Efeito da disponibilidade de alimento na distribuição espacial de bugios-ruivos em um fragmento de Mata Atlântica

Abstract

Understanding the ecological factors that influence the presence, abundance, and distribution of species within their habitats is critical for ensuring their long-term conservation. In the case of primary consumers, such as most primates, the richness and availability of plant foods are considered key drivers of population density at different spatial scales. However, little is known about how (and whether) these variables influence the spacing of social units within a finer, habitat patch level scale. I investigated whether resource richness and spatiotemporal food availability are good predictors of local, within-habitat spatial distribution of brown howler monkeys (Alouatta guariba clamitans) in a 1,200 ha Atlantic forest remnant in southern Brazil. I censused the population every two weeks from January to June 2015 by walking 205 km distributed in five line transects. Then, I used data on tree inventories in all sighting and control plots and phenological surveys of 17 top food tree species to estimate bi-weekly food availability for the monkeys. We recorded a total of 95 sightings (2-12 sightings/sampling period) and found that fruit (ripe and unripe) availability was higher in sighting than in control plots. Leaf availability was similar. On the other hand, the number of individuals observed in each sighting was marginally directly related to the availability of ripe fruits, but not to tree richness or the availability of unripe fruits, mature leaves, and young leaves. We concluded that the distribution and availability of fruit sources was an important driver of the pattern of habitat use by brown howler during the study period.