Supplementary Material for: Habitat Quality of the Woolly Spider Monkey <i>(Brachyteles hypoxanthus)</i>

This study examines how habitat structure affects the home range use of a group of <i>Brachyteles hypoxanthus</i> in the Brigadeiro State Park, Brazil. It has been reported that most of the annual feeding time of woolly spider monkeys is spent eating leaves, but they prefer fruits when available. We hypothesise that the protein-to-fibre ratio (PF; best descriptor of habitat quality for folivorous primates) is a better descriptor of habitat quality and abundance for these primates than the structural attributes of forests (basal area is the best descriptor of habitat quality for frugivorous primates of Africa and Asia). We evaluated plant community structure, successional status, and PF of leaf samples from the dominant tree populations, both within the core and from a non-core area of the home range of our study group. Forest structure was a combination of stem density and basal area of dominant tree populations. The core area had larger trees, a higher forest basal area, and higher stem density than the non-core area. Mean PF did not differ significantly between these sites, although PF was influenced by differences in tree regeneration guilds. Large-bodied monkeys could be favoured by later successional stages of forests because larger trees and denser stems prevent the need for a higher expenditure of energy for locomotion as a consequence of vertical travel when the crowns of trees are disconnected in early successional forests. Forest structure variables (such as basal area of trees) driven by succession influence woolly spider monkey abundance in a fashion similar to frugivorous monkeys of Asia and Africa, and could explain marked differences in ranging behaviour and home range use by<i> B. hypoxanthus</i>.本研究探讨了生境结构对巴西布里加代罗州立公园内一群绒毛蜘蛛猴（Brachyteles hypoxanthus）家域利用的影响。已有研究表明，绒毛蜘蛛猴全年多数觅食时间用于取食树叶，但在果实可获取时更偏好取食果实。我们提出研究假设：相较于森林结构属性（胸高断面积是非洲与亚洲食果灵长类生境质量的最佳表征指标），蛋白质与纤维比值（protein-to-fibre ratio，简称PF；食叶灵长类生境质量的最佳表征指标）能更精准地反映这类灵长类的生境质量与种群丰度。我们采集了研究种群家域核心区域与非核心区域内优势树种的叶片样本，以此开展植物群落结构、演替状态以及PF值的测定与评估。森林结构由优势树种的茎干密度与胸高断面积共同表征。相较于非核心区域，核心区域的树木个体更大、森林胸高断面积更高，且茎干密度也更高。尽管PF值受树木更新功能群差异的影响，但两个区域的平均PF值并无显著统计学差异。体型较大的灵长类或更受益于森林的晚期演替阶段：在早期演替森林中，树木树冠彼此分离，垂直移动会导致运动能耗升高，而晚期演替阶段的高大树木与密集茎干可有效降低这类能耗。由森林演替驱动的森林结构变量（如树木胸高断面积），对绒毛蜘蛛猴种群丰度的影响模式与亚洲、非洲的食果灵长类相似，这或可解释B. hypoxanthus在活动行为与家域利用上的显著差异。