Bat populations in the eastern United States are currently declining at unprecedented rates as a result of habitat loss, commercial wind energy development, and white-nose syndrome. Effective conservation of these declining populations requires knowledge of several aspects of summer and winter ecology, including daytime habitat use (day-roost selection and social behaviors), nocturnal habitat use (foraging habitat selection, prey selection, and prey abundance), and winter hibernation (torpor) patterns. This dissertation addresses these questions for Rafinesque’s big-eared bat (Corynorhinus rafinesquii), a species of conservation concern in the southeastern United States. Kentucky represents the northern edge of the range of Rafinesque’s big-eared bat, and summer and winter behaviors in Kentucky are likely to differ from what has been observed in southern portion of the range, where available habitats and climate are different. My research occurred in two study areas in Kentucky, Mammoth Cave National Park in central Kentucky, and the Ballard Wildlife Management areas in western Kentucky. This dissertation includes all of the work done in western Kentucky, where I radio-tagged 48 adult big-eared bats and documented daytime and nighttime habitat use. Also included is a portion of the work done in central Kentucky, focusing on hibernation patterns of 14 adult big-eared bats radio-tagged during the winter at Mammoth Cave. Data disseminated in this dissertation provide insights into the summer and winter ecology of Rafinesque’s big-eared bat in Kentucky, and can be used to manage populations threatened by habitat loss and white-nose syndrome.

Les PCB (polychlorobiphényles) sont des molécules connues pour leur longue demi-vie et leur forte liposolubilité qui conduisent à une bioaccumulation et une bioamplification dans les réseaux trophiques, menant à un potentiel risque pour les prédateurs de haut niveau tel que l’Homme. De plus, il a été démontré que leur affinité avec les composés lipidiques conduisaient à une transmission de la femelle à l’œuf chez les poissons. Dans ce contexte, et comme d’autres travaux ont déjà montré des effets des PCB sur la physiologie et le comportement d’animaux contaminés de différentes façons, nous avons observé les effets de ces molécules chez deux espèces, la sole commune et le poisson zèbre. La contamination a été réalisée via l’alimentation avec deux mélanges de PCB et deux concentrations qui correspondent à des situations environnementales, en termes de dose ou de choix et de proportion des congénères retenus. La dose la plus haute est équivalente à celle mesurée dans de la chair de molusques en baie de Seine et la dose intermédiaire à celle mesurée en estuaire de Loire. Les soles contaminées ont montré une diminution du niveau d’activité locomoteur après 30 jours (j) de contamination et une altération des capacités cryptiques après 60 j de contamination. Les poissons zèbre contaminés ont montré une augmentation de l’activité locomotrice après 250 j de contamination. La génération issue de cette génération de poisson zèbre contaminée a elle aussi montré une augmentation de l’activité locomotrice au stade larvaire et adulte. Chez les adultes, cela s’est traduit par une diminution de l’utilisation de la zone de fond des bacs et une augmentation du nombre de transition de zones, ce qui s’explique par une perte d’inhibition comportementale. Dans les deux cas, les phénotypes comportementaux observés chez les groupes PCB sont associés à une altération de la locomotion dans le sens d’une baisse d’activité pour une espèce placide comme la sole et dans le sens de l’augmentation pour une espèce mobile comme le poisson zèbre. / Because of their long biological half-life and high liposolubility, PCBs (polychlorinated biphenyls) are bioaccumulated and biomagnified through food chains over a wide range of trophic levels, leading to a potential risk for high trophic level predators including humans. Further, due to their binding with lipids, a demonstrated maternal transfer to eggs exists in fish. In this context, and since field analyses and experimental exposures have established links between PCBs exposure and alterations in physiology and behaviour of contaminated animals, we have examined the effects in both common sole and zebrafish species exposed through diets to two PCBs mixtures at two doses mimicking known environmental contamination levels and congener composition. The highest dose was equivalent to that found in molluscs flesh in the Seine Estuary and the intermediate dose was equivalent to that found in the Loire estuary. Contaminated soles showed a decreased locomotor activity level after 30 days (d) of contamination and altered cryptic abilities after 60 d of contamination. Contaminated zebrafish showed an increased locomotor activity level after 250 d of contamination. The offspring obtained from this contaminated generation of zebrafish showed an increase in swimming activity in larvae which was maintained in adults. In adults, this was associated with a decrease in tank bottom section occupancy and with an increase in the number of zone transition which may be due to a loosening of homebase behaviour and/or a loss of behavioural inhibition. In both cases, behavioural phenotypes observed in PCBs groups can be related to a disruption in locomotion activity towards decreased levels for a placid species like common sole and increased levels for a mobile species like zebrafish.

