Behavior patterns of Southern Bearded Sakis (Chiropotes satanas) in the fragmented landscape of Eastern Brazilian Amazonia

Abstract

The endangered but poorly studied southern bearded saki, Chiropotes satanas, faces extremes of habitat fragmentation throughout its geographic range in eastern Amazonia. This article focuses on the behavior of the members of two groups--a large one (30-34 members) in continuous forest (home range=69 ha) and a much smaller one (7 members) on a 17-ha man-made island--at the Tucuruí Reservoir on the Tocantins River. Quantitative behavioral data were collected through scan and all-events sampling. Both groups were characterized by the fission-fusion pattern of social organization typical of the genus and relatively high rates of traveling and feeding, also characteristic of the genus. However, the island group spent significantly more time resting and significantly less traveling than the mainland group, presumably as a function of its much smaller home range. Despite resting more, island group members engaged in significantly less social interaction, possibly because of the much smaller size of this group (which also affected visibility), or other factors, such as nutritional stress. Affiliative associations of males were a mainstay of social behavior in both groups and interspecific associations with capuchins (Cebus apella) and squirrel monkeys (Saimiri sciureus) were relatively common, especially in the mainland group. Overall, the island group presented a relatively reduced behavioral repertoire, apparently reflecting factors such as group size and the size and quality of its home range.

Effects of food availability and climate on activity patterns of western black-crested gibbons in an isolated forest fragment in southern Yunnan, China

“…Compared with groups in intact forest, lion-tailed macaques (M. silenus) in a disturbed forest fragment consistently spent more time moving/traveling than resting because of high levels of human presence (Menon and Poirier 1996). The black bearded saki (Chiropotes satanas) in a fragmented landscape of Amazonia, however, spent significantly more time resting and less time traveling than the mainland group (Boyle and Smith 2010;Silva and Ferrari 2009). This trend was also reported in study of the ursine colobus (C. vellerosus, Wong and Sicotte 2007).…”

“…Primates usually increase traveling time in search of fruit since it is distributed more sparsely than other foods (Fan and Jiang 2008;Pavelka and Knopff 2004). However, the smallfragment groups' movements may be constrained as a function of their limited space available and shorter traveling distances, or better habitat quality in small fragments may allow them to move less and rest more (Boyle and Smith 2010;Silva and Ferrari 2009).…”

Social behavior in fission–fusion groups of red uakari monkeys (Cacajao calvus ucayalii)

“…Although male Chiropotes satanas at Tucuruí, Brazil were affiliative, Veiga and Silva [2005] and Silva and Ferrari [2009] did not report the formation of discrete bachelor groups or sequences of aggression between groups of males. Although levels of aggression were not compared statistically, adult male C. calvus ucayalii often have scars and injuries [personal observation] that are presumably caused by fights and levels of aggression in C. calvus ucayalii may prove higher than in Chiropotes.…”

“…have multimale breeding systems in which females are the dispersing sex [see Di Fiore & Campbell, 2007;Stumpf, 2007; for reviews], but the social systems for the Pitheciines are less well known. A few studies have considered the social behavior of Chiropotes [Silva & Ferrari, 2009;Veiga & Silva, 2005;Veiga et al, 2006], but Cacajao has rarely been studied, and most studies have concentrated on the distribution, diet and ranging behavior of the genus [e.g. Aquino, 1988Aquino, , 1998Ayres, 1986Ayres, , 1989Barnett et al, 2005;Boubli, 1997Boubli, , 1999Hershkovitz, 1987].…”

Behavioral modifications in northern bearded saki monkeys (Chiropotes satanas chiropotes) in forest fragments of central Amazonia

“…Most of the research on bearded sakis living in humanaltered habitats has focused on forested islands that resulted from hydroelectric dam construction and flooding (Peetz 2001;Santos 2002;Veiga 2006;Veiga and Ferrari 2006;Silva and Ferrari 2009), and not mainland populations of bearded sakis. The purpose of our study was to determine to what extent the behavior of bearded saki groups inhabiting mainland forest fragments of various sizes differed from bearded saki groups living in continuous forest.…”