<p>Green turtles (<em>Chelonia mydas</em>) perform ocean-crossing migrations, maintain healthy marine ecosystems, generate income through tourism, and are endangered and declining globally. For these reasons, among others, this species has been a focus of numerous research programs worldwide for almost a century. Most of these sea turtle research programs require some form of animal handling to collect the required data (e.g., tagging information or the collection of biological samples). However, this can cause stress, especially for wild animals, and that raises ethical issues. Here, I describe novel methods for assessing and mitigating the effects of handling stress on green turtles. Specifically: (1) I used a combination of animal-borne cameras and drone footage to determine how handling stress altered the post-release behavior of green turtles and (2) I used a photo-ID software to determine whether flipper scales can provide more accurate identifications than the more conventionally used facial scale patterns. </p> <p><br></p> <p>I found that turtles spent more time swimming and had shortened dive intervals in the first 30 mins after capture and attachment of a camera than in the hours that follow. Instances of socializing, foraging and resting increased over the 3-3.5 h after release. Animals recorded by drone and not captured were less likely to rest, which suggests this behavior may be a recovery response to handling and/or stress. The same animals were also more likely to socialize. When determining the accuracy of flipper or facial images for photo-ID, I found that head scales provided correct identifications 80% of the time, whereas the flipper provided correct identifications 100% of the time. This implies that researchers could use the flipper instead of more invasive tagging techniques, such as metal flipper tags or using lights to photograph the face for photo-ID, which can induce stress.</p>

Identifying individuals in historical photographs is important for preserving material culture, correcting historical records, and adding economic value. Historians, antiques dealers, and collectors often rely on manual, time-consuming approaches. While Artificial Intelligence (AI) offers potential solutions, it's not widely adopted due to a lack of specialized tools and inherent inaccuracies and biases. In my dissertation, I address this gap by combining the complementary strengths of human intelligence and AI. I introduce Photo Sleuth, a novel person identification pipeline that combines crowdsourced expertise with facial recognition, supporting users in identifying unknown portraits from the American Civil War era (1861--65). Despite successfully identifying numerous unknown photos, users often face the `last-mile problem' --- selecting the correct match(es) from a shortlist of high-confidence facial recognition candidates while avoiding false positives. To assist experts, I developed Second Opinion, an online tool that employs a novel crowdsourcing workflow, inspired by cognitive psychology, effectively filtering out up to 75% of facial recognition's false positives. Yet, as AI models continually evolve, changes in the underlying model can potentially impact user experience in such crowd--expert--AI workflows. I conducted an online study to understand user perceptions of changes in facial recognition models, especially in the context of historical person identification. Our findings showed that while human-AI collaborations were effective in identifying photos, they also introduced false positives. To reduce these misidentifications, I built Photo Steward, an information stewardship architecture that employs a deliberative workflow for validating historical photo identifications. Building on this foundation, I introduced DoubleCheck, a quality assessment framework that combines community stewardship and comprehensive provenance information, for helping users accurately assess photo identification quality. Through my dissertation, I explore the design and deployment of human-AI collaborative tools, emphasizing the creation of sustainable online communities and workflows that foster accurate decision-making in the context of historical photo identification. / Doctor of Philosophy / Identifying historical photos offers significant cultural and economic value; however, the identification process can be complex and challenging due to factors like poor source material and limited research resources. In my dissertation, I address this problem by leveraging the complementary strengths of human intelligence and Artificial Intelligence (AI). I built Photo Sleuth, an online platform, that helps users in identifying unknown portraits from the American Civil War era. This platform employs a novel person identification workflow that combines crowdsourced human expertise and facial recognition. While AI-based facial recognition is effective at quickly scanning thousands of photos, it can sometimes present challenges. Specifically, it provides the human expert with a shortlist of highly similar-looking candidates from which the expert must discern the correct matches; I call this as the `last-mile problem' of person identification. To assist experts in navigating this challenge, I developed Second Opinion, a tool that employs a novel crowdsourcing workflow inspired by cognitive psychology, named seed-gather-analyze. Further, I conducted an online study to understand the influence of changes in the underlying facial recognition models on the downstream person identification tasks. While these tools enabled numerous successful identifications, they also occasionally led to misidentifications. To address this issue, I introduced Photo Steward, an information stewardship architecture that encourages deliberative decision-making while identifying photos. Building upon the principles of information stewardship and provenance, I then developed DoubleCheck, a quality assessment framework that presents pertinent information, aiding users in accurately evaluating the quality of historical photo IDs. Through my dissertation, I explore the design and deployment of human-AI collaborative tools, emphasizing the creation of sustainable online communities and workflows that encourage accurate decision-making in the context of historical photo identification.

