Communication is a behavioral strategy used by species in the competition for survival and reproduction. Animals produce signals that are sent to receivers and occasionally transmit information that can be beneficial in a variety of contexts including avoiding predators, locating food resources, and maintaining the pair bond between partners. Researchers are interested in if auditory signals are variable and if the variability is biologically meaningful to receivers. Some species, such as siamang, sing duets as their form of acoustic communication and these duets have been studied for a variety of purposes such as investigating their structure, variability, and functionality. Siamang are a species of gibbon that combine a finite number of call units into structurally complex sequences in rule-governed ways, hereby conveying different contextual situations. Some wild gibbon species have demonstrated variation in the temporal structure of their duets and the distinctiveness in acoustic timing is unique enough for researchers to distinguish among individuals and groups based on their duet contributions. The process of coordinating and producing a uniquely timed duet could function in relation to the formation and maintenance of the pair bond. This dissertation analyzed the temporal variation and call order of wild siamang (Symphalangus syndactylus) duets that are comprised of four distinct sequences comprised of several note types. Previous research has provided detailed descriptions of captive siamang duets that include category descriptions of four call types: grunting, introduction, interlude, and great call. While these descriptions provide a general understanding of the structure of siamang duets, they can be confusing and difficult to study empirically due to their arbitrary nature. For instance, the siamang great call has been described as occurring in over 30 variants and in stable, or typical, and unstable, or atypical forms. The stable or typical form of the great call has been described to occur only after the male’s first bitonal scream. This previous research did not measure the timing of sequences through entire duets or conduct individual note analyses. Also, the most detailed investigations of siamang duets were conducted with captive animals and therefore wild siamang duets have not been quantitatively analyzed. This dissertation research measures the temporal variation of wild siamang duet call types, and the call order of individual notes in the US-II phrase. The findings will provide a more objective description of the siamang duet as well as determine if it has a more stereotyped or flexible nature. Also, in the wake of globalization, duets and other behaviors (such as travel) could be sensitive to anthropogenic disturbances. So, I am interested in how wild siamang might be impacted by human presence. The three main objectives of this dissertation are: 1) document the temporal variation in the call types of wild siamang; 2) document variation in the call order of wild siamang US-II phrases; and 3) document how wild siamang travel is impacted by anthropogenic noise. The study was conducted at 4 remote field sites in northern Sumatra, Indonesia from August 2017 through May 2018. With the assistance of a research team, I recorded acoustic and behavioral data from 10 siamang groups and two individual females. I collected acoustic data using a combination of autonomous recording units and handheld recording devices while following the study subjects on foot. I marked GPS points during behavioral scans and conducted experimentally induced noise playback experiments. I analyzed the audio data with the software program Raven Pro 1.6 and spectrograms were produced with a 512-point (11.6 ms) Hann window (3 dB bandwidth = 135 Hz), with 50% overlap and a 512-point DFT, yielding time and frequency measurement precision of 2.9 ms and 43.1 Hz. I conducted statistical testing in R Studio Version 1.3.959 in conjunction with the statistics lab at Southern Illinois University. In Chapter 3, I performed multilevel regression analysis in the form of a Generalized Linear Mixed Model (GLMM) in order to investigate temporal variation the time spent singing call types (grunting, introduction, interlude, and great call) accounting for differences between songs, groups, and field sites. I used a Bayesian hierarchical model to avoid calculating estimates using data with repeated and imbalanced sampling, and explicitly model variation within individuals, between songs, between groups, and field sites. In Chapter 4, I used the Levenshtein Distance (LD) method for investigating structural variation in the call order of US-II phrases in the siamang duet. The LD method is a quantitative technique for measuring the similarity of sequences and to quantify the differences between strings of data. In