. 473:377–414, 2004. © 2004 Wiley‐Liss, Inc.

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A procedure for an automated measurement of song similarity

2000-06-01

Ofer Tchernichovski , Fernando Nottebohm , Ching Elizabeth Ho +2 more

Communication of emotions in vocal expression and music performance: Different channels, same code?

2003-01-01

Patrik N. Juslin , Petri Laukka

Many authors have speculated about a close relationship between vocal expression of emotions and musical expression of emotions. but evidence bearing on this relationship has unfortunately been lacking. This review … Many authors have speculated about a close relationship between vocal expression of emotions and musical expression of emotions. but evidence bearing on this relationship has unfortunately been lacking. This review of 104 studies of vocal expression and 41 studies of music performance reveals similarities between the 2 channels concerning (a) the accuracy with which discrete emotions were communicated to listeners and (b) the emotion-specific patterns of acoustic cues used to communicate each emotion. The patterns are generally consistent with K. R. Scherer's (1986) theoretical predictions. The results can explain why music is perceived as expressive of emotion, and they are consistent with an evolutionary perspective on vocal expression of emotions. Discussion focuses on theoretical accounts and directions for future research.

Perceived Predation Risk Reduces the Number of Offspring Songbirds Produce per Year

2011-12-08

Liana Zanette , Aija F. White , Marek C. Allen +1 more

Predator effects on prey demography have traditionally been ascribed solely to direct killing in studies of population ecology and wildlife management. Predators also affect the prey's perception of predation risk, … Predator effects on prey demography have traditionally been ascribed solely to direct killing in studies of population ecology and wildlife management. Predators also affect the prey's perception of predation risk, but this has not been thought to meaningfully affect prey demography. We isolated the effects of perceived predation risk in a free-living population of song sparrows by actively eliminating direct predation and used playbacks of predator calls and sounds to manipulate perceived risk. We found that the perception of predation risk alone reduced the number of offspring produced per year by 40%. Our results suggest that the perception of predation risk is itself powerful enough to affect wildlife population dynamics, and should thus be given greater consideration in vertebrate conservation and management.

BIRDSONG AND HUMAN SPEECH: Common Themes and Mechanisms

1999-03-01

Allison J. Doupe , Patricia K. Kuhl

▪ Abstract Human speech and birdsong have numerous parallels. Both humans and songbirds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will … ▪ Abstract Human speech and birdsong have numerous parallels. Both humans and songbirds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will imitate, as well as themselves as they practice, and a waning of this dependence as they mature. Innate predispositions for perceiving and learning the correct sounds exist in both groups, although more evidence of innate descriptions of species-specific signals exists in songbirds, where numerous species of vocal learners have been compared. Humans also share with songbirds an early phase of learning that is primarily perceptual, which then serves to guide later vocal production. Both humans and songbirds have evolved a complex hierarchy of specialized forebrain areas in which motor and auditory centers interact closely, and which control the lower vocal motor areas also found in nonlearners. In both these vocal learners, however, how auditory feedback of self is processed in these brain areas is surprisingly unclear. Finally, humans and songbirds have similar critical periods for vocal learning, with a much greater ability to learn early in life. In both groups, the capacity for late vocal learning may be decreased by the act of learning itself, as well as by biological factors such as the hormones of puberty. Although some features of birdsong and speech are clearly not analogous, such as the capacity of language for meaning, abstraction, and flexible associations, there are striking similarities in how sensory experience is internalized and used to shape vocal outputs, and how learning is enhanced during a critical period of development. Similar neural mechanisms may therefore be involved.

An Ethological Perspective on Common Cross-Language Utilization of F₀ of Voice

1984-01-01

John J. Ohala

Abstract The author suggests that the following seemingly disparate phenomena have an underlying relationship: (a) cross-language similarities in the intonation contours for statements versus questions, (b) cross-cultural similarities in the … Abstract The author suggests that the following seemingly disparate phenomena have an underlying relationship: (a) cross-language similarities in the intonation contours for statements versus questions, (b) cross-cultural similarities in the vocal expression via intonation of attitude and affect, (c) cross-language patterns in the use of tone, vowels, and consonants in ‘sound symbolic’ vocabulary, (d) cross-species use of F₀ in threatening or non threatening vocalizations, (e) cross-cultural and cross-species use of certain facial expressions (involving distinct mouth shape), and (f) the existence of sexual dimorphism in the vocal anatomy of humans (and certain non humans). He argues that all arise due to an innately specified ‘frequency code’, which associates high acoustic frequency with the primary meaning of ‘small vocalizer’ and thus such secondary meanings as ‘subordinate, submissive, non threatening, desirous of the receiver’s goodwill, etc’ and associates with low acoustic frequency the primary meaning of ‘large vocalizer’ and such secondary meanings as ‘dominant, aggressive, threatening, etc’

The evolution of speech: a comparative review

2000-07-01

W. Tecumseh Fitch

A comparative study of the behavioral deficits following lesions of various parts of the zebra finch song system: implications for vocal learning

1991-09-01

Constance Scharff , Fernando Nottebohm

Song production in song birds is controlled by an efferent pathway. Appended to this pathway is a "recursive loop" that is necessary for song acquisition but not for the production … Song production in song birds is controlled by an efferent pathway. Appended to this pathway is a "recursive loop" that is necessary for song acquisition but not for the production of learned song. Since zebra finches learn their song by imitating external models, we speculated that the importance of the recursive loop for learning might derive from its processing of auditory feedback during song acquisition. This hypothesis was tested by comparing the effects on song in birds deafened early in life and birds with early lesions in either of two nuclei--Area X and the lateral magnocellular nucleus of the anterior neostriatum (LMAN). These nuclei are part of the recursive loop. The three treatments affected song development differently, as reflected by various parameters of the adult song of these birds. Whereas LMAN lesions resulted in songs with monotonous repetitions of a single note complex, songs of Area X-lesioned birds consisted of rambling series of unusually long and variable notes. Furthermore, whereas song of LMAN lesioned birds stabilized early, song stability as seen in intact birds was never achieved in Area X-lesioned birds. Early deafness also resulted in poorly structured and unstable song. We conclude that Area X and LMAN contribute differently to song acquisition: the song variability that is typical of vocal development persists following early deafness or lesions of Area X but ends abruptly following removal of LMAN. Apparently, LMAN plays a crucial role in fostering the kinds of circuit plasticity necessary for learning.