No description available.

Estimativas robustas de parâmetros populacionais de cetáceos são necessárias para a criação de estratégias de manejo e de conservação eficazes. Dentre os métodos comumente utilizados para estimar parâmetros demográficos, o método de captura e recaptura tem se destacado devido às suas vantagens e precisão. O objetivo deste estudo foi estimar parâmetros populacionais do boto-cinza, Sotalia guianensis, no estuário de Cananéia (25° 03\' S; 47° 55\' W), mediante o uso de modelos de captura-recaptura. O delineamento robusto de Pollock foi utilizado para estimar abundância, sobrevivência, emigração temporária e probabilidades de captura. Levantamentos de fotoidentificação sistemáticos foram conduzidos em três temporadas entre janeiro de 2015 e fevereiro de 2016. O modelo que melhor representou os dados mostrou uma população com sobrevivência constante, emigração temporária aleatória e probabilidades de captura com heterogeneidade variando no tempo e entre as estações. Foram estimados 430 (95% CI: 410-451) indivíduos no verão/2015; 384 (95% CI: 366-403) indivíduos no inverno/2015; e 414 (95% CI: 392-438) indivíduos no verão de 2016. A taxa de emigração temporária (&#947;\'\'=&#947;\') foi de 0,05 (&#177; 0,03) e a estimativa de sobrevivência aparente foi de 0,86 (&#177; 0,06). As probabilidades de captura variaram entre as temporadas e os períodos secundários, com valores médios de 0,24 (&#177; 0,02) no verão de 2015; 0,34 (&#177; 0,03) no inverno de 2015; e 0,24 (&#177; 0,03) no verão de 2016. Esses resultados sugerem que as variáveis ambientais entre as estações do ano têm pouco efeito sobre o tamanho da população local, a qual se encontra em equilíbrio e utiliza uma área ainda protegida de ameaças à sua perpetuação. / Reliable estimates of cetacean population parameters are necessary for effective management and conservation strategies. Capture-recapture methods have been commonly used to estimate demographic parameters because of their advantages and accuracy under a set of assumptions. The aim of this study was to estimate population parameters of Guiana dolphins, Sotalia guianensis, in the Cananeia estuary (25°03\' S; 47°55\' W) using capture-recapture models. The Pollock\'s robust design was used to estimate abundance, survival, temporary emigration and capture probabilities. Systematic boat-based photo-identification surveys were conducted in three seasons between Jan/2015 and Feb/2016. The best fitting model showed a population with constant survival, random temporary emigration and heterogeneous time-varying capture probabilities. Population sizes were of 430 (95% CI: 410-451) individuals in summer of 2015, 384 (95% CI: 366-403) individuals in winter of 2015 and 414 (95% CI: 392-438) individuals in summer of 2016. Temporary emigration rate (&#947;\'\'=&#947;\') was 0.05 (&#177; 0.03) and apparent survival estimate was 0.86 (&#177; 0.06). Capture probabilities varied greatly among seasons and secondary periods with mean values of 0.24 (&#177; SE 0.02) in summer of 2015, 0.34 (&#177; SE 0.03) in winter of 2015 and 0.24 (&#177; SE 0.03) in summer of 2016. These results suggest that environmental variables between seasons have little effect on the size of the local population, which is stable and uses an area that is still protected from threats.

