The behaviour and activity budgets of two sympatric sloths; Bradypus variegatus and Choloepus hoffmanni.

It is usually beneficial for species to restrict activity to a particular phase of the 24-hour cycle as this enables the development of morphological and behavioural adaptations to enhance survival under specific biotic and abiotic conditions. Sloth activity patterns are thought to be strongly related to the environmental conditions due to the metabolic consequences of having a low and highly variable core body temperature. Understanding the drivers of sloth activity and their ability to withstand environmental fluctuations is of growing importance for the development of effective conservation measures, particularly when we consider the vulnerability of tropical ecosystems to climate change and the escalating impacts of anthropogenic activities in South and Central America. Unfortunately, the cryptic nature of sloths makes long term observational research difficult and so there is very little existing literature examining the behavioural ecology of wild sloths. Here, we used micro data loggers to continuously record, for the first time, the behaviour of both Bradypus and Choloepus sloths over periods of days to weeks. We investigate how fluctuations in the environmental conditions affect the activity of sloths inhabiting a lowland rainforest on the Caribbean coast of Costa Rica and examined how this might relate to their low power lifestyle. Both Bradypus and Choloepus sloths were found to be cathemeral in their activity, with high levels of between-individual and within-individual variation in the amounts of time spent active, and in the temporal distribution of activity over the 24-hour cycle. Daily temperature did not affect activity, although Bradypus sloths were found to show increased nocturnal activity on colder nights, and on nights following colder days. Our results demonstrate a distinct lack of synchronicity within the same population, and we suggest that this pattern provides sloths with the flexibility to exploit favourable environmental conditions whilst reducing the threat of predation.

Time allocations for different activities in the fiddler crab Tubuca rosea(Tweedie, 1937) (Brachyura, Ocypodidae)ˆien

Investigating the time activity budgets of fiddler crabs is very important to determine the effects of sex and body size on allocating time for different activities. Few previous studies investigated the effects of sex and body size on time allocations in underground mating species. This study determines the effects of sex, size and their interaction on time allocations in a surface mating species (Tubuca rosea (Tweedie, 1937)). The surface activities of large and small, male and female crabs were video recorded. Afterwards time allocations for various activities (e.g., feeding, standing (vigilance), walking, inside burrows, grooming, burrowing, mating, and for males only, fighting and claw-waving) were calculated. All crabs spent most of their time on feeding than on other activities. Smaller crabs spent more time being vigilant, whereas larger crabs spent more time on courtship displays (grooming, and waving), and fighting. Between sexes, females spent more time standing, but less time on walking and grooming than males. Predation risk, reproductive maturation, breeding/non-breeding season, and energy conservation could be important factors for shaping time allocations in T. rosea.

Time allocations for different activities in the fiddler crab Tubuca rosea(Tweedie, 1937) (Brachyura, Ocypodidae)ˆien

Investigating the time activity budgets of fiddler crabs is very important to determine the effects of sex and body size on allocating time for different activities. Few previous studies investigated the effects of sex and body size on time allocations in underground mating species. This study determines the effects of sex, size and their interaction on time allocations in a surface mating species (Tubuca rosea (Tweedie, 1937)). The surface activities of large and small, male and female crabs were video recorded. Afterwards time allocations for various activities (e.g., feeding, standing (vigilance), walking, inside burrows, grooming, burrowing, mating, and for males only, fighting and claw-waving) were calculated. All crabs spent most of their time on feeding than on other activities. Smaller crabs spent more time being vigilant, whereas larger crabs spent more time on courtship displays (grooming, and waving), and fighting. Between sexes, females spent more time standing, but less time on walking and grooming than males. Predation risk, reproductive maturation, breeding/non-breeding season, and energy conservation could be important factors for shaping time allocations in T. rosea.(AU)

Behavioral flexibility of a group of bearded capuchin monkeys (Cebus libidinosus) in the National Park of Brasília (Brazil): consequences of cohabitation with visitors / Flexibilidade comportamental de um grupo de macacos-prego (Cebus libidinosus) no Parque Nacional de Brasília (Brasil): conseqüências da convivência com os visitantes

Increasing urbanization and deforestation have enhanced the opportunities of contact between humans and monkeys and the impact of human activities on primate behavior is receiving growing attention. This study explores whether activity budgets and diet of a group of capuchin monkeys (Cebus libidinosus) inhabiting the area of the swimming pools of the National Park of Brasília is affected by the presence of visitors providing food to them. During one year, both in the dry and the wet seasons, we scored capuchins' behavior via scan sampling every ten minutes. Results showed that this group spent less time foraging for wild foods than other comparable groups living in similar habitats. Moreover, capuchins relied more on human food during the dry season, when pulpy fruits were less available, than in the wet season. Our findings confirm other studies on different monkey species that have shown that access to human food decreases the time spent foraging for wild food and the home range size. They also show that capuchins are able to modify their diet, to exploit alternative food sources, and to change their activity budget in response to the availability of new food opportunities and to seasonal food availability.

