Long‐term patterns of sleeping site use in wild saddleback (Saguinus fuscicollis) and mustached tamarins (S. mystax): Effects of foraging, thermoregulation, predation, and resource defense constraints

Abstract

Sleeping sites are an important aspect of an animal's ecology given the length of time that they spend in them. The sleep ecology of wild saddleback and mustached tamarins is examined using a long‐term data set covering three mixed‐species troops and 1,300+ tamarin nights. Seasonal changes in photoperiod accounted for a significant amount of variation in sleeping site entry and exit times. Time of exit was more closely correlated with sunrise than time of entry was with sunset. Both species entered their sleeping sites when light levels were significantly higher than when they left them in the morning. Troops of both species used >80 individual sites, the majority being used once. Mustached tamarins never used the same site for more than two consecutive nights, but saddlebacks reused the same site for up to four consecutive nights. Mustached tamarins slept at significantly greater heights than saddleback tamarins. There were consistent interspecific differences in the types of sites used. Neither the presence of infants, season, nor rainfall affected the types or heights of sites chosen. Sleeping sites were located in the central area of exclusive use more often than expected, and their position with respect to fruiting trees indicated a strategy closer to that of a multiple central place forager than a central place forager. These findings are discussed in light of species ecology, with particular reference to predation risk, which is indicated as the major factor influencing the pattern of sleeping site use in these species. Am J Phys Anthropol 2007. © 2007 Wiley‐Liss, Inc.

Influences on Gum Feeding in Primates

“…Presentation time may be an important factor in this case as callitrichids are known to enter their sleeping sites from mid afternoon (Smith 2007). Feeding itinerary may not be as important for specialist gummivores with intestinal adaptations; indeed several such species show either a peak of gum feeding at the start of their active period or a bimodal pattern with peaks at the start and end of their active period (e.g.…”

Sleeping site use of the white-headed langur Trachypithecus leucocephalus: The role of predation risk, territorial defense, and proximity to feeding sites

“…To examine the possibility that white-headed langurs display either a CPF strategy, or MCPF strategy, we estimated the linear distances between the last group feeding site and the observed sleeping site, the nearest sleeping site used, and the central place and compared them via paired t-tests. Following Smith et al (2007), the central place in a CPF strategy is expressed as the arithmetic mean of the coordinates of all sleeping sites used. We estimated the linear distances from sleeping site to the last group feeding site of the day and to the first group feeding site of the following morning and used Wilcoxon signed-rank tests to examine the difference.…”

“…A final element thought to influence where primates sleep is proximity to food resources. Some primates prefer to sleep near or in feeding sites, where they can eat either immediately before bed or first thing in the morning upon waking (e.g., Ateles geoffroyi, Chapman et al, 1989;Colobus guereza, von Hippel, 1998; Saguinus fuscicollis and S. mystax, Smith et al, 2007). This can reduce the time and energetic spent searching for food.…”

“…Patterns observed in the use of sleeping sites may reflect strategies to minimize predation risk. Studies document that species under high predation use many different sleeping sites if they are available in order to reduce the possibility of any one location being discovered (Reichard, 1998;Franklin, 2004;Smith et al, 2007). Alternatively, some researchers suggest that reuse of sleeping sites increases the animal's familiarity with a location, thus improve chances for escape (Struhsaker, 1967;Di Bitetti et al, 2000).…”

“…Alternatively, some researchers suggest that reuse of sleeping sites increases the animal's familiarity with a location, thus improve chances for escape (Struhsaker, 1967;Di Bitetti et al, 2000). By retreating to sleeping sites carefully and discreetly (e.g., by showing increased vigilance, making less noise, and moving rapidly without hesitation), prey species can also avoid predator detection (Reichard, 1998;Di Bitetti et al, 2000;Smith et al, 2007). Territory or resource (e.g., foods) defense may also influence sleeping site distribution in the home range (Anderson, 1998).…”