Estimativas robustas de parâmetros populacionais de cetáceos são necessárias para a criação de estratégias de manejo e de conservação eficazes. Dentre os métodos comumente utilizados para estimar parâmetros demográficos, o método de captura e recaptura tem se destacado devido às suas vantagens e precisão. O objetivo deste estudo foi estimar parâmetros populacionais do boto-cinza, Sotalia guianensis, no estuário de Cananéia (25° 03\' S; 47° 55\' W), mediante o uso de modelos de captura-recaptura. O delineamento robusto de Pollock foi utilizado para estimar abundância, sobrevivência, emigração temporária e probabilidades de captura. Levantamentos de fotoidentificação sistemáticos foram conduzidos em três temporadas entre janeiro de 2015 e fevereiro de 2016. O modelo que melhor representou os dados mostrou uma população com sobrevivência constante, emigração temporária aleatória e probabilidades de captura com heterogeneidade variando no tempo e entre as estações. Foram estimados 430 (95% CI: 410-451) indivíduos no verão/2015; 384 (95% CI: 366-403) indivíduos no inverno/2015; e 414 (95% CI: 392-438) indivíduos no verão de 2016. A taxa de emigração temporária (&#947;\'\'=&#947;\') foi de 0,05 (&#177; 0,03) e a estimativa de sobrevivência aparente foi de 0,86 (&#177; 0,06). As probabilidades de captura variaram entre as temporadas e os períodos secundários, com valores médios de 0,24 (&#177; 0,02) no verão de 2015; 0,34 (&#177; 0,03) no inverno de 2015; e 0,24 (&#177; 0,03) no verão de 2016. Esses resultados sugerem que as variáveis ambientais entre as estações do ano têm pouco efeito sobre o tamanho da população local, a qual se encontra em equilíbrio e utiliza uma área ainda protegida de ameaças à sua perpetuação. / Reliable estimates of cetacean population parameters are necessary for effective management and conservation strategies. Capture-recapture methods have been commonly used to estimate demographic parameters because of their advantages and accuracy under a set of assumptions. The aim of this study was to estimate population parameters of Guiana dolphins, Sotalia guianensis, in the Cananeia estuary (25°03\' S; 47°55\' W) using capture-recapture models. The Pollock\'s robust design was used to estimate abundance, survival, temporary emigration and capture probabilities. Systematic boat-based photo-identification surveys were conducted in three seasons between Jan/2015 and Feb/2016. The best fitting model showed a population with constant survival, random temporary emigration and heterogeneous time-varying capture probabilities. Population sizes were of 430 (95% CI: 410-451) individuals in summer of 2015, 384 (95% CI: 366-403) individuals in winter of 2015 and 414 (95% CI: 392-438) individuals in summer of 2016. Temporary emigration rate (&#947;\'\'=&#947;\') was 0.05 (&#177; 0.03) and apparent survival estimate was 0.86 (&#177; 0.06). Capture probabilities varied greatly among seasons and secondary periods with mean values of 0.24 (&#177; SE 0.02) in summer of 2015, 0.34 (&#177; SE 0.03) in winter of 2015 and 0.24 (&#177; SE 0.03) in summer of 2016. These results suggest that environmental variables between seasons have little effect on the size of the local population, which is stable and uses an area that is still protected from threats.

Status and distribution of the Mediterranean monk seal in the northeastern Mediterranean were studied between October 2003 and December 2005. In total, 7 research cruises and 8 research visits were carried out to the region in the study period. The study was generally focused on two regions. First region was mainly around the Cilicia basin in the northeastern Mediterranean where a known Mediterranean monk seal colony (the Cilician colony) inhabits. Second region was around the Gulf of iskenderun where the population status of the monk seals was unknown.In the northeastern Mediterranean, all monk seal caves especially those used for breeding have been checked for whelping and monitored during the study period. In total, 7 pups were found including one death pup in the study period. Observations of the breeding behavior of the species indicated that, whelping also takes place in 2 new caves in addition to the 39 caves already reported for the study area in the earlier studies. Increase in the number of breeding caves showed that the breeding sites of the species has been expanded within the last 5 years. The Cilician colony size was estimated as 30 individuals in 2005. Identification catalog for each individual in the Cilician colony was prepared. Finally, population viability analysis (PVA) for the Cilician monk seal colony was carried out by evaluating the vital parameters of the species, which have been collected since 1994. This analysis was carried out for both pre-conservation phase and the post-conservation phase. In post conservation phase, the survival and fecundity rate of the Cilician colony was found as 0.976 and 0.169 respectively whereas these values were estimated as 0.902 and 0.200 respectively in pre-conservation phase. It was found that there is a 26.9% risk that the monk seal colony abundance will fall below the existing level (30 individuals) at least once during the next 20 years and there is also 0.2% risk that the monk seal colony abundance will fall below 12 at least once during the next 20 years. The risk was found as 21.7% by evaluating the status of the colony in preconservation phase. It was the first PVA study for this species, in which all the parameters used in the analysis were based on the study population, instead of the congeneric Hawaiian Monk Seal. Prior to this study, although monk seals have been frequently sighted by local people in the region, status of the Mediterranean monk seals and presence of the suitable habitats for the species in the Gulf of iskenderun was unknown. Therefore, population status of the Mediterranean monk seal in the Gulf of iskenderun and suitable habitats were investigated. In total, 30 caves were discovered and 7 of them were classified suitable for the Mediterranean monk seal. In addition, a monk seal information network was established in the region in order to gain information about the species especially when the individuals are sighted (alive, injured or death). In total, 51 sighting reports were obtained from local people via the Mediterranean monk seal information network during the study period. Since there are sampling difficulties due to critical status of the Mediterranean monk seal, alternative sampling techniques were investigated in order to find answers to questions related to the monk seal colony inhabiting in the northeastern Mediterranean. For identification of the individuals, comparison of the individuals and monitoring the individuals, 3D model construction technique from photographs was tested as an alternative photoidentification technique for the Mediterranean monk seal. It was found that at least 100 reference points were needed to construct the 3D model of the monk seal.