Chapter 5, I used the Friedman test to compare the means of distances traveled in 5-minute intervals in the following conditions: pre-playback, cicada (control), traffic, jackhammer, and music. I used post hoc tests with Bonferroni correction to analyze the pairwise comparisons of the five experimental conditions. Overall, the results suggest support of previous studies on the variability of the gibbon duet and animal travel in response to noise. In Chapter 3, I found some temporal variation in call types to exist at all levels of the modeling but only statistically significant when comparing the field sites of Ketambe and Kutapanjang. Relating to the functionality of total call duration, I did not find significant differences in the behavioral categories before or after any of the calls regardless of their total duration. In Chapter 4, I found US-II phrases are not as stereotyped as previous descriptions have suggested. The mean LD distances were higher than those compared by other duetting primates. Also, the results from one-way ANOVA and Games-Howell Post Hoc Testing showed significant mean differences between groups. In Chapter 5, I found siamang are impacted by noise as they traveled further after the anthropogenic noise playback experiments compared to pre-playback travel. However, the pairwise comparisons were not statistically significant and therefore I could not determine which noise condition caused the change in travel distance. Collectively, the results of this dissertation suggest that there is considerable variability in both wild siamang call types and call order in a previously described stereotyped phrase, and that wild siamang travel away is impacted by introduced anthropogenic noise. What this contributes to the field of vocalization studies is further support that precise measurement of song parameters gives a better understanding of song structure than somewhat arbitrary written descriptions. It is important to have descriptions of notes produced in songs, but to understand how those notes relate to each other, an individual note analysis and rigorous statistical methodology is necessary. The variation found in this dissertation could be due to the unique siamang response to their partner’s timing in the process of forming the pair bond. But as the siamang duet is thought to have multiple functions, the temporal variation could also be transmitting other information such as individual and group identity while functioning in territorial defense. In addition, anthropogenic noise caused the animals to change their travel behavior and this suggests it could be harmful if faced on a regular basis. Anthropogenic noise can be detrimental if it occurs in home ranges of species that are territorial and facing shrinking habitats due to continued human encroachment. In order to understand if these findings are biologically meaningful and to have firmer conclusions, future long-term studies will need a larger data set over longer periods of time. It is also important to have a larger data set and compare more siamang groups that live in various noise levels and measure variables such as caloric intake, daily travel, copulations, and number of offspring.

Methods for collecting behavioral audiograms are often time consuming and require trained, captive subjects. It is more practical to measure hearing sensitivity using electrophysiological methods, such as auditory evoked potential (AEP) testing, in which electrodes measure action potentials in response to acoustic stimuli. These data can be collected in a matter of hours. However, results should be verified through behavioral testing. Current knowledge of marine turtle auditory abilities is based on a few electrophysiological tests. The purpose of this study was to collect and compare behavioral and auditory evoked potential audiograms in a captive adult loggerhead turtle (Caretta caretta). The behavioral audiogram was collected using a go/no-go modified staircase method utilizing 2-second pure-tone stimuli. AEP thresholds were measured underwater using subdermal electrodes placed beneath the frontoparietal scale, dorsal to the midbrain. Action potentials were measured in response to 50 ms tonal stimuli and averaged over a maximum of 1,000 responses. Evoked potential testing yielded thresholds from 100 - 1131 Hz with peak sensitivity at 200 and 400 Hz (110 dB re 1 µPa). Behavioral testing yielded thresholds from 50 - 800 Hz with peak sensitivity at 100 Hz (98 dB re 1 µPa). Behavioral thresholds averaged 8 dB lower than AEP thresholds from 100 to 400 Hz and 5 dB higher at 800 Hz. Results indicate that behavioral and evoked potential techniques are suitable for determining marine turtle hearing sensitivity. AEP testing is a good alternative when dealing with wild or untrained animals and when time is a critical factor.