Bayou St. John (BSJ) and City Park Lakes and Lagoons (CPLL) are urban waterways in New Orleans, Louisiana. I studied habitat selection of red drum in BSJ, and fish assemblage change in BSJ and CPLL over 40 years. Temperature was found to be the best predictor of red drum habitat selection in Bayou St. John, while salinity and change in depth also were found to be good predictors for certain sites. Potential prey item abundance did not appear to influence habitat selection. Using data from 1971 – 2010, nearshore habitats in CPLL were affected by Hurricane Katrina, but have sense recovered and nearshore habitats in BSJ were found to have decreased diversity. Pelagic habitats in both areas were found stable across 40 years. Since 2006, nearshore assemblages were similar for CPLL and BSJ with a decrease in fishes from Order: Cyprinodontiformes and an increase in other fishes seen across years.

The butterflies in the genus Hamadryas are popular and noticeable representatives of the Neotropical Lepidoptera fauna. After a thorough taxonomic revision, 20 species were acknowledged within the genus, however no hypothesis of their phylogenetic relationship was proposed. The present dissertation provides a step further into the understanding of this fascinating group of butterflies not only by proposing the first phylogenetic hypothesis for the genus based on morphological and molecular data, but also by exploring for the first time in a group of butterflies the potential effect of venation associated with an specific behaviour on wing shape. Furthermore, this dissertation provides testable evolutionary hypotheses about the pattern of change for some of their most interesting natural history characters such as sound production and sexual dimorphism. The dissertation is organized in three chapters that can be visualized as manuscripts ready for publication; the first of these being already published (Garzón-Orduña, 2012).

Quantifying the impacts of restoration on coastal waterways is crucial to understanding their effectiveness. Here, I look at the impacts of multiple restoration projects on urban waterways within the city limits of New Orleans, LA, with an emphasis on the response of fishes. First I report the effects of two projects designed to improve exchange down estuary on the hydrologic characteristics of Bayou St. John (BSJ). Within BSJ, flow is dominated by subtidal wind driven processes. Removal of an outdated flood control structure did not appear to alter exchange in BSJ, but removal combined with sector gate openings did. I also refined a three dimensional hydrodynamic model of this system to have accurate predictions of velocity and elevation. Temperature and salinity were difficult to constrain with this model. Solutions of this model were used to compare flow metrics, along with linearly interpolated temperature, and other variables to Red Drum (Sciaenops ocellatus) activity and movement patterns. Relationships between Red Drum activity and velocity suggested a response to subtidal, wind driven flow. Overall, high Sedentariness, a measure of inactivity, was found suggesting high levels of site fidelity. Higher mean Sedentariness during the night was also found. I also used a pseudo-BACI design to analyze the fish assemblage response to removal of an outdated flood control structure and the impacts of sector gate openings on fish guild species richness in BSJ. Limited differences were found when comparing fish assemblages before and after removal, but these differences were likely due to a decrease in salinity not restoration efforts. No significant differences in Freshwater or Estuarine fish guild species richness was observed for any of the control or impact sites. Marine fish species richness was found to be higher immediately following sector gate openings at the site closest to the structure, suggesting an initial pulse of young marine organisms is provided via these events. The findings here can be used to optimize management of exchange flow in coastal impounded waterways.