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Soundscape Ecology: The Science of Sound in the Landscape

2011-03-01

Bryan C. Pijanowski , Luis J. Villanueva-Rivera , Sarah L. Dumyahn +5 more

This article presents a unifying theory of soundscape ecology, which brings the idea of the soundscape—the collection of sounds that emanate from landscapes—into a research and application focus. Our conceptual … This article presents a unifying theory of soundscape ecology, which brings the idea of the soundscape—the collection of sounds that emanate from landscapes—into a research and application focus. Our conceptual framework of soundscape ecology is based on the causes and consequences of biological (biophony), geophysical (geophony), and human-produced (anthrophony) sounds. We argue that soundscape ecology shares many parallels with landscape ecology, and it should therefore be considered a branch of this maturing field. We propose a research agenda for soundscape ecology that includes six areas: (1) measurement and analytical challenges, (2) spatial-temporal dynamics, (3) soundscape linkage to environmental covariates, (4) human impacts on the soundscape, (5) soundscape impacts on humans, and (6) soundscape impacts on ecosystems. We present case studies that illustrate different approaches to understanding soundscape dynamics. Because soundscapes are our auditory link to nature, we also argue for their protection, using the knowledge of how sounds are produced by the environment and humans.

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Central control of song in the canary, Serinus canarius

1976-02-15

Fernando Nottebohm , Tegner M. Stokes , Christiana M. Leonard

We have traced central nervous pathways controlling bird song in the canary using a combination of behavioral and anatomical techniques. Unilateral electrolytic brain lesions were made in adult male canaries … We have traced central nervous pathways controlling bird song in the canary using a combination of behavioral and anatomical techniques. Unilateral electrolytic brain lesions were made in adult male canaries whose song had been previously recorded and analysed on a sound spectrograph. After several days of postoperative recording, the birds were sacrificed and their brains processed histologically for degeneration staining with the Fink-Heimer technique. Although large lesions in the neostriatum and rostral hyperstriatum had no effect on song, severe song deficits followed damage to a discrete large-celled area in the caudal hyperstriatum ventrale (HVc). Degenerating fibers were traced from this region to two other discrete nuclei in the forebrain: one in the parolfactory lobe (area X, a teardrop-shaped small-celled nucleus); and a round large-celled nucleus in the archistriatum (RA). Unilateral lesion of X had no effect on song; lesions of RA, however, caused severe song deficits. Degenerating fibers from RA joined the occipitomesencephalic tract and had widespread ipsilateral projections to the thalamus, nucleus intercollicularis of the midbrain, reticular formation, and medulla. It is of particular interest that direct connections were found onto the cells of the motor nucleus innervating the syrinx, the organ of song production. Unilateral lesions of n. intercollicularis (previously implicated in the control of vocal behavior) had little effect on song. One bilateral lesion of HVc resulted in permanent (9 months) and complete elimination of the audible components of song, although the bird assumed the posture and movements typical of song. Preliminary data suggest that lesions of the left hemisphere result in greater deficits than lesions of the right one. This finding is consistent with earlier reports that the left syrinx controls the majority of song components. Results reported here suggest a localization of vocal control in the canary brain with an overlying left hemispheric dominance.

Principles of animal communication

2012-05-01

Part 1 Production, transmission, and reception of signals: the properties of sound fourier analysis sound production sound propogation sound reception properties of light production and transmission of light signals light … Part 1 Production, transmission, and reception of signals: the properties of sound fourier analysis sound production sound propogation sound reception properties of light production and transmission of light signals light signal reception chemical signals electroreception. Part 2 Optimizing information transfer: optimizing communication the amount of information the value of information coding signal evolution costs and constraints on signal evolution signal design rules. Part 3 Game theory and signalling strategies: evolutionary game theory signal honesty conflict resolution territorial signalling games mating games and signalling social integration environmental signals autocommunication.

Structural Changes Accompanying Memory Storage

1993-10-01

Craig H. Bailey , Eric R. Kandel

Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, … Macrophage polarization refers to how macrophages have been activated at a given point in space and time. Polarization is not fixed, as macrophages are sufficiently plastic to integrate multiple signals, such as those from microbes, damaged tissues, and ...Read More

How animals communicate

1978-11-01

Charles T. Snowdon

<scp>BORIS</scp>: a free, versatile open‐source event‐logging software for video/audio coding and live observations

2016-05-04

Olivier Friard , Marco Gamba

Summary Quantitative aspects of the study of animal and human behaviour are increasingly relevant to test hypotheses and find empirical support for them. At the same time, photo and video … Summary Quantitative aspects of the study of animal and human behaviour are increasingly relevant to test hypotheses and find empirical support for them. At the same time, photo and video cameras can store a large number of video recordings and are often used to monitor the subjects remotely. Researchers frequently face the need to code considerable quantities of video recordings with relatively flexible software, often constrained by species‐specific options or exact settings. BORIS is a free, open‐source and multiplatform standalone program that allows a user‐specific coding environment to be set for a computer‐based review of previously recorded videos or live observations. Being open to user‐specific settings, the program allows a project‐based ethogram to be defined that can then be shared with collaborators, or can be imported or modified. Projects created in BORIS can include a list of observations, and each observation may include one or two videos (e.g. simultaneous screening of visual stimuli and the subject being tested; recordings from different sides of an aquarium). Once the user has set an ethogram, including state or point events or both, coding can be performed using previously assigned keys on the computer keyboard. BORIS allows definition of an unlimited number of events (states/point events) and subjects. Once the coding process is completed, the program can extract a time‐budget or single or grouped observations automatically and present an at‐a‐glance summary of the main behavioural features. The observation data and time‐budget analysis can be exported in many common formats ( TSV , CSV , ODF , XLS , SQL and JSON ). The observed events can be plotted and exported in various graphic formats ( SVG , PNG , JPG , TIFF , EPS and PDF ).

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Adaptations for Acoustic Communication in Birds: Sound Transmission and Signal Detection

1982-01-01

R. Haven Wiley , Douglas G. Richards

Acoustic Communication in Birds

1982-01-01

Ecology and evolution of acoustic communication in birds

1997-01-01

Animal Signals

2003-11-06

John Maynard Smith , D. Harper

Abstract Why are animal signals reliable? This is the central problem for evolutionary biologists interested in signals. Of course, not all signals are reliable; but most are, otherwise receivers of … Abstract Why are animal signals reliable? This is the central problem for evolutionary biologists interested in signals. Of course, not all signals are reliable; but most are, otherwise receivers of signals would ignore them. A number of theoretical answers have been proposed and empirical studies made, but there still remains a considerable amount of confusion. The authors, one a theoretician the other a fieldworker, introduce a sense of order to this chaos. A significant cause of confusion has been the tendency for different researchers to use either the same term with different meanings, or different terms with the same meaning. The authors attempt to clarify these differences. A second cause of confusion has arisen because many biologists continue to assume that there is only one correct explanation for signal reliability. The authors argue that the reliability of signals is maintained in several ways, relevant in different circumstances, and that biologists must learn to distinguish between them. In this book they explain the different theories, give examples of signalling systems to which one or another theory applies, and point to the many areas where further work, both theoretical and empirical, is required. John Maynard Smith is one of the most influential scientists of his generation and his theories have transformed our understanding of animal behaviour, whilst David Harper is a reknowned field ecologist. Animal signals are one of the hottest and most controversial subjects in animal behaviour, and are also of major importance to an understanding of human behaviour and the evolution of language.