Over the past century, populations of North American grassland songbirds have declined sharply as a consequence of habitat destruction. Alberta’s mixed-grass prairie constitutes Canada’s largest remaining tract of native grassland. However, this region has recently undergone a rapid expansion of conventional oil and natural gas development, and few studies have documented its effects on songbird nesting success. During the 2012-2014 breeding seasons, I monitored 813 nests of grassland songbirds located at sites that varied with respect to presence/absence, distance from, and types of oil and gas infrastructure (pump jacks, screw pumps, compressor stations) and gravel roads. Nest survival was significantly lower at infrastructure sites relative to controls for both Savannah sparrow and vesper sparrow. Additionally, vesper sparrow nest density was greater within 100 m of structures. These findings suggest that habitat disturbance caused by infrastructure may result in increased frequencies of nest predation at multiple spatial scales. / February 2016

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-03-31T15:07:28Z No. of bitstreams: 1 sarahstutzreis.pdf: 2710665 bytes, checksum: 3e112b0640b97d744e46b7134c227148 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T02:58:46Z (GMT) No. of bitstreams: 1 sarahstutzreis.pdf: 2710665 bytes, checksum: 3e112b0640b97d744e46b7134c227148 (MD5) / Made available in DSpace on 2016-04-24T02:58:46Z (GMT). No. of bitstreams: 1 sarahstutzreis.pdf: 2710665 bytes, checksum: 3e112b0640b97d744e46b7134c227148 (MD5) Previous issue date: 2013-02-01 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os delfinídeos exibem grande plasticidade de sinais acústicos e são capazes de adequar suas emissões sonoras frente à diferentes circunstâncias. Atualmente, a poluição sonora dos oceanos constitui uma ameaça aos cetáceos e esta questão tem sido pouco estudada em relação ao boto-cinza (Sotalia guianensis). Logo, seus sinais acústicos representam um aspecto biológico importante a ser compreendido. Neste contexto, este estudo visou caracterizar o repertório sonoro e investigar o ambiente acústico dos botos-cinza que utilizam a baía de Benevente, ES. As gravações foram realizadas utilizando-se hidrofone Cetacean Research C54XRS acoplado a gravador digital Fostex FR-2 LE gravando a 96kHz/24bits. Os dados coletados entre dezembro de 2011 e julho de 2012 totalizaram 27horas e 55minutos de esforço de gravação. Foram analisados 69 assobios, 42 sons pulsantes explosivos e 33 cadeias de cliques. Dentre os assobios o contorno mais comum foi o do tipo ascendente (N=37; 53%), seguido pelos tipos ascendente-descendente (N=15; 22%), múltiplo (N=13; 19%). A frequência fundamental dos assobios variou entre 3,51 kHz e 37,56 kHz. Os parâmetros analisados foram: duração, pontos de inflexão, frequências inicial, final, mínima, máxima, variação e frequências a 1/4, 1/2 e 3/4 da duração. A duração média destes sinais foi 0,298 segundos (DP= 0,147). Quanto aos sons pulsantes explosivos, o sinal do tipo “bray call” (N=36) foi mais comum e mais longo que o “buzz sound”(N=6). Estes dois tipos ocorreram imediatamente após ou próximos a cliques de ecolocalização. Em relação a estes, 33 cadeias foram analisadas e estas apresentaram 36,45 cliques (DP= 43,47) e 11,404 (DP= 21,226) segundos de duração, em média. Os intervalos entre cliques (ICI) duraram 0,308s (DP= 0,301), em média. Verificou-se dois padrões temporais distintos entre os ICIs: 81% (N=946) dos intervalos duraram entre 0,001 e 0,400 segundos e os 19% (N=224) restantes duraram entre 0,401 e 1,246 segundos. A maioria das médias dos parâmetros de frequência dos assobios foram superiores aos valores verificados em estudos com S. guianensis ao sul da área de estudo e inferiores aos valores de populações ao norte. Isto pode estar relacionado aos diferentes limites de frequência destes trabalhos e/ou à hipótese de que a frequência aumenta do sul para o norte. Os sons explosivos observados foram verificados anteriormente para S. guianensis e outros odontocetos. Além de apresentarem função social, também podem estar relacionados à obtenção de presas. A distribuição dos valores de ICI em padrões temporais distintos já foi observada para S. guianensis e outras espécies de golfinhos, podendo representar as distintas funções dos cliques de ecolocalização. O boto-cinza ocorreu em áreas onde existia um ruído antropogênico de baixa frequência. Na presença deste ruído ocorreram alterações no comportamento acústico que possivelmente expressam uma tentativa de compensar o efeito de mascaramento para manter a comunicação eficiente em um ambiente acústicamente poluído. / The Delphinidae exhibits great plasticity of acoustic signals and adapts their sound emission according to