Primate Ecology and Conservation

This research was carried out by my student, Lynda Jung in 2005 and published in PlosOne in 2015, Abstract: Although the brown howler monkey (Alouatta clamitans) is a relatively well-studied Neotropical primate, its behavioral and dietary flexibility at the intra-population level remains poorly documented. This study presents data collected on the behavior and ecology of two closely located groups of brown howlers during the same period at the RPPN Feliciano Miguel Abdala in southeastern Brazil. One group occupied a primary valley habitat, henceforth the Valley Group (VG), and the other group occupied a regenerating hillside habitat, the Hill Group (HG). We hypothesized differences in the behavior and ecological parameters between these sympatric groups due to the predicted harsher conditions on the hillside, compared to the valley. We measured several habitat parameters within the home range of both groups and collected data on the activity budget, diet and day range lengths, from August to November 2005, between dawn and dusk. In total, behavioral data were collected for 26 (318 h) and 28 (308 h) sampling days for VG and HG, respectively. As we predicted, HG spent significantly more time feeding and consumed less fruit and more leaves than VG, consistent with our finding that the hillside habitat was of lower quality. However, HG also spent less time resting and more time traveling than VG, suggesting that the monkeys had to expend more time and energy to obtain high-energy foods, such as fruits and flowers that were more widely spaced in their hill habitat. Our results revealed that different locations in this forest vary in quality and raise the question of how different groups secure their home ranges. Fine-grained comparisons such as this are important to prioritize conservation and management areas within a reserve.

Data for this project was collected from 2002 to 2005 by Italo Mourthe, Marcos Tokuda and Jean Boubli. Tommy Burch analyses the data and used it to write his MSc by research dissertation.

MSc dissertation abstract - The northern muriqui (Brachyteles hypoxanthus) is a critically endangered species of primate endemic to the Brazilian Atlantic Forest. Strier collected data on the behavioural ecology of the Matão group between 1983-84 at the Reserva Particular Patrimônio Natural-Feliciano Miguel Abdala (RPPN-FMA), Minas Gerais, Brazil. Data on the behavioural ecology of the Jaó group were collected at RPPN-FMA between 2003-04. All methodology used for behavioural data collection of the Jaó group followed methods implemented by Strier in her PhD thesis. The Matão’s and Jaó’s behavioural ecology was compared in this thesis. The Jaó group was more than three times the size of the Matão group during the respective study periods. The Jaó group devoted more time to feeding, socialising, and engaging in “other” activities; whereas, the Matão group devoted more time to resting, travelling, and vocalising. The Jaó group devoted more time to feeding on fruits and flowers than the Matão group; whereas, the Matão group devoted more of their time feeding on leaves than the Jaó group. There was intermonthly variation in the Jaó group’s activity budget, feeding time analyses, diurnal activity cycles, and day range travel lengths. The Matão group only exhibited intermonthly variation in their feeding time analyses and diurnal activity cycles. Greater intragroup feeding competition likely contributed to the larger Jaó group devoting more of their time to feeding and less time to resting than the smaller Matão group, and also why they spent more time feeding on food types at less preferable stages of maturity. In smaller groups with less intragroup feeding competition, adult females and adult males are able to spend the same amount of time feeding overall because adult females can spend more of their time feeding on high quality food resources (in the Matão group, adult females spent more time feeding on flowers than the adult males). As group size increases and intragroup feeding competition for preferred food resources increases, adult females have to spend more time feeding overall (in the Jaó group, adult females spent more time feeding overall than the adult males). Perhaps differences in the two group’s home range habitat quality influenced activity budgets, as the smaller Matão group unexpectedly spent more time travelling. Differences in home range habitat quality could also explain why the Jaó group spent more time feeding on more desirable food resources, comparatively, than the Matão group. The influence of demographic differences undoubtedly also contributed to the behavioural differences that were presented here (the RPPN-FMA population grew from ~50 to >200 individuals, and from two to four groups between study periods). For the purposes of this thesis demographics are not of great focus but are discussed. Differences in rainfall, climatic conditions, and resource availability may have also influenced these results. This type of study is important because it provides insights into how different sized groups adapt their behavioural patterns in order to fulfil their energetic needs. Seasonal shifts in resource availability appears to place a greater stress on groups of larger sizes. Smaller groups may be able to maintain their activity budget year round, something larger groups may be unable to do. Implications for conservation include providing more evidence that even by 2003-04 the population at RPPN-FMA was closer to carrying capacity than it was in 1983-84. Habitat expansion, if possible, would be highly beneficial to the long-term health of the population.