Nature's music: the science of birdsong

2005-05-01

Peter Marler , Hans Slabbekoorn

Science and birdsong: the good old days Vocal fighting and flirting: the functions of birdsong Learning to sing The diversity and plasticity of birdsong Bird calls: a cornucopia for communication … Science and birdsong: the good old days Vocal fighting and flirting: the functions of birdsong Learning to sing The diversity and plasticity of birdsong Bird calls: a cornucopia for communication Singing in the wild: the ecology of birdsong Audition: can birds hear everything they sing? Brains and birdsong How birds sing and why it matters Birdsong and evolution Performance limits on birdsong Birdsong and conservation Grey parrots: learning and using speech Singing, socializing, and the music effect

Geographical variation in the songs of two closely related song-learning species, Anna's and Costa's hummingbird

2025-06-24

A Berger , Wenliang Ye , Tadashi KONDO +3 more | Animal Behaviour

Synaptic connectivity of sensorimotor circuits for vocal imitation in the songbird

2025-06-23

Massimo Trusel , Ziran Zhao , Danyal H Alam +3 more | eLife

Sensorimotor computations for learning and behavior rely on precise patterns of synaptic connectivity. Yet, we typically lack the synaptic wiring diagrams for long-range connections between sensory and motor circuits in … Sensorimotor computations for learning and behavior rely on precise patterns of synaptic connectivity. Yet, we typically lack the synaptic wiring diagrams for long-range connections between sensory and motor circuits in the brain. Here, we provide the synaptic wiring diagram for sensorimotor circuits involved in learning and production of male zebra finch song, a natural and ethologically relevant behavior. We examined the functional synaptic connectivity from the 4 main sensory afferent pathways onto the three known classes of projection neurons of the song premotor cortical region HVC. Recordings from hundreds of identified projection neurons reveal rules for monosynaptic connectivity and the existence of polysynaptic ensembles of excitatory and inhibitory neuronal populations in HVC. Circuit tracing further identifies novel connections between HVC’s presynaptic partners. Our results indicate a modular organization of ensemble-like networks for integrating long-range input with local circuits, providing important context for information flow and computations for learned vocal behavior.

Implementation of a Wildlife Intrusion Detection Framework Using Raspberry Pi

2025-06-22

Mahesh Mudavath | International Scientific Journal of Engineering and Management

Abstract - Wildlife intrusion into human habitats, agricultural fields, or railway tracks can result in serious consequences including crop damage, human-wildlife conflict, and even accidents. To mitigate these challenges, an … Abstract - Wildlife intrusion into human habitats, agricultural fields, or railway tracks can result in serious consequences including crop damage, human-wildlife conflict, and even accidents. To mitigate these challenges, an intelligent and cost-effective surveillance system is essential. This paper proposes a real-time wildlife intrusion detection system built using a Raspberry Pi microcontroller integrated with sensors and camera modules. The system utilizes motion detection and image processing techniques to detect the presence of animals and sends instant alerts via wireless communication. Experimental results demonstrate the effectiveness of the proposed setup in real-time intrusion scenarios with minimal power consumption and high accuracy. Key Words: Wildlife intrusion, Raspberry Pi, motion detection, IoT, surveillance, image processing.

Consistent and scalable monitoring of birds and habitats along a coffee production intensity gradient

2025-06-21

Marius Somveille , Joe Grainger‐Hull , Nicole Ferguson +7 more | Remote Sensing in Ecology and Conservation

Abstract Land use change associated with agricultural intensification is a leading driver of biodiversity loss in the tropics. To evaluate the habitat–biodiversity relationship in production systems of tropical agricultural commodities, … Abstract Land use change associated with agricultural intensification is a leading driver of biodiversity loss in the tropics. To evaluate the habitat–biodiversity relationship in production systems of tropical agricultural commodities, birds are commonly used as indicators. However, a consistent and reliable methodological approach for monitoring tropical avian communities and habitat quality in a way that is scalable is largely lacking. In this study, we examined whether the automated analysis of audio data collected by passive acoustic monitoring, together with the analysis of remote sensing data, can be used to efficiently monitor avian biodiversity along the gradient of habitat degradation associated with the intensification of coffee production. Coffee is an important crop produced in tropical forested regions, whose production is expanding and intensifying, and coffee production systems form a gradient of ecological complexity ranging from forest‐like shaded polyculture to dense sun‐exposed monoculture. We used LiDAR technology to survey the habitat, together with autonomous recording units and a vocalization classifier to assess bird community composition in a coffee landscape comprising a shade‐grown coffee farm, a sun coffee farm and a forest remnant, located in southern Mexico. We found that LiDAR can capture relevant variation in vegetation across the habitat gradient in coffee systems, specifically matching the generally observed pattern that the intensification of coffee production is associated with a decrease in vegetation density and complexity. We also found that bioacoustics can capture known functional signatures of avian communities across this habitat degradation gradient. Thus, we show that these technologies can be used in a robust way to monitor how biodiversity responds to land use intensification in the tropics. A major advantage of this approach is that it has the potential to be deployed cost‐effectively at large scales to help design and certify biodiversity‐friendly productive landscapes.

Eco-Friendly Crop Protection Using Solar Powered Sound Sensors

2025-06-21

Shivanand , A. M. Patil , Syed F. Ali +1 more | International Journal of Latest Technology in Engineering Management & Applied Science

Abstract: Crop loss due to wild animals and birds remains a persistent challenge for farmers, especially in rural and semi-rural areas. Traditional methods such as scarecrows, fencing, and chemical deterrents … Abstract: Crop loss due to wild animals and birds remains a persistent challenge for farmers, especially in rural and semi-rural areas. Traditional methods such as scarecrows, fencing, and chemical deterrents often prove either ineffective in the long term or environmentally harmful. This research presents an eco-friendly and sustainable approach to crop protection using solar-powered sound sensors. The proposed system utilizes non-conventional solar energy to power sound-emitting devices triggered by motion or sound detection. When an intruder—such as a bird or animal—is detected in the field, the device emits high-frequency or predator-like sounds that naturally repel them without causing harm. This technology reduces dependence on electricity and chemical repellents, offering a cost-effective solution for farmers. Field tests showed a notable reduction in crop damage while maintaining ecological balance. The design is simple, requires minimal maintenance, and can be adapted to different crop environments. This study illustrates that integrating solar energy with sound-based deterrence is a viable strategy for modern, sustainable agriculture.