circumstances. Currently, ocean noise pollution is a threat to cetaceans and this issue has not been well studied in relation to the estuarine dolphin (Sotalia guianensis). Therefore, their acoustic signals represent an important biological aspect to be understood. In this context, this study aimed to characterize the sound repertoire and investigate the acoustic environment of estuarine dolphin in Benevente Bay, ES, Brazil. The recordings were performed using hydrophone Cetacean Research C54XRS coupled to digital recorder Fostex FR-2 LE recording at 96kHz/24bits. Data collected between December 2011 and July 2012 totaled 27 hours and 55 minutes of effort recording. We evaluated 69 whistles, 42 burst sounds and 33 clicks’ train. Among the whistles contour the most common type was ascending (N = 37, 53%), followed by ascending-descending (N = 15, 22%) and multiple (N = 13, 19%) types. The fundamental frequency of whistles ranged between 3.51 kHz and 37.56 kHz. The frequency parameters analyzed were: start, end, minimum, maximum, range and frequencies at 1/4, 1/2 and 3/4 of the duration. The duration and inflection points were also analyzed. The average duration of whistles was 0.298 second (SD = 0.147). About the burst pulse sounds the sign "bray call" (N = 36) was more common and longer than the "buzz sound" (N = 6). These two types occurred immediately after or near echolocation clicks. On these, 33 trains were analyzed and presented 36.45 (SD = 43.47) clicks and 11.404 (SD = 21.226) seconds, in average length. The interval between clicks or “Inter-click interval” (ICI) lasted 0.308 (SD = 0.301) seconds in average. It was also found two distinct temporal patterns for ICIs: 81% (N = 946) intervals lasted between 0.001 and 0.400 seconds and 19% (N = 224) lasted between 0.401 and 1.246 seconds. Most of the frequency parameters’ average from whistles were higher than those observed in studies with S. guianensis at south of the study area and lower than populations at north. This could be related to different frequency limits and/or the assumption that the frequency increases from south to north. The burst sounds observed were previously cited for S. guianensis and other odontocetes. Besides presenting a social function, these sounds may be related to obtaining prey. The distribution of the ICIs’ values in distinct temporal patterns was also reported for S. guianensis and other species of dolphins, which may represent the different functions of echolocation clicks. The estuarine dolphin occurred in the presence of a low-frequency anthropogenic noise. On this occasion there was a change in the acoustic behavior that possibly expresses an attempt to compensate for the effect of masking to maintain effective communication in an acoustically polluted environment.

Pervasive growth in industrialization and advances in technology now exposes much of the world to anthropogenic night light and noise (ANLN), which pose a global environmental challenge in terrestrial environments. An estimated one-tenth of the planet’s land area experiences artificial light at night — and that rises to 23% if skyglow is included. Moreover, anthropogenic noise is associated with urban development and transportation networks, as the ecological impact of roads alone is estimated to affect one-fifth of the total land cover of the United States and is increasing in space and intensity. Existing research involving impacts of light or noise has primarily focused on a single sensory stressor and single species; yet, little information is known about how different sources of sensory stressors impact the relationships within tightly-knit and complex systems, such as within plant-pollinator communities. Furthermore, ANLN often co-occur, yet little is known about how co-exposure to these stressors influences wildlife, nor the extent and scale of how these stressors impact ecological processes and patterns. In Chapter 1, we had two aims: to investigate species-specific responses to artificial night light, anthropogenic noise, and the interaction between the two by using spatially-explicit models to model changes in abundance of 140 of the most prevalent overwintering bird species across North America, and to identify functional traits and contexts that explain variation in species-specific responses to ANLN stressors with phylogenetically-informed models. We found species that responded to noise exposure generally decreased in abundance, and the interaction with light resulted in negative synergistic responses that exacerbated the negative influence of noise among many species. Moreover, the interaction revealed negative emergent responses of species that only reacted when both ANLN were presented in combination. The functional trait that was the most indicative of avian response