Dados do Trabalho

Título

HABITAT AREA AND FRUIT AVAILABILITY AND CONSUMPTION INFLUENCE THE RANGING BEHAVIOR OF ALOUATTA GUARIBA CLAMITANS IN SOUTHERN BRAZIL

Resumo

Understanding primate ranging behavior and its main ecological drivers can improve the effectiveness of management and conservation strategies in human-modified landscapes. We investigated the influence of forest fragment size on the home range of brown howler monkeys (Alouatta guariba clamitans) and the main ecological drivers of their daily path length (DPL). We recorded GPS locations of three free-ranging groups inhabiting small forest fragments (<10 ha) and three groups inhabiting large fragments (>90 ha) during 32 months. We estimated home range size via the Local Convex Hulls method, an advanced non-parametric kernel model, and the DPL by adding up straight-line distances measured between consecutive GPS locations scored during daily group follows. We also recorded data on food availability, diet composition, group size, and ambient temperature throughout the study. Home ranges varied from 2.2 to 11.3 ha with core areas of 1.3 to 3.6 ha. Mean (± SD) DPL ranged from 387 (± 104) to 1171 (± 778) m. Home ranges in large fragments (mean ± SD, 9 ± 2 ha) were about twice the size of those in small fragments (4 ± 2 ha), but their core areas were similar (3 ± 1 vs 2 ± 1). DPL tended to increase with increasing group size (R2= 0.11, P = 0.1) and was longer in large fragments. We found in a multi-model analysis that DPL was positively influenced by food, particularly ripe fruit, availability and consumption, maximum ambient temperature, and daylength. In sum, we showed the combined effects of habitat size, food availability, diet, and some climatic factors on the ranging behavior of the behaviorally flexible brown howlers. We highlight that severe natural and/or anthropogenic stressors that influence habitat patch size and resource availability can reduce home range and DPL and potentially constrain the long-term viability of isolated groups.

Financiamento

Brazilian Higher Education Authority/CAPES (PNPD grant # 2755/2010) and Brazilian National Research Council/CNPq for a research fellowship (PQ # 303154/2009-8 and 303306/2013-0).

Palavras-chave

Forest fragmentation; arboreal mammals; space use