Do as I do imitation in a steller sea lion Eumetopias jubatus

2025-06-20

Masahiro Sasaki , Hirotaka Kinoshita , Akitsugu Konno | Animal Cognition

Abstract The present study explored whether a well-socialized Steller sea lion named Hama could reproduce similar actions with human demonstrations using the “Do as I do” (DAID) paradigm. Hama had … Abstract The present study explored whether a well-socialized Steller sea lion named Hama could reproduce similar actions with human demonstrations using the “Do as I do” (DAID) paradigm. Hama had learned 50 types of behaviors, but her social learning ability was unknown. In Study 1, we trained Hama to produce simultaneous DAID responses. After introducing the DAID training, we conducted four tests to confirm Hama’s acquisition of demonstrator-matching behavior. We found that Hama successfully acquired the action-matching ability for human actions, not only with three trained actions but also with six out of seven untrained actions (see Test 1 and Test 2). Moreover, Hama’s DAID performance was stable regardless of the familiarity of human demonstrators (see Test 1 and Test 2). Hama successfully performed two completely novel body actions that were not included in her prior learning repertoire, but failed to replicate actions involving object manipulation (see Test 3). She showed no response in control trials without demonstrations, providing partial evidence for negative control (see Test 4). In Study 2, we introduced Hama to performing non-simultaneous DAID responses, which involved suppressing immediate simultaneous actions following the demonstrator and then reproducing the actions upon the verbal cue “Go.” She accurately performed the DAID response even when she delayed her response until the demonstrator’s demonstration was completed (Test 5). Importantly, she reproduced the action accurately when visual contact between the demonstrator and herself was blocked after the demonstration, eliminating the Clever Hans effect as a potential influence on her simultaneous DAID response (Test 6). However, she could not reproduce small or untrained actions (Test 7). These results suggest that Hama may be able to accurately map human action sequences in body-oriented actions to some extent. This study provides the first evidence of motor imitation ability in captive pinnipeds.

Detection of Bird Species Found in Bhutan Using Vision Transformer-based Transfer Learning

2025-06-19

Karma Wangchuk , Tandin Wangchuk , Tsheten Dorji | Zorig Melong.

Birdwatching is an emerging recreational activity in Bhutan, attracting both local enthusiasts and international tourists due to the country's rich avian biodiversity. This growing interest contributes to local tourism and … Birdwatching is an emerging recreational activity in Bhutan, attracting both local enthusiasts and international tourists due to the country's rich avian biodiversity. This growing interest contributes to local tourism and economic development. However, accurate bird identification remains a challenge due to variations in size, shape, and coloration, compounded by inconsistencies in English and Dzongkha nomenclature. Traditional identification methods, which rely on field guides and expert observations, are often prone to errors and disagreements. To address this limitation, we developed a bird detection and recognition system utilizing image processing and machine learning techniques. Bird images were collected from birdwatchers in Paro, Thimphu, and Trongsa, as well as from the Kaggle dataset. These images underwent preprocessing and augmentation to construct a comprehensive dataset. The study considered 23 bird species, and the model was fine-tuned using Google’s pre-trained transformer encoder for image recognition, operating at a resolution of 244×244 with 16×16 patches. The model was trained on a dataset of 3,595 images, leading to a significant reduction in training and validation losses, from 2.8491 and 1.2231 to 0.0030 and 0.0529, respectively. The results indicate the effectiveness of the proposed approach in enhancing bird species identification, offering a valuable tool for birdwatchers and conservation efforts in Bhutan.

Beyond mating calls: unveiling the acoustic complexity in an endangered foam-nesting frog of north-eastern Brazil

2025-06-18

Emerson Gonçalves Dias , Ednilza Maranhão dos Santos , Pedro Ivo Simões | Bioacoustics

Cultural and morphological divergence of Darwin's cactus finches (Geospiza scandens) across the Galapagos Islands

2025-06-18

Melanie Kaluppa , Jefferson García-Loor , Alper Yelimlieş +2 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Understanding the divergence of cultural traits, such as bird song, provides critical insights into evolutionary processes. In geographically isolated populations, the divergence of traits associated with mate choice can … Abstract Understanding the divergence of cultural traits, such as bird song, provides critical insights into evolutionary processes. In geographically isolated populations, the divergence of traits associated with mate choice can lead to further genetic separation. This study investigates divergence in song syllable types, acoustic characteristics, singing behavior, and morphology in two allopatric populations of Darwin’s cactus finch ( Geospiza scandens ) on Floreana and Santa Cruz Islands in the Galápagos Archipelago. Using song recordings of 50 males, we identified 25 syllable types with no overlap between islands, indicating a complete divergence in syllable repertoires. Syllables of Floreana and Santa Cruz males diverged in the acoustic space largely due to broader frequency bandwidths on Floreana. Moreover, Floreana males had smaller beaks than Santa Cruz males. Despite acoustic and morphological divergence, singing behaviors - like syllable repetition rate and number of syllables per song - did not differ significantly. Both cultural processes, including drift and transmission biases, as well as selection on morphology could have contributed to the observed acoustic divergence. This study adds to a growing literature on the role of geographic separation in the accumulation of both cultural and morphological divergence between populations. Future research could interrogate speciation scenarios in cactus finches if populations cease to interbreed after secondary contact.

Yellowhammer (Emberiza citrinella) males sing using individual isochronous rhythms and maximise rhythmic dissimilarity with neighbours

2025-06-17

Anna N. Osiecka , Marcos Quiroz‐Oliva , J. Kouřil +2 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract The temporal structure of an animal’s vocal output can be cognitively controlled, presenting an interesting aspect for vocal learning species that benefit from diversification. Although birdsong is the most … Abstract The temporal structure of an animal’s vocal output can be cognitively controlled, presenting an interesting aspect for vocal learning species that benefit from diversification. Although birdsong is the most thoroughly studied aspect of animal communication, its rhythms remain largely unknown. Here, we revisit the question of vocal individuality in the songs of male yellowhammers ( Emberiza citrinella ) purely from a rhythmic perspective. Yellowhammers use simple songs composed of two phrases: the initial phrase , with one individual usually having a repertoire of on average two such phrase types, and the dialect phrase containing the dialect that is the same for all males at a given locality. Some of the initial phrases are commonly shared between various males, but their combinations and frequency contours are individually unique and temporally stable. Using focal recordings of 38 known individuals, collected over three years in the same geographic location, we calculated a set of nine temporal indices to describe each song and compared individuals in a permuted discriminant function analysis. Subsequently, we calculated the potential for individual coding for each of these parameters. To assess whether rhythmic similarity may depend on the singers’ proximity, we calculated vocal dissimilarity as the Euclidean distances between each two males, and used Kendall’s correlation. We show that yellowhammer males use individual rhythms, maintained over different phrase types and carried mostly in the inter-onset-interval variability and syllable rate, as in syllables per second, within the song. There were particularly strong rhythmic differences between singers among the closest neighbours, which decreased over the first 600 m. There was no pattern for neighbours beyond this distance. This study is the first to demonstrate the existence of strong individuality based purely on rhythm, as well as rhythmic differentiation from neighbours, in a songbird. Abstract Figure