Três experimentos foram realizados sobre o uso de ferramentas para quebra de frutos encapsulados por macacos-prego (Cebus apella) em condição de semi-liberdade no Parque Ecológico do Tietê. O primeiro envolveu a introdução de um nova espécie de coco com o objetivo de estudar a disseminação do uso desse fruto no grupo e os mecanismos de transmissão social envolvidos. Essa disseminação, bastante rápida, em alguns casos deveu-se à aprendizagem inteiramente individual, mas também houve casos de consumo somente após observação de outros indivíduos quebrando cocos ou contato com restos dos cocos. Neste último caso, as eventuais influências sociais estariam restritas ao Realce de Estímulo, mas, onde houve observação direta do comportamento, Emulação ou Imitação não podem ser descartadas. Não foi detectado um padrão definido de preferências na escolha dos indivíduos alvos de observação por coespecíficos em função das características mensuradas dos animais observados. O segundo experimento examinou as preferências na escolha de “martelos" de pedra artificialmente produzidos variando de 300g a 1700g, tendo sido encontrada uma preferência pelos dois martelos mais pesados, embora tenha sido observada uma tendência dos juvenis a usar a ferramenta mais próxima, independentemente do peso. O terceiro experimento abordou o transporte das ferramentas, para determinar se este ocorria quando os “martelos" potenciais se encontravam a 5m ou 10m do seu local de uso (“bigorna"). Os resultados confirmam a ocorrência desse comportamento, o qual, no entanto, foi quase sempre acompanhado do transporte concomitante de cocos. / Three experiments were conducted about tool use to nutcracking by capuchin monkey (Cebus apella) at semi-free ranging condition in Tiete Ecological Park. The first involved the introduction of a new species of nut; the aim was to study the dissemination of the use of this new fruit in the group and the involved social transmission mechanism. The quite fast dissemination occurred by individual learning in some cases, but there were instances of consumption only after observation of other monkeys cracking the new nuts or contact with their leftovers.In the latter case, the possible social influences would be restricted to Stimulus Enhacement, but, in the cases where direct behavioral observation took place, Imitation and Emulation cannot be ruled out. There was no correlation between the choice of targets for observation and the measured traits of the targets. The second experiment examined the preferences in the choice of artificial stone hammers ranging from 300g to 1700g. We found a preference for the two heviest hammers, although the juveniles had a tendency to use the nearest tools, independently of weight. The third experiment was about the transport of tools, to determine if the transport of potential tools occurred when these were found at 5m or 10m from the use site (the “anvil"). The results confirms the occurrence of this behavior, always involving the simultaneous transport of nuts.

O presente estudo teve como objetivo investigar a influência de diferentes sistemas de manejo sobre a reatividade, parâmetros produtivos e de qualidade de carne e carcaça de bovinos confinados. Para isso, foram utilizados 50 novilhos Nelore, alocados em confinamento sob dois sistemas diferentes quanto ao manejo, o tradicionalmente empregado em fazendas (MT) e o baseado em princípios racionais de trabalho e na biologia dos bovinos, conhecido popularmente como manejo racional ou gentil (MR). Os animais de ambos os tratamentos receberam a mesma dieta e ficaram em confinamento por 126 dias (± 18 dias). Foram colhidas, durante os manejos de pesagem em brete, informações quanto ao ganho diário de peso (GDP) e reatividade (através do Escore de Comportamento Composto - ECC). Calculou-se, ao fim do confinamento, o ganho diário médio de peso (GDPtot). Durante o abate, foram colhidas informações quanto à reatividade dos bovinos no bloco de atordoamento (ECCabt). Durante a desossa, foram registradas informações quanto a coloração (L*, a* e b*) das amostras de Longissimus dorsi colhidas, três de cada animal, uma para cada tempo de maturação (0, 7 e 14 dias). Apos o período de maturação, procedeu-se com as análises de perdas de água por exsudação (PAE) e por cozimento (PAC), bem como de força de cisalhamento (MAC). Os resultados indicam que ocorreram influencias dos sistemas de manejo nas características PAE e MAC, com valores superiores e inferiores, respectivamente, em MR. Ocorreram influencias na interação tratamento e