ABSTRACT The zebra shark Stegostoma fasciatum is an oviparous, demersal carpet shark that forms temporary aggregations and is distributed within shallow, coastal, subtropical and tropical waters of the Indo-West Pacific (IWP) region. The IWP region encompasses various densities of human habitation leading to differences in the levels of exploitation of chondrichthyan fishes, which are targeted for local consumption and export. This is reflected in the two current regional IUCN Red List classifications for zebra sharks of ‘Least Concern’ and ‘Vulnerable’. Despite the conservation concerns for zebra sharks in the vulnerable parts of their range, as well as importance within the ecotourism industry and collection for aquarium trade, little is known about this species in the wild. The aim of this thesis was to conduct the first intensive examination of population ecology in the zebra shark by: (i) investigating the population structure and environmental parameters associated with a relatively unexploited aggregation of zebra sharks in south-east Queensland, Australia; and (ii) investigating the genetic continuity between zebra shark populations in areas with differing levels of exploitation. To investigate the size and structure of the aggregation at the site The Group in south-east Queensland, photo-identification and mark-recapture methods were employed over a three year period (2003 - 2006). In total 327 individual zebra sharks were identified from 570 photographs. Numbered dart tags on 15 zebra sharks were used to confirm pigmentation patterns were unique and persistent in wild zebra sharks for up to 810 days. Pollock’s robust design resulted in an annual population estimate of 458 individuals (95% CI = 298 – 618). The mean number of zebra sharks observed on a single day was 8 (± 8 SE) and the maximum number of zebra sharks seen on a single day was 34. In total, 27% of the sharks were sighted in more than one summer aggregation period and males had greater re-capture probabilities than females. The aggregation consisted exclusively of large (>1800 mm total length) adults with an overall female sex bias of 3.8:1, though sex-ratios varied temporally. Passive acoustic telemetry techniques were employed to investigate the seasonality and residency of the sharks and the environmental parameters associated with their presence at the study site. Five VR2 acoustic receivers were deployed for a period of 21 months (December 2004 – August 2006) and recorded ten acoustically-tagged zebra sharks (seven females and three males). The sharks showed clear seasonality in their visitation patterns with greatest presence during the austral summer months of November through to February and no presence at all during the winter months from June through to October. However their presence did not coincide with peak water temperatures. Rather there appeared to be a critical minimum water temperature of approximately 22 ºC, above which zebra sharks would be present. The tagged zebra sharks displayed greater visitation during the calmest sea conditions. The sharks further displayed diel periodicity with greater during daylight hours, and may be using The Group as a resting site during the inactive diurnal period of the day. Complementing the ecological study on the aggregation, the population genetic structure of 180 zebra sharks from 13 locations throughout the IWP was investigated to test the concordance of IUCN zones with demographic units that have conservation value. A zebra shark specific microsatellite library was developed consisting of 14 polymorphic loci of which 13 were employed for the population genetic analysis along with mitochondrial ND4 sequence data. Mitochondrial and microsatellite data-sets from samples collected throughout northern Australia and south-east Asia concord with the regional IUCN classifications. However, evidence of genetic subdivision was found within these regions, including subdivision between locations connected by habitat suitable for migration. Further, parametric FST analyses and Bayesian clustering analyses indicated the primary genetic break within the IWP is not represented by the IUCN classifications but rather is congruent with the Indonesian throughflow current. This study has demonstrated that zebra sharks form a large, predictable, shallow coastal aggregation comprised entirely of mature adults as well as display high genetic subdivision in the Indo-West Pacific region with little to no recruitment into over-exploited populations from healthy populations. These findings indicate that, if zebra sharks form similar aggregations as that which occurs at The Group in regions of high fishing pressure then, without sufficient protection and management localised depletion and extirpation will eventuate for zebra shark populations in heavily-fished areas.

