Sleeping site selection of Francois’s langur (Trachypithecus francoisi) in two habitats in Mayanghe National Nature Reserve, Guizhou, China

Abstract

Sleeping site selection is an important aspect of the behavioral biology of primates. Comparison of different habitats for the same species in this context enhances understanding of their adaptation to altered environments. We collected data on sleep-related behaviors for 6 groups of Francois's langur (Trachypithecus francoisi) in two habitats, in Mayanghe National Nature Reserve, Guizhou, China. Regardless of habitat, all sleeping sites were located in areas of steep terrain of ≥60°. In undisturbed habitat, sleeping sites were located only in evergreen broadleaf forest with rock caves and crevices surrounded mainly by a vegetation layer of shrub + rock. In disturbed habitat, sleeping sites were also located in mixed evergreen and deciduous broadleaf forest and in grassland, including rock caves, crevices, and pits, surrounded mainly by arbor + shrub and shrub + rock. Wild food availability was higher in undisturbed habitat than disturbed habitat, but food abundance around sleeping sites was lower. Water sources included river and seasonal gully or pond. There was strong positive correlation between use of sleeping sites away from the river valley and occurrence of seasonal water sources. The number of sleeping sites varied across groups, numbering 6, 7, and 10 for three specific groups. Few sleeping sites were used all year round. Six consecutive nights was the longest recorded run. Francois's langurs' sleeping habits differed between two habitats. In undisturbed habitat, minimizing predation risk appeared to predominate, expressed by choosing steep terrain, open visual field, and inconspicuous presleeping behavior. In disturbed habitat, along with predation avoidance, food resources may strongly influence sleeping site selection, as demonstrated by the richer food abundance and greater foraging activity around the site. Finally, water resources may influence choice of sites distant from the river; such sites were used less frequently during water shortages.

Trachypithecus delacouri (Primates: Cercopithecidae)

“…They may use from 3 to 5 caves in their home range, typically arriving at the caves after dark and leaving before sunrise (Nadler 1996). However, unlike T. francoisi (Zhou and Huang 2010), T. delacouri does not seem to actively seek crevices or caves, but to use them if available close to their feeding sites; otherwise, they sleep on exposed rock surfaces at all elevations (Wang et al 2011;Workman 2010b). …”

Factors Influencing the Ranging Behavior of Chacma Baboons (Papio hamadryas ursinus) Living in a Human-Modified Habitat

“…Any study of the effects of alien species eradication will also need to account for the variety of other ecological factors that influence primate ranging behavior, including food resources (Buzzard 2006;Clutton-Brock 1975;Di Fiore 2003); sleeping sites (Smith et al 2007;Wang et al 2011;Zhou et al 2011); geophagy sites (Pages et al 2005;Shimooka 2005;Spehar et al 2010); environmental conditions such as day length, temperature, and rainfall (Dunbar 1992;Hill et al 2003;van Doorn et al 2010); predators (Altmann and Altmann 1970;Isbell 1994;Matsuda et al 2009); and observer presence (Crofoot et al 2010;Rasmussen 1991).…”

Use of sleeping sites by a titi group (Callicebus coimbrai) in the Brazilian Atlantic Forest

“…Repeated use of sleeping sites, apparently in response to relatively harsh winter or dry season conditions, has been recorded for a number of catarrhines (Raemaekers and Chivers 1980;Zhao 1999;Liu and Zhao 2004;Wang et al 2011). In our study, in contrast, sleeping sites were most often repeated during the wet season months of June, July, and August, when preferred resources such as fruit were apparently most abundant (Souza-Alves 2010), although the small number of sites used overall meant that the same ones were used frequently in all months.…”