manejos ocorridos no GDP, com resultados superiores em MT. No parâmetro MAC ocorreu diferença significativa em relação aos dias de maturação, com diminuição ao longo do tempo de maturação, alem de diferenças nos tratamentos na carne nao maturada, com valores inferiores para MR. As características Contusões (totais, no dianteiro, na ponta de agulha e no traseiro), ECCabt, de coloração (L*, a* e b*) e de PAC não apresentaram diferenças significativas entre os tratamentos ou suas interações. Constatou-se melhor qualidade de carne de animais MR, porém com ganhos de peso ligeiramente inferiores aos do MT. A reatividade apresentou tendência de diminuição ao longo do confinamento, com valores ligeiramente inferiores para animais MR nos manejos de pesagem em brete e mais acentuados no momento do abate. / The present study investigated the influence of different handling systems on the reactivity, production parameters and quality of meat and carcass of confined cattle. The experiment used 50 Nellore steers placed in feedlots that received two different handling systems: the traditionally used in the Brazilian farms (MT) and the based on rational principles of work and in the biology of cattle, known as gentle handling (MR).Both treatments received the same diet and remained in confinement for 126 days (± 18 days). Were taken over the handling in squeeze chute, information about the daily weight gain (GDP) and reactivity (through the Composite Behaviour Score - ECC). At the end of the confinement, the average daily weight gain (GDPtot) was calculated. During the slaughter, was collected information of the reactivity of cattle in stunning pen (ECCabt). During the boning, were recorded information about the color (L *, a * b *) of Longissimus dorsi samples. Three samples from each animal was collected, one for each maturation period (0, 7 and 14 days). After the maturation period, that was preceded with the analysis of water loses by exudation (PAE) and by cooking (PAC) and the shear-force (MAC). The results indicate that there were influences of the handling systems features in PAC and MAC, with values higher and lower, respectively, in MR. Occurred influences in treatment and management occurred in GDP, with superior results in MT. In the MAC, parameter was significant difference for days to maturity, with a reduction over maturation time, and differences in treatment in the meat does not mature, with lower values for MR. The characteristics contusions, ECCabt, meat color (L *, a * b *) and PAC showed no significant differences between treatments or their interactions. It was better quality of meat from animals MR, but with gains weight slightly lower than that of MT. The reactivity, although not significantly different, tended to decrease during the confinement, with slightly lower values for MR in the management of animals weighing more pronounced in squeeze chute and at slaughter.

A memória é considerada por muitos pesquisadores como um dos produtos mais fascinantes da evolução biológica, justamente por proporcionar aos animais a vantagem adaptativa de se utilizar de uma experiência prévia para a solução de problemas necessários para a sobrevivência. Os animais se utilizam de processos mnemônicos durante o forrageamento, a seleção de parceiros sexuais, seleção de habitat e a preferência alimentar. As aranhas são um modelo interessante em estudos de memória e há evidências do uso de experiências passadas na otimização do forrageio: a teia permite que as aranhas capturem e armazenem mais de um item alimentar. Há carência na literatura de estudos comparativos evolutivos da memória, o que dificulta identificar as possíveis pressões seletivas. O primeiro objetivo deste trabalho foi fazer um estudo comparativo de aspectos da memória predatória em aranhas do grupo Orbiculariae. Este grupo é monofilético e tem como principal sinapomorfia a construção de teia orbicular. Porém, ao longo da evolução, o padrão de teia foi se modificando desde uma estrutura plana até uma tridimensional. Tais modificações podem ter gerado diferenças comportamentais e no sistema de memória dessas aranhas. Por este motivo, o outro objetivo, foi traçar a evolução da memória dentro do grupo. Delinearam-se três grupos de estudo com sete espécies. Na condição natural, observou-se a captura de duas presas sucessivas. Na condição experimental I, ofereceu-se uma primeira presa (p1) à aranha e, em seguida, ofereceu-se uma segunda (p2); durante o deslocamento da aranha até p2, retirou-se p1 da teia. Na condição II, ao invés de se oferecer p2, a