Um pequeno grupo de golfinhos Tursiops truncatus, presente na barra da laguna de Tramandaí, RS, vem sendo acompanhado desde 1996 quanto a seus padrões de ocorrência e associação. A partir de 2002, tal acompanhamento passou a incluir dados de bioacústica. Através da fotoidentificação, os indivíduos foram observados na área em todos os anos, o que permite caracterizá-los como residentes, embora predominem os momentos em que estão ausentes. O tamanho do grupo é mantido constante, com oito indivíduos adultos, mas o nascimento de filhotes pode aumentar temporariamente este número, com até 11 golfinhos tendo sido observados num mesmo ano. Os nascimentos registrados para as duas fêmeas do grupo ocorreram em pelo menos duas épocas do ano (outono e primavera), num intervalo de aproximadamente 2,7 anos. Apesar da menor freqüência de observação durante o período de inverno, em todas as épocas dos anos de estudo foram observados animais na área, embora tenham variado em número e grau de associação, assim como também em diferentes graus de fidelidade, onde alguns animais foram vistos mais freqüentemente que outros. Animais solitários predominaram nas observações em qualquer período. Maiores agrupamentos foram mais freqüentes no outono, e secundariamente na primavera, coincidindo com a presença dos filhotes. Nas associações predominaram as duplas, embora grupos de até sete golfinhos tenham sido registrados. Ao contrário do esperado para grupos pequenos, os índices de associação de superfície foram baixos ao longo do período analisado. Índices fortes (>0,40) ocorreram somente entre fêmeas e filhotes, mas também temporariamente (em um dia) entre outros indivíduos, caracterizando sua organização social num continuum entre diferentes extremos de associação, provavelmente adaptada às condições ambientais e sociais. Na análise do repertório sonoro do grupo, foram registrados vários tipos de sons, desde assobios até cliques de ecolocalização e sons pulsantes, estes últimos bastante vinculados à atividade de alimentação. Foram analisados 1.768 assobios, dos quais identificou-se pelo menos cinco padrões gerais de modulação da freqüência fundamental: ascendente, descendente, côncavo, múltiplo e em forma de parábola (não sendo registrados assobios com modulação constante). Estes, por sua vez, permitiram o reconhecimento de pelo menos 34 subcategorias de assobios. Os assobios ascendentes predominaram nos registros, mas os outros dois padrões mais freqüentes (parábola e múltiplo) também foram representativos. O número e tipo de assobio variaram de acordo com o contexto, onde mais de 80% dos assobios foram registrados em momentos de associação. Assobios múltiplos foram mais freqüentemente registrados em associações, principalmente na presença de fêmeas e filhotes. Durante estas interações com filhotes, houve também a predominância de assobios ascendentes, mas as emissões apresentaram um padrão bastante distinto, com longas seqüências sendo registradas e a ocorrência de vários tipos de assobios diferentes, muitas vezes sobrepostos, sugerindo combinações que podem estar relacionadas a um aumento na troca de informações entre os animais, por sua vez vinculadas à importância da comunicação entre mães e filhotes neste período. Animais solitários emitiram predominantemente um tipo específico de assobio, com contorno da freqüência fundamental semelhante a uma parábola. Esta classe apresentou os tipos mais variados, e devido a estas variações na modulação da fundamental e sua freqüência de ocorrência em animais solitários, sugere-se que nesta categoria poderiam ser encontrados os assobios assinatura dos indivíduos deste grupo. O grande número de tipos de assobios encontrados, assim como a diferença nos contextos de emissão, sugere que os animais possuem um repertório variado, onde vários sinais parecem ser ainda compartilhados entre eles. Por fim, a comparação entre métodos de extração manuais e automáticos dos parâmetros acústicos não revelou diferenças significativas, viabilizando os resultados de ambas as técnicas. / The occurrence and association patterns of a small group of dolphins, Tursiops truncatus, inhabiting the Tramandaí lagoon, RS, have been studied since 1996. The study includes bioacoustics data since 2002. The individuals were observed in that area every year through photo-identification, which characterizes them as resident, although their absence is very frequent. The size of the group is quite constant, with eight adults, but the birth of calves increases this number temporarily, being 11 the largest group size observed in one year. The births recorded for the two females of this group occurred at least twice a year (autumn and spring), with an interval of approximately 2.7 years. Although less observed in the winter, animals were present in the area, with varying degrees of association and fidelity, some animals being observed more frequently than others. Solitary animals were frequent in any period. Larger groups were most frequent in autumn and secondarily in spring, due to the presence of calves. Regarding associations, pairs of dolphins were the most frequent form, although groups of up to seven dolphins were recorded. Different from the expected for small groups, surface association indexes were low in the whole period of the study. Strong association (>0.40) occurred only between females and calves; strong associations were temporary (one day) among other individuals, characterizing their social organization as a continuum from different extremes of association, probably adapted to social and environmental conditions. In the analysis of the sound repertory of the group, various kinds of vocalizations were observed, from whistles to clicks of echolocation and burst sounds, the latter ones associated to feeding activities. A total of 1768 whistles were observed, from which five general patterns of the fundamental frequency modulation were distinguished: Ascending, descending, concave, multiple and in parabolic form. Constant modulation whistles were not recorded. The five patterns allowed distinguishing at least 34 subcategories of whistles. Ascending whistles predominate in the records, but the other two frequent patterns (parabola and multiple) were also representative. The number and kind of whistles varied according to the context, where more than 80% of them were recorded in association periods. Multiple whistles were most frequently recorded in associations, mainly between females and calves. During this interaction, ascending whistles predominated, but vocalizations presented a very distinct pattern, with long sequences and several different kinds of whistles, sometimes superimposed, suggesting combinations which might be related to the importance of the communication between female and calf in this period. Solitary animals produced a specific kind of whistle, with a parabolic form around the fundamental frequency. This class presented the most varied kinds. Due to the frequency of occurrence as well as their variations in the modulation of the fundamental frequency, it is suggested that in this category one could find the individual signatures of this group. The large number of whistle kinds and the different contexts in which they were recorded suggest that the animals have a varied repertory, where several signals are shared among them. Finally, the comparison of manual and automatic extraction methods of acoustic parameters did not show meaningful differences, thus allowing the results of both techniques.