to ANLN was habitat preference. Specifically, species that occupy closed habitat were less tolerant of both sensory stressors compared to those that occupy open habitat. Species-specific responses to ANLN are context-dependent; thus, knowing the information that regulates when, where, how, and why sensory pollutants influence species will help management efforts effectively mitigate these anthropogenic stressors on the natural environment. In Chapter 2, using field-placed light manipulations at sites exposed to a gradient of skyglow, we investigated the influence of direct and indirect light on the yucca-yucca moth mutualism by quantifying chaparral yucca (Hesperoyucca whipplei) fruit set and the obligate moth (Tegeticula maculata maculata) larval density per fruit. Although many diurnal insects are thought to exhibit minimal phototaxis, we show that direct light attracted adult moths and incited higher pollination activity, resulting in an increase in fruit set. However, larval recruitment decreased with elevated light exposure and the effect was strongest for plants exposed to light levels exceeding natural moonlit conditions (> 0.5 lux). Contrarily, increases in ambient skyglow resulted in an increase in both fruit set and larva counts. Our results suggest that plant-pollinator communities may respond in complicated ways to different sources of light, such that novel selection pressures of direct and indirect light have the potential to benefit or disrupt networks within complex diurnal plant-pollinator communities, and ultimately alter the biodiversity reliant on these systems. By analyzing pervasive stressors across a continental-wide scale, we revealed considerable heterogeneity in avian responses to light and noise alone, as well as the interaction between them. Based on overall responses to the interaction between light v and noise, we suggest management efforts should focus on ameliorating excessive noise for overwintering bird species, which should decrease the impact from synergistic responses, as well as the negative impact from noise alone. There is still much to learn about responses to these stressors and smaller-scale studies should take our approach of systematically assessing interaction responses to ANLN. Moreover, our small-scale study revealed both local sources of direct light and skyglow impact the recruitment for both yucca moths and their reciprocal plant hosts. However, it is still unknown if or why other diurnal pollinators experience positive phototaxis, and whether direct lighting influences the physiology, behavior, or multiple factors relating to reproduction and fitness. Correspondingly, it is unknown if the novel selection pressures of direct and indirect light are disrupting complex diurnal plant-pollinator communities. Future research on artificial night light will need to investigate the intricate responses of diurnal pollinators to both direct and indirect light that will identify concrete mechanisms relating to physiological or behavioral susceptibility and inform predictions on how wide-spread communities will shift with this global driver of emerging change.

No description available.

Made available in DSpace on 2014-12-17T15:36:39Z (GMT). No. of bitstreams: 1 MarcosRRS_TESE_2red.pdf: 2914202 bytes, checksum: 607aa226333ce661d0e57d380f43b9e9 (MD5) Previous issue date: 2012-08-07 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The acoustic ecology concept involve the relation between the live organisms and their sound environment and is applied in the present work to study the context in which the humpback whale (Megaptera novaeangliae) singing behavior, known as the most complex display in the nature, occurred in the northeastern Brazilian coast, outside the core area of Abrolhos Bank, between 2005 and 2010.I analyze the singer male occurrence , their spatial distribution and probable relations with oceanographic features, such as depth, tide regimen and moon phases. I also describe the acoustic structure and temporal variation of the singing behavior, based on song frequency and time measurements outside the Abrolhos Bank, and further compare the song complexity, registered in the same period, between Abrolhos Bank (16?- 19? S, 37?