The role of learned song in the evolution and speciation of Eastern and Spotted towhees

2025-06-17

Ximena León Du’Mottuchi , Nicole Creanza | PLoS Computational Biology

Oscine songbirds learn vocalizations that function in mate attraction and territory defense; sexual selection pressures on these learned songs could thus accelerate speciation. The Eastern and Spotted towhees are recently … Oscine songbirds learn vocalizations that function in mate attraction and territory defense; sexual selection pressures on these learned songs could thus accelerate speciation. The Eastern and Spotted towhees are recently diverged sister species that now have partially overlapping ranges with evidence of some hybridization. Widespread community-science recordings of these species, including songs within their zone of overlap and from potential hybrids, enable us to investigate whether song differentiation might facilitate their reproductive isolation. Here, we quantify 16 song features to analyze geographic variation in Spotted and Eastern towhee songs and assess species-level differences. We then use several machine learning models to measure how accurately their songs can be classified by species. While no single song feature reliably distinguishes the two species, machine learning models classified songs with relatively high accuracy (random forest: 89.5%, deep learning: 90%, gradient boosting machine: 88%, convolutional neural network: 88%); interestingly, species classification was less accurate in their zone of overlap. Finally, our analysis of the limited publicly available genetic data from each species supports the hypothesis that the species are reproductively isolated. Together, our results suggest that small variations in multiple features may contribute to these sister species’ ability to recognize their species-specific songs.

The influences of urbanization on breeding behavior of American bullfrog (Aquarana catesbeiana) in South Korea

2025-06-17

Jia Lee , Md Mizanur Rahman , Seung‐Ju Cheon +2 more | PLoS ONE

Urbanized areas often exhibit high levels of anthropogenic noise, which can mask or interfere with animal communication signals, especially those that use sound to communicate, making it challenging for individuals … Urbanized areas often exhibit high levels of anthropogenic noise, which can mask or interfere with animal communication signals, especially those that use sound to communicate, making it challenging for individuals to detect and interpret acoustic cues. While calling is crucial for anuran breeding and communication, the coping mechanisms of city dwelling and cosmopolitan species in urbanized environments remain understudied. Given that invasive species have higher environmental adaptability than native species (because of habitat specificity and environmental sensitivity), we studied the calling patterns of the invasive American bullfrog ( Aquarana catesbeiana ) in different levels of urbanized areas in South Korea. In our study, we found an early onset of calling activities in urbanized A. catesbeiana populations, which suggests a change induced by factors related to urbanization on breeding phenology. Additionally, urban populations show more intense diurnal calling activities but shorter breeding periods than non-urban populations. The results indicate water temperature and urban noise as the leading factors influencing calling activities in A. catesbeiana . Urbanization induced changes in breeding and calling activities might have facilitated A. catesbeiana to invade and establish populations outside their natural ecological niches. Thus, this study sheds light on the effect of urbanization on frog breeding activities and how an invasive species copes with modified environments in new areas.

Lack of sex-specific syllables and high female song variability support relaxed selection on female song in Orchard Orioles ( Icterus spurius )

2025-06-16

D’Juan A. Moreland , Aiman Raza , Olivia L. Brooks +2 more | The Wilson Journal of Ornithology

Typological, Phylogenetic, and Areal Properties of Conative Animal Calls in Ewe

2025-06-16

Alexander Andrason , Gabriel Kwasi Gafatsi | Rocznik Orientalistyczny/Yearbook of Oriental Studies

This article is dedicated to conative animal calls (CACs) in Ghanaian Ewe (Kwa). The study is couched within a ‘radial-network-with-prototype-effects’ approach to linguistic categorisation and examines the typological features of … This article is dedicated to conative animal calls (CACs) in Ghanaian Ewe (Kwa). The study is couched within a ‘radial-network-with-prototype-effects’ approach to linguistic categorisation and examines the typological features of CACs (phonetics and morphology) as well as their phylogenetic (cognate) and areal (contact-induced) properties. Drawing on previous works on CACs, fieldwork activities involving seven speakers of Ewe, and the native-speaker competence of one of the authors, a set of 17 primary CACs is identified and complemented with an open class of (poorly lexicalised) secondary CACs. The analysis of the material collected demonstrates that Ewe CACs comply with the formal features associated with the prototype of a CAC and, when treated holistically, the CAC category fulfils its typological profile. The canonicity degree exhibited by Ewe CACs closely matches that reported for another Kwa language, Akan, with some CACs being (nearly) identical in both languages. The authors argue that this lexemic similarity most likely stems from crosslinguistic tendencies and thus instantiates the phenomenon of parallel development instead of having an areal or phylogenetic motivation.

Always together: an extremely long pair bond in rufous horneros

2025-06-16

Pedro Diniz | Ornithology Research

Long-term variability in the song of the thrush nightingale (Luscinia luscinia) and its relations to the territorial behavior of males

2025-06-14

В. В. Иваницкий , Julia Bezrukova , Anastasia Grebenkova +4 more | Behavioural Processes

Bird Sound Prediction

2025-06-14

Rajlaxmi Kasture | International Scientific Journal of Engineering and Management

ABSTRACT - This paper presents a machine learning-based system designed for recognizing bird species from their vocalizations. Leveraging Artificial Neural Networks (ANNs), specifically a Multilayer Perceptron (MLP), the system processes … ABSTRACT - This paper presents a machine learning-based system designed for recognizing bird species from their vocalizations. Leveraging Artificial Neural Networks (ANNs), specifically a Multilayer Perceptron (MLP), the system processes pre-recorded bird calls, extracts Mel Frequency Cepstral Coefficients (MFCCs), and classifies the sound using a trained ANN model. The proposed system is computationally efficient and accurate, making it a valuable tool for ecological research and conservation. The system is deployed via a user-friendly Flask web interface for real-time usage. Keywords: Bird Sound Recognition, Deep Learning, MFCC, Librosa , TensorFlow, Flask KeyWords: optics, photonics, light, lasers, stencils, journals

Context-dependent frequency alteration in a treefrog

2025-06-13

Ke Deng , Qiao-Ling He , Tongliang Wang +2 more | Animal Cognition

Accelerando and crescendo in African penguin ecstatic display songs

2025-06-13

Taylor A. Hersh , Yannick Jadoul , Marco Gamba +2 more | Annals of the New York Academy of Sciences

