Climate-driven variation in the use of space

Resumo

In tropical and subtropical areas, climatic seasonality affect marsupials space use through changes in food, mate and nest availability in each season. These effects can be enhanced when population size has an additive effect in the most limiting season. In this study, we tested if the daily home range area and the intensity of use of the neotropical marsupial Metachirus nudicaudatus is affected by population size, climatic (dry and wet) and reproductive (breeding and non-breeding) seasons, and differs between sexes. We developed a total of 22 candidate models (11 each) and examined model fit with Akaike's information criterion for small samples. Metachirus nudicaudatus space use was affected by climatic seasonality, with individuals exploring larger areas in the dry season, probably in search for food. Population size had no effect on their spatial arrangement, suggesting intraspecific competition for food as the main population regulatory mechanism. Further studies should test experimentally the effect of food availability on the space use of marsupials in an attempt to confirm or rebut this hypothesis.