Um pequeno grupo de golfinhos Tursiops truncatus, presente na barra da laguna de Tramandaí, RS, vem sendo acompanhado desde 1996 quanto a seus padrões de ocorrência e associação. A partir de 2002, tal acompanhamento passou a incluir dados de bioacústica. Através da fotoidentificação, os indivíduos foram observados na área em todos os anos, o que permite caracterizá-los como residentes, embora predominem os momentos em que estão ausentes. O tamanho do grupo é mantido constante, com oito indivíduos adultos, mas o nascimento de filhotes pode aumentar temporariamente este número, com até 11 golfinhos tendo sido observados num mesmo ano. Os nascimentos registrados para as duas fêmeas do grupo ocorreram em pelo menos duas épocas do ano (outono e primavera), num intervalo de aproximadamente 2,7 anos. Apesar da menor freqüência de observação durante o período de inverno, em todas as épocas dos anos de estudo foram observados animais na área, embora tenham variado em número e grau de associação, assim como também em diferentes graus de fidelidade, onde alguns animais foram vistos mais freqüentemente que outros. Animais solitários predominaram nas observações em qualquer período. Maiores agrupamentos foram mais freqüentes no outono, e secundariamente na primavera, coincidindo com a presença dos filhotes. Nas associações predominaram as duplas, embora grupos de até sete golfinhos tenham sido registrados. Ao contrário do esperado para grupos pequenos, os índices de associação de superfície foram baixos ao longo do período analisado. Índices fortes (>0,40) ocorreram somente entre fêmeas e filhotes, mas também temporariamente (em um dia) entre outros indivíduos, caracterizando sua organização social num continuum entre diferentes extremos de associação, provavelmente adaptada às condições ambientais e sociais. Na análise do repertório sonoro do grupo, foram registrados vários tipos de sons, desde assobios até cliques de ecolocalização e sons pulsantes, estes últimos bastante vinculados à atividade de alimentação. Foram analisados 1.768 assobios, dos quais identificou-se pelo menos cinco padrões gerais de modulação da freqüência fundamental: ascendente, descendente, côncavo, múltiplo e em forma de parábola (não sendo registrados assobios com modulação constante). Estes, por sua vez, permitiram o reconhecimento de pelo menos 34 subcategorias de assobios. Os assobios ascendentes predominaram nos registros, mas os outros dois padrões mais freqüentes (parábola e múltiplo) também foram representativos. O número e tipo de assobio variaram de acordo com o contexto, onde mais de 80% dos assobios foram registrados em momentos de associação. Assobios múltiplos foram mais freqüentemente registrados em associações, principalmente na presença de fêmeas e filhotes. Durante estas interações com filhotes, houve também a predominância de assobios ascendentes, mas as emissões apresentaram um padrão bastante distinto, com longas seqüências sendo registradas e a ocorrência de vários tipos de assobios diferentes, muitas vezes sobrepostos, sugerindo combinações que podem estar relacionadas a um aumento na troca de informações entre os animais, por sua vez vinculadas à importância da comunicação entre mães e filhotes neste período. Animais solitários emitiram predominantemente um tipo específico de assobio, com contorno da freqüência fundamental semelhante a uma parábola. Esta classe apresentou os tipos mais variados, e devido a estas variações na modulação da fundamental e sua freqüência de ocorrência em animais solitários, sugere-se que nesta categoria poderiam ser encontrados os assobios assinatura dos indivíduos deste grupo. O grande número de tipos de assobios encontrados, assim como a diferença nos contextos de emissão, sugere que os animais possuem um repertório variado, onde vários sinais parecem ser ainda compartilhados entre eles. Por fim, a comparação entre métodos de extração manuais e automáticos dos parâmetros acústicos não revelou diferenças significativas, viabilizando os resultados de ambas as técnicas. / The occurrence and association patterns of a small group of dolphins, Tursiops truncatus, inhabiting the Tramandaí lagoon, RS, have been studied since 1996. The study includes bioacoustics data since 2002. The individuals were observed in that area every year through photo-identification, which characterizes them as resident, although their absence is very frequent. The size of the group is quite constant, with eight adults, but the birth of calves increases this number temporarily, being 11 the largest group size observed in one year. The births recorded for the two females of this group occurred at least twice a year (autumn and spring), with an interval of approximately 2.7 years. Although less observed in the winter, animals were present in the area, with varying degrees of association and fidelity, some animals being observed more frequently than others. Solitary animals were frequent in any period. Larger groups were most frequent in autumn and secondarily