Abstract Many species produce rhythmic sound sequences. Some purportedly speed up their vocalizations throughout a display, reminiscent of—but not necessarily equivalent to— accelerando in human music. This phenomenon has been … Abstract Many species produce rhythmic sound sequences. Some purportedly speed up their vocalizations throughout a display, reminiscent of—but not necessarily equivalent to— accelerando in human music. This phenomenon has been frequently reported but rarely quantified, which limits our ability to understand its mechanism, function, and evolution. Here, we use a suite of rhythm analyses to quantify temporal and acoustic features in the ecstatic display songs of male African penguins ( Spheniscus demersus ). We show that songs get faster (i.e., accelerando) and louder (i.e., crescendo) as they progress. The accelerando occurs because the intersyllable silences, not the syllables themselves, predictably shorten over time. This rhythmicity is maintained even when individuals take audible breaths. Individuals also show plasticity: when they start with a slow tempo, they speed up more strongly than when they start with a fast tempo. We hypothesize that this well‐timed accelerando may stem from arousal‐based mechanisms, biomechanical constraints, or more complex rhythmic control. Future work should test the mechanisms behind this intra‐individual rhythmic variation since nonpasserine birds are thought to have limited vocal plasticity. By integrating a rich empirical dataset with cutting‐edge rhythm analyses, we establish the necessary foundation to determine how such features evolved and their role(s) across communication systems.

Evaluating the influencers of acoustic indices in a zoo soundscape

2025-06-13

Oliver Jepson , R. Tucker Gilman , Leah J. Williams +1 more | Bioacoustics

Shouldering the challenge of deciphering avian palate evolution

2025-06-13

Juan Benito , Pei‐Chen Kuo , Christopher R. Torres +5 more | bioRxiv (Cold Spring Harbor Laboratory)

Wilken et al. (1) investigate the evolution of avian palatal kinesis using comparative morphology and biomechanical modelling. While the topic of the study and its approach are timely, its conclusions … Wilken et al. (1) investigate the evolution of avian palatal kinesis using comparative morphology and biomechanical modelling. While the topic of the study and its approach are timely, its conclusions are marred by inadequate taxon sampling and morphological misinterpretations.

Captive Male and Female West Indian Manatees Display Variable Vocal and Behavioral Responses to Playbacks of Conspecifics

2025-06-13

Beth Brady , Eric Angel Ramos , Jake A. Lasala +5 more | Marine Mammal Science

ABSTRACT Manatees exhibit diverse vocalizations in various behavioral contexts, but the exact role of these sounds, particularly in terms of sex‐based distinctions, remains elusive. This study sought to discern the … ABSTRACT Manatees exhibit diverse vocalizations in various behavioral contexts, but the exact role of these sounds, particularly in terms of sex‐based distinctions, remains elusive. This study sought to discern the behavioral and vocal responses of two subspecies of captive West Indian manatees ( Trichechus manatus ) to different call types (squeaks and squeals) to determine whether differences are related to the sex of the signaler. In Mexico, four female Antillean manatees ( Trichechus manatus manatus ) were subjected to playbacks, while in Florida, two male Florida manatees ( Trichechus manatus latirostris ) were used for a parallel experiment. Vocal responses were captured using two hydrophones, with an underwater speaker system facilitating the playback. Video footage was collected to observe behavioral changes in response to playback. Results indicated that neither male nor female manatees increased the number of calls, changed call type, or altered acoustic parameters regardless of call type or whether the sound played was male or female. Likewise, neither males nor females significantly altered their behavior or movement towards the speaker in response to male or female calls, or call type. However, individual Antillean manatees exhibited variation in their behavioral responses to playback of conspecific vocalizations. The results suggest that manatees may not distinguish between the sex of callers.

Change of spiny neuron structure in the basal ganglia song circuit and its regulation by miR-9 during song development

2025-06-13

Hannah Jarrell , Ansab Akhtar , Max Horowitz +4 more | Journal of Neuroscience

Juvenile zebra finches learn to sing by imitating conspecific songs of adults during a sensitive period early in life. Area X is a basal ganglia nucleus of the song control … Juvenile zebra finches learn to sing by imitating conspecific songs of adults during a sensitive period early in life. Area X is a basal ganglia nucleus of the song control circuit specialized for song-related sensory-motor learning during song development. The structural plasticity and the molecular mechanisms regulating neuronal structure in Area X during song development and maturation are unclear. In this study, we examined the structure of spiny neurons, the main neuron type in Area X, at key stages of song development in male zebra finches. We report that dendritic arbor of spiny neurons expands during the sensitive period for song learning, and this initial growth is followed by pruning of dendrites and spines accompanied by changes in spine morphology as the song circuit matures. Previously, we showed that overexpression of miR-9 in Area X impairs song learning and performance and alters the expression of many genes that have important roles in neuronal structure and function (Shi et al., 2018). As an extension of that study, we report here that overexpression of miR-9 in spiny neurons in juvenile zebra finches reduces dendritic arbor complexity and spine density in a developmental stage-specific manner. We also show that miR-9 regulates structural maintenance of spiny neurons in adulthood. Together, these findings reveal dynamic microstructural changes in the song circuit during the sensitive period of song development and provide evidence that miR-9 regulates neuronal structure during song development and maintenance. Significance Statement Song development in juvenile zebra finches provides a model to study sensitive period plasticity for language development and related neural developmental disorders in humans. Area X is a basal ganglia nucleus essential for song-related sensory-motor learning in the zebra finch. We show that dendritic arbor of spiny neurons in Area X undergoes an initial growth and expansion followed by pruning of dendrites and spines during song development, and that this process is regulated by miR-9 in a developmental stage specific manner. These findings reveal the temporal profiles of structural development of key neurons in the basal ganglia song circuit and reveal a possible molecular mechanism for restricting sensitive period plasticity during vocal development.

ArcticSoundsNET: BirdNET embeddings facilitate improved bioacoustic classification of Arctic species

2025-06-13

Morgan A. Ziegenhorn , Richard B. Lanctot , Stephen C. Brown +6 more | Ecological Informatics

Using tropical reef, bird and unrelated sounds for superior transfer learning in marine bioacoustics

2025-06-12

Ben Williams , Bart van Merriënboer , Vincent Dumoulin +7 more | Philosophical Transactions of the Royal Society B Biological Sciences

Machine learning has the potential to revolutionize passive acoustic monitoring (PAM) for ecological assessments. However, high annotation and computing costs limit the field’s adoption. Generalizable pretrained networks can overcome these … Machine learning has the potential to revolutionize passive acoustic monitoring (PAM) for ecological assessments. However, high annotation and computing costs limit the field’s adoption. Generalizable pretrained networks can overcome these costs, but high-quality pretraining requires vast annotated libraries, limiting their current development to data-rich bird taxa. Here, we identify the optimum pretraining strategy for data-deficient domains, using tropical reefs as a representative case study. We assembled ReefSet, an annotated library of 57 000 reef sounds taken across 16 datasets, though still modest in scale compared to annotated bird libraries. We performed multiple pretraining experiments and found that pretraining on a library of bird audio 50 times the size of ReefSet provides notably superior generalizability on held-out reef datasets, with a mean area under the receiver operating characteristic curve (AUC-ROC) of 0.881 (±0.11), compared to pretraining on ReefSet itself or unrelated audio, with a mean AUC-ROC of 0.724 (±0.05) and 0.834 (±0.05), respectively. However, our key findings show that cross-domain mixing, where bird, reef and unrelated audio are combined during pretraining, provides superior transfer learning performance, with an AUC-ROC of 0.933 (±0.02). SurfPerch, our optimum pretrained network, provides a strong foundation for automated analysis of tropical reef and related PAM data with minimal annotation and computing costs. This article is part of the theme issue ‘Acoustic monitoring for tropical ecology and conservation’.

