The behavioural ecology of the northern muriqui (Brachyteles hypoxanthus) at the Reserva Particular Patrimônio Natural-Feliciano Miguel Abdala (RPPN-FMA), Minas Gerais, Brazil

Burch, TC

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.

Citation

Burch, T. The behavioural ecology of the northern muriqui (Brachyteles hypoxanthus) at the Reserva Particular Patrimônio Natural-Feliciano Miguel Abdala (RPPN-FMA), Minas Gerais, Brazil. (Dissertation). University of Salford

• Thesis Type: Dissertation
• Deposit Date: Oct 7, 2020
• Publicly Available Date: Oct 7, 2020
• Award Date: Sep 20, 2020