in spring, due to the presence of calves. Regarding associations, pairs of dolphins were the most frequent form, although groups of up to seven dolphins were recorded. Different from the expected for small groups, surface association indexes were low in the whole period of the study. Strong association (>0.40) occurred only between females and calves; strong associations were temporary (one day) among other individuals, characterizing their social organization as a continuum from different extremes of association, probably adapted to social and environmental conditions. In the analysis of the sound repertory of the group, various kinds of vocalizations were observed, from whistles to clicks of echolocation and burst sounds, the latter ones associated to feeding activities. A total of 1768 whistles were observed, from which five general patterns of the fundamental frequency modulation were distinguished: Ascending, descending, concave, multiple and in parabolic form. Constant modulation whistles were not recorded. The five patterns allowed distinguishing at least 34 subcategories of whistles. Ascending whistles predominate in the records, but the other two frequent patterns (parabola and multiple) were also representative. The number and kind of whistles varied according to the context, where more than 80% of them were recorded in association periods. Multiple whistles were most frequently recorded in associations, mainly between females and calves. During this interaction, ascending whistles predominated, but vocalizations presented a very distinct pattern, with long sequences and several different kinds of whistles, sometimes superimposed, suggesting combinations which might be related to the importance of the communication between female and calf in this period. Solitary animals produced a specific kind of whistle, with a parabolic form around the fundamental frequency. This class presented the most varied kinds. Due to the frequency of occurrence as well as their variations in the modulation of the fundamental frequency, it is suggested that in this category one could find the individual signatures of this group. The large number of whistle kinds and the different contexts in which they were recorded suggest that the animals have a varied repertory, where several signals are shared among them. Finally, the comparison of manual and automatic extraction methods of acoustic parameters did not show meaningful differences, thus allowing the results of both techniques.

Um pequeno grupo de golfinhos Tursiops truncatus, presente na barra da laguna de Tramandaí, RS, vem sendo acompanhado desde 1996 quanto a seus padrões de ocorrência e associação. A partir de 2002, tal acompanhamento passou a incluir dados de bioacústica. Através da fotoidentificação, os indivíduos foram observados na área em todos os anos, o que permite caracterizá-los como residentes, embora predominem os momentos em que estão ausentes. O tamanho do grupo é mantido constante, com oito indivíduos adultos, mas o nascimento de filhotes pode aumentar temporariamente este número, com até 11 golfinhos tendo sido observados num mesmo ano. Os nascimentos registrados para as duas fêmeas do grupo ocorreram em pelo menos duas épocas do ano (outono e primavera), num intervalo de aproximadamente 2,7 anos. Apesar da menor freqüência de observação durante o período de inverno, em todas as épocas dos anos de estudo foram observados animais na área, embora tenham variado em número e grau de associação, assim como também em diferentes graus de fidelidade, onde alguns animais foram vistos mais freqüentemente que outros. Animais solitários predominaram nas observações em qualquer período. Maiores agrupamentos foram mais freqüentes no outono, e secundariamente na primavera, coincidindo com a presença dos filhotes. Nas associações predominaram as duplas, embora grupos de até sete golfinhos tenham sido registrados. Ao contrário do esperado para grupos pequenos, os índices de associação de superfície foram baixos ao longo do período analisado. Índices fortes (>0,40) ocorreram somente entre fêmeas e filhotes, mas também temporariamente (em um dia) entre outros indivíduos, caracterizando sua organização social num continuum entre diferentes extremos de associação, provavelmente adaptada às condições ambientais e sociais. Na análise do repertório sonoro do grupo, foram registrados vários tipos de sons, desde assobios até cliques de ecolocalização e sons pulsantes, estes últimos bastante vinculados à atividade de alimentação. Foram analisados 1.768 assobios, dos quais identificou-se pelo menos cinco padrões gerais de modulação da freqüência fundamental: ascendente, descendente, côncavo, múltiplo e em forma de parábola (não sendo registrados assobios com modulação constante). Estes, por sua vez, permitiram o reconhecimento de pelo menos 34 subcategorias de assobios. Os assobios ascendentes predominaram nos registros, mas os outros dois padrões mais freqüentes (parábola e múltiplo) também foram