aranha foi atraída à periferia (simulando a queda de p2). No deslocamento da aranha até a fonte de vibração removeu-se p1. O indício de memória é observado quando, na supressão da presa, a aranha executa um comportamento denominado Busca. Neste, a aranha executa sacudidas/detecções dos fios no centro/refúgio da teia. A busca por p1 roubada foi observada em todas as espécies estudadas, exceto em Z. geniculata no grupo I. A presença de p2 parece interferir na expressão da memória de p1; deixar p2 na teia enquanto busca por p1, aumenta as chances de p2 também ser roubada por ação dos cleptoparasitas. Zosis apresenta algumas peculiaridades, entre elas a ausência de veneno. Dessa forma, o tempo gasto durante a imobilização de p2 parece ser suficiente para causar o esquecimento de p1. Todas as espécies buscaram por p1 quando não houve oferta de p2, inclusive Zosis. O tempo de busca, na condição I, diminui da base de Araneoidea até as famílias mais derivadas. No grupo II, há uma aparente inversão do sinal filogenético e o tempo de busca aumenta na família mais derivada. A estrutura da teia tridimensional parece ser mais complexa e, por este motivo, exigiria um sistema de navegação espacial também mais complexo quando comparado às aranhas orbitelas. A construção da teia parece ter sido crucial para a captura e armazenamento de presas excedentes, e tal comportamento, juntamente com a diversificação das teias, favoreceu a variação e evolução da memória na Ordem Araneae / Memory is one of the most fascinating products of biological evolution, because it endows animals with the adaptive use a prior experiences to solve survival problems. Animals use mnemonic processes during foraging, selection of sexual partners, habitat selection, and feeding preference. Spiders are an interesting model for studies of memory, and there is evidence of their using of past experiences in optimizing foraging: the web allows the spiders to capture and store more than one food item. In literature, there are few comparative studies, and no one about the evolution of memory, making it difficult to identify the possible selective pressures on memory. The first objective here was to make a comparative study on the aspects of predatory memory in spiders of the group Orbiculariae. This group is monophyletic and its main synapomorphy is building an orbicular web. However, during evolution, the web pattern changed from a flat to a three-dimensional structure. Such changes may have caused differences in behavior and memory. For that reason, another goal was to trace the evolution of memory within the group. We used three experimental groups with seven species each. In natural conditions, there was an observation of the capture of two successive preys. In the experimental condition I, a first prey (p1) was offered to the spider and, subsequently, another prey (p2) was offered; during the locomotion of the spider towards p2, p1 was removed from the web. In condition II, instead of offering p2, the spider was attracted to the periphery (simulating the fall of p2). As the spider moved towards the source of vibration, p1 was removed. The evidence of memory is observed when, in the suppression of the prey, the spider performs a behavior called search behavior: the spider runs plucking on threads in the web hub/retreat. The search for stolen p1 was observed in all species studied, except for Zosis geniculata in group I. The presence of p2 appears to interfere with the expression of p1 memory, and also leaving p2 on the web while searching for p1, increases the chances of having p2 stolen by the action of kleptoparasites. Zosis presents some peculiarities, including the absence of poison glands, leading to a prolonged immobilization of p2, in a time lag that could then be sufficient forget p1. All species sought by p1 when there was no offer of p2, including Zosis. The search time, in condition I, decreases from the base of Araneoidea until the most derived families. In group II, there is an apparent reversal of the phylogenetic signal and the search time increases in the most derived family. The three-dimensional structure of the derived webs seems to be more complex and, therefore, it would require a spatial navigation system also more complex if compared to the flat orbweb. The construction of the web seems to have been crucial for prey capture and storage of surpluses, and such behavior, along with the diversification of the webs, favored the variation and evolution of memory in the Order Araneae