- 39? W) and the adjacent North Coast, herein considered from Itacar? (14? S, 38? W) to Aracaju (11? S, 37? W). Additionally, I look for describe and analyze anthropogenic noise sources in the marine environment of the study area, produced by the oil industry as well as by the whale watching operation, relating their frequencies to the acoustic niche utilized by the humpbacks. The results indicated a great plasticity in the singing behavior, evidenced by the occurrence of singer males in diverse social structures, from solitary individuals to other groups, even containing females and calves, as well as by the diversity which compound the song, when compared between two regions inside the same breeding area, which present distinct oceanographic characteristics. The singer male distribution may be related with the continental shelf extent along the study area. The anthropogenic noise presented frequency range, amplitude and sound intensity in potential to interfere acoustically in the singing behavior of the species, may resulting in disturbance during the breeding season in the Brazilian coast. Implications about the obtained results in the humpback whale mating system are discussed. In this way, I pretend to contribute with the acoustic ecology subject and provide information to subsidize humpback whale conservation / O conceito de ecologia ac?stica envolve a rela??o entre os organismos vivos e o seu ambiente sonoro e ? aplicado no presente trabalho para estudar o contexto no qual ocorreu o comportamento de canto da baleia jubarte (Megaptera novaeangliae), considerado o mais complexo comportamento reprodutivo (display) da natureza, na costa nordeste do Brasil, fora da concentra??o reprodutiva do Banco de Abrolhos, entre os anos de 2005 e 2010. Analiso a ocorr?ncia de machos cantores em diferentes estruturas de grupo, sua distribui??o espacial e prov?veis rela??es com fatores oceanogr?ficos, como profundidade, regime de mar?s e fases da lua. Tamb?m descrevo a estrutura ac?stica e a varia??o temporal do comportamento de canto, baseado em medi??es de frequ?ncia e tempo dos cantos, fora do Banco de Abrolhos, al?m de comparar a complexidade do canto, registrada no mesmo per?odo de estudo, entre o Banco de Abrolhos (16?- 19? S, 37?- 39? W), e a Costa Norte adjacente, aqui considerada desde Itacar? (14? S, 38? W) a Aracaj? (11? S, 37? W). Ainda busco descrever e analisar as fontes de ru?dos antropog?nicos no ambiente marinho da ?rea de estudo, produzidos pela atividade de explora??o de petroleo e g?s e tamb?m pelo turismo de observa??o de baleias, relacionando-os com o nicho ac?stico utilizado pela jubarte. Os resultados indicaram uma grande plasticidade no comportamento de canto, evidenciado pela ocorr?ncia dos cantores em diversas estruturas sociais, de indiv?duos solit?rios a grupos contendo outros animais, inclusive f?meas com filhotes, bem como pela diversidade que comp?e o canto da esp?cie, quando comparado entre duas regi?es dentro da mesma ?rea de reprodu??o, como o Banco de Abrolhos e a Costa Norte, que apresenta caracter?sticas oceanogr?ficas distintas. A distribui??o dos machos cantores parece estar relacionada com a extens?o da plataforma continental na ?rea de estudo. Os ru?dos antropog?nicos produzidos demonstraram uma faixa de frequ?ncias, amplitude sonora e intensidade capazes de interferir acusticamente no comportamento de canto da esp?cie, podendo resultar em dist?rbios durante o per?odo de reprodu??o da esp?cie na costa brasileira. Implica??es sobre os resultados obtidos na teoria do sistema de acasamento da esp?cie s?o discutidas. Dessa forma, pretendo contribuir com o tema da ecologia acustica e gerar informa??es que subsidiem a conserva??o da baleia jubarte

L’urbanisation grandissante est certainement à l’heure actuelle parmi les phénomènes à l’origine des changements les plus importants induits par l’homme sur notre planète, et soulève donc de nombreuses questions concernant les conséquences d’une telle perturbation de l’environnement sur la biodiversité. La vie urbaine est souvent caractérisée par des conditions jugées comme contraignantes (fragmentation, dégradation et perte d’habitats, pollutions chimiques, sonores et lumineuses accrues, etc.) pouvant avoir des effets néfastes sur les vertébrés. Cependant, les mécanismes par lesquels l’urbanisation affecte la faune sauvage sont encore très mal compris. Dans ce contexte, l’objectif central de ce doctorat est d’améliorer notre compréhension de l’influence de l’urbanisation sur les espèces de vertébrés évoluant dans les environnements urbains. Pour cela, nous avons exploré, d’une part, l’influence globale de l’urbanisation, et d’autre part, l’impact spécifique de certaines contraintes caractéristiques des milieux urbains (pollution par les métaux lourds et pollution sonore) sur les passereaux, en utilisant une approche fonctionnelle intégrant notamment des études éco-physiologiques et éco-toxicologiques. Ainsi, nous avons mis en évidence que les passereaux urbains ne sont pas contraints énergétiquement par leur environnement pendant leur vie adulte, mais qu’en revanche, les conditions fortement modifiées des milieux urbains pourraient contraindre les individus pendant leur développement. De plus, nous avons montré que l’urbanisation est effectivement associée à une contamination par les métaux lourds plus