PARENT SESSION
Contributed Oral Session 126: Mammal Ecology: Management, Reproduction, and Food Webs
Thursday, August 11, 8:00 AM - 11:30 AM, Meeting Room 524 C, Level 5, Palais des congrès de Montréal
Selection of feeding trees by the Black Howler Monkey at two scales.
Calmé, Sophie*,1, Rivera, Andrómeda1, 1 El Colegio de la Frontera Sur, Chetumal, Quintana Roo, Mexico
ABSTRACT- Information on food selection and feeding habits is critical for species conservation, particularly in the context of forest landscapes heavily transformed by human activities. In this study, we aimed at identifying the factors involved in the selection of trees used for feeding by the black howler monkey at two scales, the tree and the stand. Four study sites were located within the Calakmul region in the Yucatan peninsula, Mexico. A total of 3152 activity bouts were collected from the dry and rainy season, using the scan-sampling method. To evaluate how trees used by monkeys for feeding differed from those they do not use, we established plots of 10 m-radius around the focal trees (where the majority of the monkeys of a given focal troop was feeding). We measured the height and diameter of all trees >10 cm dbh, and identified the species. Additionally, we conducted a vegetation census in similar plots established at random and where no howler monkey had been observed. Feeding trees were significantly taller than other trees by at least 4 m (T-K multiple comparisons, all p<0.05). Similarly, feeding trees reached larger diameters than non-used trees, by 13 cm or more (T-K multiple comparisons, all p<0.05). At the stand level, focal and random plots had similar numbers of trees >10 cm dbh; however, the frequency distribution of tree species was significantly different (D=0.23, p=0.009). Of the most consumed species, B. alicastrum was marginally more abundant in the focal plots (G=3.32, p=0.068), but Ficus sp. and M. zapota were much more abundant in the focal plots (both G>6.8, p<0.009). Talisia olivaeformis was equally abundant in focal and random plots (G=0.06, p=0.79). The species more abundant in the focal plots were also preferred by monkeys. In contrast, T. olivaeformis was equally abundant in focal and random plots, while the species was not preferred. Black howlers selected the trees on which they fed based at least partially on their dimensions. Moreover, areas they selected to spend most of their time contained higher abundances of their preferred feeding tree species. These findings provide a good basis to establish criteria useful in forest management plans compatible with the conservation of black howler monkeys.
Key words: Alouatta pigra, tree selection, feeding ecology