Forest elephants modulate their behaviour to adapt to sounds of danger

2025-06-12

Anahita K. Verahrami , Colin R. Swider , Frelcia Bien-Dorvillion Bambi +4 more | Philosophical Transactions of the Royal Society B Biological Sciences

The African forest elephant ( Loxodonta cyclotis ) plays a critical role in upholding the Congo Basin’s structure and function, a vital area that supports global carbon sequestration. However, between … The African forest elephant ( Loxodonta cyclotis ) plays a critical role in upholding the Congo Basin’s structure and function, a vital area that supports global carbon sequestration. However, between 1990 and 2021, the species’ numbers declined by 86%, mainly because of ivory hunting. Owing to their elusive nature in the region’s dense rainforests, their responses to human disturbances, such as gun hunting, are not well understood, though the limited studies that have been completed suggest that forest elephants may respond by altering their abundance, distribution and nocturnal activity. Using passive acoustic monitoring (PAM) in and around Nouabalé-Ndoki National Park, Republic of Congo, we assess how gun hunting impacts forest elephant occupancy and night-time vocal activity. Findings reveal that elephant occupancy drops from 0.54 to 0.52 following a gunfire event, a change sustained over 8 days. Additionally, increased gunshots led to a significant rise in the proportion of night-time vocal activity. These behavioural changes can affect forest elephant foraging and reproductive success and their interactions with vegetation, impacting forest growth and function. This study highlights the need for effective conservation strategies to protect the species and their habitats and demonstrates PAMs effectiveness in studying cryptic species in our world’s dense, highly biodiverse and life-sustaining tropical forests. This article is part of the theme issue ‘Acoustic monitoring for tropical ecology and conservation’.

The Green Band: Using Production and Catch to Judge Distortive Pressure on an Ecosystem

2025-06-12

Elizabeth A. Fulton , Keith Sainsbury , Cathy Bulman +7 more | bioRxiv (Cold Spring Harbor Laboratory)

Abstract Ecosystem based fisheries management is an increasingly accepted approach for many fisheries management agencies. Indicators and methods that can usefully support the aspiration of making ecosystem based fisheries management … Abstract Ecosystem based fisheries management is an increasingly accepted approach for many fisheries management agencies. Indicators and methods that can usefully support the aspiration of making ecosystem based fisheries management decisions on tactical time frames are slowly accumulating, but have primarily focused on biomass status and trends. We first verify that fishing can distort the cumulative distribution of connections within an ecosystem, and then show (via theoretical testing and application to four contrasting case study locations) how relating catch with production by defining an acceptable band of exploitation pressure – the “Green Band” – can help inform fisheries decision makers as to whether an ecosystem is under distortive patterns of fishing pressure that will ultimately undermine the structure of the ecosystem.

Daily changes in the tropical soundscape: the acoustic partition between birds and insects in a forest in southern Vietnam

2025-06-12

Svetlana S. Gogoleva , Igor Palko , Vadim Khaitov +2 more | Acta Oecologica

Comparing point counts, passive acoustic monitoring, citizen science and machine learning for bird species monitoring in the Mount Kenya ecosystem

2025-06-12

Ciira wa Maina , Peter Njoroge | Philosophical Transactions of the Royal Society B Biological Sciences

Biodiversity loss is a pressing challenge, with ecosystems across the world under threat from factors such as human encroachment, over exploitation and climate change. It is important to increase ecosystem … Biodiversity loss is a pressing challenge, with ecosystems across the world under threat from factors such as human encroachment, over exploitation and climate change. It is important to increase ecosystem monitoring efforts to provide actionable insights for ecosystem managers and to allow effective use of conservation resources. In this work, we compare traditional bird survey approaches using point counts with the use of autonomous recording units and citizen scientists’ data at two sites within the Mount Kenya ecosystem. We also present a new dataset of more than 20 h of recordings obtained from the Mount Kenya ecosystem and annotated by expert ornithologists, and investigate the use of large deep learning models to process these recordings. Our results are mixed, and at one site, autonomous recording units and traditional point counts yield similar conclusions when comparing relative abundance of species, while at the second site, conclusions differ. Our results indicate that citizen science is preferable to point counts and autonomous recording units in determining species lists for particular habitats. However, even with the use of multiple methods, our survey still misses rare species known to occur in the Mount Kenya ecosystem, indicating that even the use of multiple methods is not exhaustive. This article is part of the theme issue ‘Acoustic monitoring for tropical ecology and conservation’.

Why is the early bird early? An evaluation of hypotheses for avian dawn-biased vocal activity

2025-06-12

Vijay Ramesh , Pavithra Sundar , Meghana Srivathsa +1 more | Philosophical Transactions of the Royal Society B Biological Sciences

Bird species vary widely in their diurnal vocalization patterns, and the drivers of this variation are not well understood. Using passive acoustic monitoring, we examined species-specific vocal activity patterns at … Bird species vary widely in their diurnal vocalization patterns, and the drivers of this variation are not well understood. Using passive acoustic monitoring, we examined species-specific vocal activity patterns at dawn and dusk for a tropical bird community in the Western Ghats biodiversity hotspot in India. We tested whether environmental factors (e.g. signal transmission conditions, ambient light, and resource availability) and social factors (e.g. territoriality) best-explained patterns of diurnal variation in vocal activity. Overall, we found that species-specific vocal activity was significantly higher at dawn ( p < 0.05). Phylogenetic generalized least squares regressions revealed that territoriality and diet both predicted stronger dawn-biased activity. Specifically, highly territorial birds (standardized effect size (SES) = 1.20, lower donfidence interval (LCI)= 0.24, upper confidence interval (UCI) = 2.16, p = 0.01) and omnivores (SES = 0.82, LCI = −0.04, UCI = 1.68, p = 0.06) had higher levels of vocal activity at dawn. Surprisingly, we failed to find any evidence in support of environmental factors in explaining dawn-biased vocal activity. Our multi-taxon approach allowed us to assess the vocal activity patterns for an entire tropical bird community. Future research must incorporate additional geographic locations and combine visual and aural observations to better understand the drivers of diurnal variation in vocal activity. This article is part of the theme issue ‘Acoustic monitoring for tropical ecology and conservation’.

