Travel and Spatial Patterns Change When Chiropotes satanas chiropotes Inhabit Forest Fragments

Abstract

Previous studies have used home range size to predict a species' vulnerability to forest fragmentation. Northern bearded saki monkeys (Chiropotes satanas chiropotes) are medium-bodied frugivores with large home ranges, but sometimes they reside in forest fragments that are smaller than the species' characteristic home range size. Here we examine how travel and spatial patterns differ among groups living in forest fragments of 3 size classes (1 ha, 10 ha, and 100 ha) versus continuous forest. We collected data in 6 research cycles from JulyAugust 2003 and January 2005-June 2006 at the Biological Dynamics of Forest Fragments Project (BDFFP), north of Manaus, Brazil. For each cycle, we followed the monkeys at each study site from dawn until dusk for 3 consecutive days, and recorded their location. Although bearded saki monkeys living in 10-ha and 1-ha fragments had smaller day ranges and traveled shorter daily distances, they traveled greater distances than expected based on the size of the forest fragment. Monkeys in the small fragments revisited a greater percentage of feeding trees each day, traveled in more circular patterns, and used the fragments in a more uniform pattern than monkeys in the continuous forest. Our results suggest that monkeys in the small fragments maximize their use of the forest, and that the preservation of large tracts of forest is essential for species conservation. Species with large home ranges sometimes inhabit forest fragments, but doing so can alter behavior, demographics, and ecology, and the monkeys may be vulnerable to stochastic events.

Influence of climatic variables, forest type, and condition on activity patterns of geoffroyi's spider monkeys throughout Mesoamerica

“…Specifically, monkeys spent more time feeding and less time resting in forest fragments than in continuous forest, and hence the feeding effort [sensu Cavigelli, 1999] of monkeys was higher in fragments. Similar differences in activity patterns have been reported for Chiropotes satanas in Brazil [Boyle & Smith, 2010;Boyle et al, 2009] and Alouatta palliata in Mexico [Dunn et al, 2009]. Dunn et al [2009] relate the variations in activity patterns (and feeding effort) to the differences in diet between groups: leaf consumption is higher in the group inhabiting the smallest fragment, and this group visits more food sources resulting in more traveling, more feeding, and less resting.…”

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

“…The tall secondary-growth forest provided travel corridors for the bearded saki monkeys. These monkeys used the corridors regularly to enter and leave the 100-ha fragments; however, the remaining seven forest fragments were isolated, and bearded saki monkeys did not travel into or out of any of the isolated forest fragments during our study (Boyle et al 2009). We present data on bearded saki groups from each of the forest fragments, including the nonisolated fragments, because no other study has been conducted on the behavior of bearded sakis in these forest fragments.…”

“…We arcsin square root transformed all proportional data. We computed densities (individual/ha) based on the home range size for each group (Boyle et al 2009). In the 100-ha fragments, we calculated density of the animals despite the fact that these monkeys left and reentered the fragments, because data were not available on their ranges outside the fragments.…”

“…Forest size was log 10 transformed to meet normality assumptions. Due to the immense size of the continuous forest, we used the home range size of 559 ha in the continuous forest at study site Km41 (Boyle et al 2009) as a measurement continuous forest site. Obviously, 559 ha is smaller than the size of the continuous forest, but it more realistically reflects the area of forest used by the monkeys.…”

“…obtains approximately 88% of its diet from fruit, a majority of which is seed material (Ayres 1981;van Roosmalen et al 1981;Kinzey and Norconk 1990). In continuous forest, bearded sakis travel long daily distances (van Roosmalen et al 1981;Norconk et al 2003;Boyle et al 2009), occupy large home ranges of 200-559 ha (Ayres 1981;van Roosmalen et al 1981;Boyle et al 2009), and live in large groups consisting of an average of 21.8 individuals (van Roosmalen et al 1981;Kinzey and Norconk 1990;Norconk et al 2003). These large groups divide into smaller subgroups and then reassemble into large groups multiple times throughout the day (van Roosmalen et al 1988;Norconk 2007).…”