Concordância espaço-temporal e intensidade de competição em grupos de baleia jubarte: evidências de uma série temporal de 10 anos

The theory of sexual selection states that individuals more capable of attracting, selecting and competing for partners are more successful on reproduction than the less fit individuals. Competition for sexual partners can be observed in different populations of humpback whales (Megaptera novaeangliae). These large cetaceans migrate seasonally from feeding areas, in high latitudes, to breeding areas, in low latitudes, where they spend the winter. During the breeding season females with and without calves are escorted by transient competitive groups of males. Seeking reproductive success in the same group, various males exhibit aggressive behaviors searching for proximity to the disputed female. Breeding areas are usually located in warm and shallow waters that provide greater security to newborn calves. The Abrolhos Bank, in the Bahia State, is the main breeding area of the species in Brazil. In this study, we used data collected in this region between 2003 and 2012. We tested the hypothesis that there is temporal fluctuation in the abundance of competitive groups and, thus, there is variation in the levels of competition among males during the breeding season. We expected to find higher competition at the beginning of the season since there are a large number of males competing for a small number of females available for mating, because some of them would still be pregnant with calves conceived on the previous year. As the pregnant females give birth to their calves and can again get into heat, the competition among males would be softened, represented by a smaller number of individuals in competitive groups and a larger number of groups sighted. To test this hypothesis we compared the number of individuals per group and number of groups sighted (response variables) between the beginning and the end of the reproductive season (explanatory variable) by using generalized linear models. We used the Living Planet Index (LPI),...

Efeitos da desconexão de habitat na diversidade funcional de anfíbios anuros (Amphibia: Anura) na Mata Atlântica

Amphibian populations worldwide have been suffering declines generated by habitat degradation, loss, fragmentation and habitat split. With habitat loss and fragmentation in the landscape comes habitat split, which is the separation between the adult anuran habitat and breeding sites, forcing individuals to move through matrix during breeding seasons. Thus, habitat split increases the chance of extinction of amphibians with aquatic larval development and acts as a filter in the selection of species having great influence on species richness and community structure. The use of functional diversity allows us to consider the identity and characteristics of each species to understand the effects of fragmentation processes. The objective of this study was to estimate the effects of habitat split, as well as habitat loss in the landscape, on amphibians functional diversity (FD) and species richness (S). We selected 26 landscapes from a database with anuran surveys of Brazilian Atlantic Forest. For each landscape we calculated DF, S and landscape metrics at multiple scales. To calculate the DF we considered traits that influenced species use and persistence in the landscape. We refined maps of forest remnants and water bodies for metrics calculation. To relate DF and S (response variables) to landscape variables (explanatory variables), we used a model selection approach, fitting generalized linear models (GLMS) and making your selection with AICc. We compared the effect of model absence and models with habitat split, habitat amount and habitat connectivity effects, as well as their interaction. The most plausible models for S were the sum and interaction between habitat split in 7.5 km scale. For anurans with terrestrial development, habitat amount was the only plausible explanatory variable, in the 5 km scale. For anurans with aquatic larvae habitat amount in larger scales and the addition of habitat amount and habitat split were plausible...