A aloamamentação parece desafiar o princípio geral de que o cuidado materno deve restringir-se à própria prole. Embora a aloamamentação em cobaias domésticas Cavia porcellus - espécie em que um macho dominante pode reproduzir-se com várias fêmeas em um sistema de harém e em que os filhotes são precoces e capazes de ingerir alimentos sólidos logo depois do nascimento - já tenha sido observada, não foi submetida até o momento a um estudo sistemático. Na presente pesquisa, realizada com cobaias comuns (Etapa 1) e cobaias albinas (Etapa 2), buscamos descrever os aspectos básicos da interação fêmea-filhote ao longo das primeiras quatro semanas de vida dos filhotes, comparando a freqüência e a duração da amamentação de fêmeas mantidas sozinhas com a sua ninhada (Condição FS, 20 fêmeas) à de fêmeas pareadas quando as ninhadas tinham no máximo 3 dias de diferença (Condição FP, 19 pares de fêmeas), uma condição em que pode surgir aloamamentação. Verificou-se que, apesar da existência de apego em relação à mãe (os filhotes na condição FP permaneciam próximos à mãe e mamaram mais dela do que da fêmea alheia), aproximadamente 60 % dos filhotes alomamaram. A aloamamentação, que se concentrou na primeira semana de vida com um decréscimo marcado em seguida e que não era sempre recíproca, decorreu basicamente da iniciativa dos filhotes. Os resultados não apóiam a hipótese funcional da aloamamentação enquanto competição entre os filhotes por um superávit de alimentação, mas indicam que constitui uma estratégia oportunista dos filhotes, propiciada pelas características da organização social das cobaias. / Allosuckling seems to challenge the general principle according to which maternal care should be retricted to offspring. While already reported, allosuckling in domestic guinea pigs Cavia porcellus - a species in which males may breed with several females, in a harem system, and in which pups are precocious and able to ingest solid food shortly after birth - has not been, to now, systematically described. The aim of the present research, performed with common guinea pigs (Phase 1) and albino guinea pigs (Phase 2) was to describe female-pups interactions throughout development, and to compare such interactions in isolated females with their litter (FS condition, 20 females) and in paired females with their litter (FP condition, 19 pairs), a condition in which allosuckling performance is likely to happen. In spite of pups\' attachment to their mothers (in condition FS, pups remained nearer to their mother than to the other lactating female and had longer and more frequent nursing episodes with her), allosuckling was relatively frequent (approximately 60% of pups were allonursed). Allosuckling peak occurred during the first week of life and markedly decreased thereafter, being mainly under the control of pups. Results do not favor a functional explanation of allosuckling as a competitive strategy of pups for a surplus of food, but suggest it is an opportunistic strategy which is made possible by the specific nature of guinea pigs social organization.

O preá Cavia intermedia (Rodentia: Caviidae), uma espécie recém descrita encontrada exclusivamente no Arquipélago Moleques do Sul, em Santa Catarina, está entre os mamíferos mais raros do planeta. Esta espécie se diferencia de outros preás por características genéticas e morfológicas, muitas delas decorrentes de sua adaptação ao ambiente insular. O objetivo desta pesquisa foi obter dados comportamentais, tomados dentro da necessária matriz ecológica, para o conhecimento da organização social, distribuição espacial e uso dos recursos em C. intermedia. Nossa abordagem utilizou dados existentes de C. magna e C. aperea para situar os resultados em um contexto comparativo, ressaltando possíveis efeitos do isolamento em ambiente insular. Realizamos 25 viagens mensais à ilha, entre novembro de 2007 e dezembro de 2009, com cerca de oito dias cada. Utilizamos 49 armadilhas em um programa de captura-recaptura, no qual os animais foram marcados, medidos, pesados e conferidos quanto ao seu estado reprodutivo. A observação comportamental foi realizada em turnos de duas horas (scans a cada um minuto) em três áreas de grande avistamento de preás (Clareira da barraca, Campinho I e Campinho II), em um total de 636,7 h. Dos 132 indivíduos capturados, 118 foram marcados, sendo 71 machos e 47 fêmeas. A população foi composta em sua maior parte por indivíduos adultos, os quais possuem alta longevidade. Há maturação sexual tardia em relação às espécies preás do continente, além de uma redução no tamanho da ninhada (apenas um