Recentemente, o impacto de atividades humanas sobre o comportamento de primatas tem recebido maior importância dado o crescente desmatamento e urbanização, que têm favorecido o aumento do contato entre humanos e macacos. O presente estudo descreve os padrões de atividade e a dieta de um grupo de macacos-prego (Cebus libidinosus) que vive no Parque Nacional de Brasília. O Parque é freqüentado diariamente por visitantes, de modo que os animais estão habituados à presença humana, bem como ao consumo de itens de sua dieta. Observações comportamentais do grupo foram realizadas ao longo de um ano, compreendendo a estação seca e a chuvosa, utilizando-se registro de varredura a cada 10 minutos. Resultados obtidos indicaram que o grupo despendeu menos tempo forrageando itens naturais do que outros grupos vivendo em habitats similares. Além disso, durante a estação seca, quando há menor disponibilidade dos frutos de polpa, os macacos-prego alimentaram-se mais de itens da dieta humana como uma fonte alternativa de recurso. Como demonstrado em estudos anteriores realizados com outras espécies de macacos, a alimentação baseada em itens da dieta humana pareceu diminuir a motivação dos animais para forragear no seu habitat natural, assim como promoveu a redução do tempo gasto no forrageamento e a redução de sua área de uso. Nossos resultados indicaram ainda que o consumo de comida humana reflete o caráter adaptável dos animais em explorar fontes alternativas de recurso, bem como a sua habilidade em modificar a sua dieta e padrões de comportamento face às mudanças ambientais.

Behavioral flexibility of a group of bearded capuchin monkeys (Cebus libidinosus) in the National Park of Brasília (Brazil): consequences of cohabitation with visitors

Increasing urbanization and deforestation have enhanced the opportunities of contact between humans and monkeys and the impact of human activities on primate behavior is receiving growing attention. This study explores whether activity budgets and diet of a group of capuchin monkeys (Cebus libidinosus) inhabiting the area of the swimming pools of the National Park of Brasília is affected by the presence of visitors providing food to them. During one year, both in the dry and the wet seasons, we scored capuchins' behavior via scan sampling every ten minutes. Results showed that this group spent less time foraging for wild foods than other comparable groups living in similar habitats. Moreover, capuchins relied more on human food during the dry season, when pulpy fruits were less available, than in the wet season. Our findings confirm other studies on different monkey species that have shown that access to human food decreases the time spent foraging for wild food and the home range size. They also show that capuchins are able to modify their diet, to exploit alternative food sources, and to change their activity budget in response to the availability of new food opportunities and to seasonal food availability.

Recentemente, o impacto de atividades humanas sobre o comportamento de primatas tem recebido maior importância dado o crescente desmatamento e urbanização, que têm favorecido o aumento do contato entre humanos e macacos. O presente estudo descreve os padrões de atividade e a dieta de um grupo de macacos-prego (Cebus libidinosus) que vive no Parque Nacional de Brasília. O Parque é freqüentado diariamente por visitantes, de modo que os animais estão habituados à presença humana, bem como ao consumo de itens de sua dieta. Observações comportamentais do grupo foram realizadas ao longo de um ano, compreendendo a estação seca e a chuvosa, utilizando-se registro de varredura a cada 10 minutos. Resultados obtidos indicaram que o grupo despendeu menos tempo forrageando itens naturais do que outros grupos vivendo em habitats similares. Além disso, durante a estação seca, quando há menor disponibilidade dos frutos de polpa, os macacos-prego alimentaram-se mais de itens da dieta humana como uma fonte alternativa de recurso. Como demonstrado em estudos anteriores realizados com outras espécies de macacos, a alimentação baseada em itens da dieta humana pareceu diminuir a motivação dos animais para forragear no seu habitat natural, assim como promoveu a redução do tempo gasto no forrageamento e a redução de sua área de uso. Nossos resultados indicaram ainda que o consumo de comida humana reflete o caráter adaptável dos animais em explorar fontes alternativas de recurso, bem como a sua habilidade em modificar a sua dieta e padrões de comportamento face às mudanças ambientais.

Time-activity budgets and behaviour of the Amazilia hummingbird, Amazilia amazilia (Apodiformes: Trochilidae) in an urban environment

This study deals with the time-activity budgets of Amazilia amazilia, a territorial hummingbird, and its preferences for different flower species and perches in the gardens of Lima (Peru) in September 2001. A. amazilia spent an important part of its time resting on perches (ca. 80%) and only 15.5% for foraging, devoted essentially to flower visitation and only 0.3% for hunting and drinking water. Territorial defence accounted for 2% of total time, mostly against Coereba flaveola, an introduced nectarivorous species that seem to be an important competitor of A. amazilia. Flower use is not directly related to flower abundance (chi(2)9, = 1,546, p<0.0001), with Justicia brandegeana and red-flowered Salvia splendens being selected and Impatiens balsamina being rejected. The large amount of time spent on the perches makes them an important element of the habitat. The perches selected are typically on trees, close to the flowers visited, and in a low vertical and middle horizontal position, surrounded by low foliage density, probably to minimize heat loss.

Se estudi¨® la distribuci¨®n del tiempo en las actividades de Amazilia amazilia, un colibr¨ª territorial, y sus preferencias por diferentes flores y perchas en los jardines de Lima (Per¨²), en septiembre de 2001. A. amazilia pasa una parte importante de su tiempo descansando en las perchas (ca. 80%) y s¨®lo un 15.5% aliment¨¢ndose, dedicado fundamentalmente a visitar flores y s¨®lo un 0.3% a cazar y a beber agua. La defensa del territorio ocup¨® un 2% del tiempo total, la mayor parte frente a Coereba flaveola, una especie nectar¨ªvora introducida que parece constituir un importante competidor de A. amazilia. El uso de las distintas especies de flores no se relaciona con su abundancia (¦Ö29 = 1546, p<0.0001), siendo Justicia brandegeana y Salvia splendens de flores rojas seleccionadas e Impatiens balsamina rechazada. La gran cantidad de tiempo que pasa en las perchas las convierte en un elemento importante del h¨¢bitat. Las perchas seleccionadas se encuentran t¨ªpicamente en ¨¢rboles, cercanas a las flores que visita y, se sit¨²an en posici¨®n baja y central rodeadas de baja densidad de follaje, probablemente para minimizar la p¨¦rdida de calor.