importante, et surtout que des niveaux plus élevés de ces contaminants sont associés à des niveaux de corticostérone plus élevés (degrés de stress plus importants). Enfin, l’étude expérimentale de l’impact de la pollution sonore sur des paramètres très souvent négligés jusque-là (développement, physiologie, comportement anti-prédateur), nous a permis de montrer que le bruit d’origine anthropique pouvait avoir des effets particulièrement complexes sur le développement des vertébrés avec de possibles conséquences à long terme. L’ensemble de ces travaux soulignent l’importance d’évaluer l’impact des perturbations d’origine anthropique sur le développement phénotypique des individus afin de mieux comprendre l’influence de l’environnement urbain sur les populations de vertébrés. / Consistent expanding urbanization is certainly among the most important human-induced environmental changes facing our planet today, and thus raises important questions regarding the consequences of such environmental disturbance on biodiversity. Urban life is often characterized by constraining environmental conditions (e.g., fragmentation, degradation and loss of habitats, increased noise, light, and chemical pollutions) that can have detrimental effects on wild vertebrates. However, the mechanisms through which urbanization affects wildlife are still poorly understood. In this context, the main objective of this doctoral research is to improve our understanding of the influence of urbanization on vertebrate species that are able to live in urban environments. To this end, we explored both the global influence of urbanization and the impact of specific factors associated with urban life (heavy metals and noise pollutions) on passerine birds, using a mechanistic approach including eco-physiological and eco-toxicological studies. We demonstrated that urban passerines are not energetically constrained by their environment during their adult life, but conversely, that the altered environmental conditions of urban environments could constrain individuals during their development. Furthermore, we showed that urbanization is indeed associated with an increased heavy metal contamination, and most importantly, that higher levels of these contaminants are related to higher corticosterone levels (i.e., elevated stress levels). Finally, using an experimental approach to study the impact of noise pollution on several parameters that have often been overlooked (development, physiology, anti-predator behaviour), we showed that anthropogenic noise can have particularly complex effects on vertebrate’s development, with possible life-long consequences for developing birds. Overall, our results emphasize the importance of investigating the impact of human-induced environmental changes on the phenotypic development of individuals to better understand the influence of urban environments on vertebrate populations.

The main aim of this thesis was to investigate the occurrence of dolphins in Pacific waters adjacent to the Panama Canal in the context of biological, temporal and spatial factors. Acoustic data were collected at 101 sites at a range of distances and depths from the shipping region. Data were collected between March 2010 and April 2011 in a diurnal cycle over a total of 114 recording days. Received sound levels were split into 1/3 Octave bandwidths to study variation in sound pressure levels and then converted to spectrum density levels to show the sound components of the background noise in this region. Generalised Linear Models were used to relate dolphin whistle detections to temporal, spatial, environmental and acoustic variables. The major sources of background noise were biological noise from soniferous fish and snapping shrimp and anthropogenic noise from vessels characterised by mid to high frequencies produced by artisanal fishing boats. There was monthly and diurnal variation with some locations characterised by loud sounds in the mid to high frequencies at night. Whistle characteristics analysis revealed that the frequencies and range of the whistles were different to those previously reported under similar conditions. Whistles varied diurnally and in the presence of fish chorus and fishing boats. The study highlights a strong correlation between fish choruses and whistle detection. Temporal and spatial models showed that whistle detections varied monthly and in relation to fish noise and small vessel engine noise. Dolphins were distributed throughout most of the study area; however, whistle detections varied with distance from the coast. The results provide new knowledge about background noise composition in this region and provide the first information on the ecology of dolphin whistles in relation to this background noise, especially to fish chorus.