filhote). Os nascimentos se concentraram nos meses quentes e chuvosos, cessando em meses frios e com pouca chuva, quando os animais sofrem com a escassez de alimentos. O repertório comportamental de C. intermedia é rico e semelhante em sua forma geral ao de C. aperea, com diferenças em poucas categorias. O hábito alimentar se mostrou herbívoro generalista e dependente dos recursos alimentares disponíveis em cada uma das áreas amostradas, nas quais preás diferentes foram observados. As agregações dentro de cada área se mostraram fluídas, inexistindo territórios, mas encontramos algumas associações entre machos e fêmeas mais duradouras, além de uma hierarquia de dominância entre machos e entre fêmeas. O aumento no número de indivíduos capturados ao longo dos meses revelou um aprendizado por parte dos preás e a maior captura de machos em relação a fêmeas sugere que haja estratégias comportamentais diferentes nos dois sexos. Nossos resultados monstraram que C. intermedia possui diversas características comuns a outras espécies de roedores insulares (população com indivíduos mais velhos, alta longevidade, maturação sexual tardia e redução da ninhada, resposta anti-predatória reduzida, inexistência de territórios, aumento na tolerância a coespecíficos e na freqüência de interações), fruto de adaptações ao ambiente insular. Por outro lado, características como repertório comportamental, aspectos fisiológicos da reprodução e hábito alimentar se mostraram conservadas ao longo da evolução, sendo comuns a outras espécies de preás do continente / The Cavia intermedia cavy (Rodentia: Caviidae) a newly described species exclusively found in the Moleques do Sul Archipelago in the state of Santa Catarina, Brazil is one of the rarest mammals on the planet. This species is differentiated from other cavies on the basis of its genetic and morphologic characteristics, several of them resulting from its adaptation to an island environment. The objective of this research was to obtain behavioral data taken from within the required ecological matrix to shed light into the social organization, spatial distribution and resource use of the C. intermedia. Our approach used existing data for C. magna and C. aperea to frame results into a comparative context, highlighting possible effects from being cut off in an island environment. We have done 25 monthly trips to the island, of approximately 8 days each, between November 2007 and December 2009. We have used 49 traps for a capture-recapture program in which the animals where tagged, measured, weighted and checked for reproductive state. The behavioral observation took place in two-hour rounds (with intervals scans of one minute) in three areas of frequent cavy sightings (Clareira da barraca, Campinho I and Campinho II) totaling 636,7 hours. Out of the 132 individuals captured, 118 were tagged: 71 males and 47 females. This population was composed mostly of adults which had a long lifespan. There was a delayed sexual maturity in this population when compared to the mainland cavy species, as well as a reduction in litter size. Births were concentrated during the warm and rainy months and halted during the cold and dry months, when the animals struggled with food scarcity. The behavioral repertoire of C. intermedia is rich and generally similar to C. apereas, differing in only a few categories. Their feeding habits matched those of a generalist herbivore and depended on the food sources available in each one of the surveyed areas. The gatherings within each area proved to be fluid, without territorial definitions, however we have observed a few longer-term male-female pairings, besides a dominance hierarchy among males and females. The increase in number of captured individuals over the months indicates that the population became aware of and used to the capture process. Besides, the increase in number of males captured in relation to females signals at gender-specific behavioral strategies. Our results show that the C. intermedia has several characteristics in common with other species of island rodents due to adaptations to island life: older population, longer lifespan, late sexual maturity and reduced litter size in response to reduced predatory activity, lack of territories, increase tolerance with coespecific and increase in interactions. On the other hand, certain characteristics such as behavioral repertoire, physiological aspects in reproduction and feeding habits remained the same throughout the evolutionary process, being shared with other cavy species from the mainland