representativos. O número e tipo de assobio variaram de acordo com o contexto, onde mais de 80% dos assobios foram registrados em momentos de associação. Assobios múltiplos foram mais freqüentemente registrados em associações, principalmente na presença de fêmeas e filhotes. Durante estas interações com filhotes, houve também a predominância de assobios ascendentes, mas as emissões apresentaram um padrão bastante distinto, com longas seqüências sendo registradas e a ocorrência de vários tipos de assobios diferentes, muitas vezes sobrepostos, sugerindo combinações que podem estar relacionadas a um aumento na troca de informações entre os animais, por sua vez vinculadas à importância da comunicação entre mães e filhotes neste período. Animais solitários emitiram predominantemente um tipo específico de assobio, com contorno da freqüência fundamental semelhante a uma parábola. Esta classe apresentou os tipos mais variados, e devido a estas variações na modulação da fundamental e sua freqüência de ocorrência em animais solitários, sugere-se que nesta categoria poderiam ser encontrados os assobios assinatura dos indivíduos deste grupo. O grande número de tipos de assobios encontrados, assim como a diferença nos contextos de emissão, sugere que os animais possuem um repertório variado, onde vários sinais parecem ser ainda compartilhados entre eles. Por fim, a comparação entre métodos de extração manuais e automáticos dos parâmetros acústicos não revelou diferenças significativas, viabilizando os resultados de ambas as técnicas. / The occurrence and association patterns of a small group of dolphins, Tursiops truncatus, inhabiting the Tramandaí lagoon, RS, have been studied since 1996. The study includes bioacoustics data since 2002. The individuals were observed in that area every year through photo-identification, which characterizes them as resident, although their absence is very frequent. The size of the group is quite constant, with eight adults, but the birth of calves increases this number temporarily, being 11 the largest group size observed in one year. The births recorded for the two females of this group occurred at least twice a year (autumn and spring), with an interval of approximately 2.7 years. Although less observed in the winter, animals were present in the area, with varying degrees of association and fidelity, some animals being observed more frequently than others. Solitary animals were frequent in any period. Larger groups were most frequent in autumn and secondarily in spring, due to the presence of calves. Regarding associations, pairs of dolphins were the most frequent form, although groups of up to seven dolphins were recorded. Different from the expected for small groups, surface association indexes were low in the whole period of the study. Strong association (>0.40) occurred only between females and calves; strong associations were temporary (one day) among other individuals, characterizing their social organization as a continuum from different extremes of association, probably adapted to social and environmental conditions. In the analysis of the sound repertory of the group, various kinds of vocalizations were observed, from whistles to clicks of echolocation and burst sounds, the latter ones associated to feeding activities. A total of 1768 whistles were observed, from which five general patterns of the fundamental frequency modulation were distinguished: Ascending, descending, concave, multiple and in parabolic form. Constant modulation whistles were not recorded. The five patterns allowed distinguishing at least 34 subcategories of whistles. Ascending whistles predominate in the records, but the other two frequent patterns (parabola and multiple) were also representative. The number and kind of whistles varied according to the context, where more than 80% of them were recorded in association periods. Multiple whistles were most frequently recorded in associations, mainly between females and calves. During this interaction, ascending whistles predominated, but vocalizations presented a very distinct pattern, with long sequences and several different kinds of whistles, sometimes superimposed, suggesting combinations which might be related to the importance of the communication between female and calf in this period. Solitary animals produced a specific kind of whistle, with a parabolic form around the fundamental frequency. This class presented the most varied kinds. Due to the frequency of occurrence as well as their variations in the modulation of the fundamental frequency, it is suggested that in this category one could find the individual signatures of this group. The large number of whistle kinds and the different contexts in which they were recorded suggest that the animals have a varied repertory, where several signals are shared among them. Finally, the comparison of manual and automatic extraction methods of acoustic parameters did not show meaningful differences, thus allowing the results of both techniques.