Circadian rhythms and the use of transfer learning for critically endangered crested argus Rheinardia ocellata in the Central Highlands of Vietnam: the implications for conservation

2025-06-12

Thanh Nguyen , Thinh Tien Vu , Hoa Thi Nguyen +1 more | Philosophical Transactions of the Royal Society B Biological Sciences

Understanding the circadian rhythm of the calling behaviour of wild animals can guide efforts to monitor and conserve rare and endangered species using sound. Here, we use passive acoustic monitoring … Understanding the circadian rhythm of the calling behaviour of wild animals can guide efforts to monitor and conserve rare and endangered species using sound. Here, we use passive acoustic monitoring to investigate the vocal behaviour of the crested argus ( Rheinardia ocellata ) in Kon Chu Rang Nature Reserve, Gia Lai Province, Vietnam. We had three main objectives: (i) to investigate the performance of BirdNET transfer learning for automated detection of crested argus calls; (ii) to investigate the environmental predictors of crested argus calling; and (iii) to qualitatively investigate seasonal patterns of calling. We recorded continuously for 4–5 days at 40 recording points in 2021, and at 30 points in 2023. We also recorded the calls of crested argus at four fixed points from 2022 to 2023 to explore patterns of seasonal variation. For automated detection, we found acceptable performance with only 30 high-quality training samples (F1 score = 0.70). Our top model for calling during the 24 h period only included the time category, and we found that there was peak calling activity at dawn and dusk. We found peak calling activity during March and April. Our findings can contribute to planning effective monitoring of the critically endangered crested argus. This article is part of the theme issue ‘Acoustic monitoring for tropical ecology and conservation’.

Western Australian Magpies alter the rate, but not the amplitude, of their territorial song in anthropogenic noise

2025-06-08

Grace Blackburn , Mylène Dutour , Benjamin J. Ashton +2 more | Ibis

Anthropogenic noise is considered one of the most serious forms of pollution globally and has been shown to have negative effects on the distribution, behaviour, cognition and reproductive success of … Anthropogenic noise is considered one of the most serious forms of pollution globally and has been shown to have negative effects on the distribution, behaviour, cognition and reproductive success of animal species worldwide. Among the most commonly reported impacts of anthropogenic noise are its effects on acoustic communication. Animals may adjust the rate, amplitude, duration and/or frequency of their acoustic signals to better maintain communication when anthropogenic noise is present. One of the most commonly reported vocal adjustments in noisy conditions, an increase in amplitude known as the Lombard effect, has been reported in almost all animal species tested to date. In this study, we combine behavioural focals and amplitude measurements to investigate whether female Western Australian Magpies Gymnorhina tibicen dorsalis alter the rate and amplitude of their territorial song (known as a carol) when unmanipulated levels of anthropogenic noise are present. Magpies reduced the rate at which they carolled when loud anthropogenic noise (>50 dB) was present but, contrary to our prediction, we found no evidence that magpies adjusted the amplitude of their carols under these conditions. Reduced carolling rates during anthropogenic noise may minimize the energetic expense associated with vocalizing when it is likely that such vocalizations will be masked by anthropogenic noise. However, a reduction in carolling rate may negatively affect the sociality and territoriality of magpies, as carols are important for these aspects of life. Our study adds to the growing body of literature documenting changes to the vocal behaviour of wildlife in the presence of anthropogenic noise.

Analysing vocal complexity in relation to sociality in orcas of British Columbia: An application of long-term computational passive acoustics

2025-06-06

Paul Best , Marion Poupard , Ricard Marxer +3 more | Ecological Informatics

Statistical relationship between the enclosed area and trajectory length of animal movement trajectories

2025-06-06

Atushi Ishikawa , Shouji Fujimoto , Takayuki Mizuno | Frontiers in Physics

All animals, humans included, generate closed trajectories—or loops—by repeatedly leaving and returning to the same location. In this study we statistically analyse such closed paths by measuring their total length … All animals, humans included, generate closed trajectories—or loops—by repeatedly leaving and returning to the same location. In this study we statistically analyse such closed paths by measuring their total length <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:math> and the area <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m2"><mml:mrow><mml:mi>S</mml:mi></mml:mrow></mml:math> that they enclose, and by quantifying the scaling law <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m3"><mml:mrow><mml:mi>S</mml:mi><mml:mo>∼</mml:mo><mml:msup><mml:mrow><mml:mi>L</mml:mi></mml:mrow><mml:mrow><mml:mi>α</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math> . Our data comprise GPS tracks for nine taxa archived in Movebank—common kestrel, demoiselle crane, tortoise, blue whale, reindeer, elephant, wildebeest, lion and nomadic humans—together with smartphone-based GPS logs of people moving in Urayasu, Japan. Daily loops extracted from these records reveal a two-regime geometry: for short displacements <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m4"><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mo><</mml:mo><mml:mspace width="-0.2em"/><mml:mn>5</mml:mn><mml:mi mathvariant="normal">k</mml:mi><mml:mi mathvariant="normal">m</mml:mi></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math> both humans and kestrels display nearly two-dimensional behaviour with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m5"><mml:mrow><mml:mi>α</mml:mi><mml:mo>≈</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:math> , whereas for longer distances the exponent drops to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m6"><mml:mrow><mml:mi>α</mml:mi><mml:mo>≈</mml:mo><mml:mn>1.5</mml:mn></mml:mrow></mml:math> , indicating a transition toward one-dimensional excursions. At the annual scale every species shows seasonal round-trip movement, yet the trajectory exponent diverges by taxon: nomadic humans, demoiselle cranes, tortoises and blue whales yield <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m7"><mml:mrow><mml:mi>α</mml:mi><mml:mo>≈</mml:mo><mml:mn>2</mml:mn></mml:mrow></mml:math> , wildebeest, elephants, and lions fall between 1 and 2, and reindeer approach <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m9"><mml:mrow><mml:mi>α</mml:mi><mml:mo>≈</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:math> . These results suggest that open environments such as sky, ocean or plain foster two-dimensional roaming, while strong social or environmental constraints—for example, herd mobility—compress movement toward a one-dimensional pattern. A Lévy-flight simulation that incorporates a return potential and bounds the turning angle reproduces the observed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m10"><mml:mrow><mml:mi>α</mml:mi></mml:mrow></mml:math> clusters, demonstrating that the strength of directional constraints is a key determinant of geometric dimensionality. Our findings establish the exponent <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m11"><mml:mrow><mml:mi>α</mml:mi></mml:mrow></mml:math> as a simple, quantitative metric for comparing movement patterns across species and across spatial and temporal scales.