Strategies for navigating large areas: a GIS spatial ecology analysis of the bearded saki monkey, Chiropotes sagulatus, in Suriname.

Animals with long day paths and large home ranges expend a considerable amount of energy on travel. Studies have shown that in the interest of reducing energy expenditure, animals selectively navigate the landscape using a variety of strategies. However, these studies have generally focused on terrestrial animals. Here we present data on an exceedingly mobile arboreal animal, bearded saki monkeys, in a topographically variable landscape in Suriname. Using ArcMap and Google Earth, we explore two potential navigation strategies: the nonrandom use of travel areas and the use of ridges in slope navigation. Over a year of data collection, bearded sakis were found to use relatively long travel paths daily, use some areas more intensely than others for travel, and when travel paths were converted to strings of points, 40.3% and 63.9% of the points were located on (50 m from the main ridgeline) or near (100 m from the main ridgeline) ridge tops, respectively. Thus in a habitat of high relief we found support for intensive use of ridge tops or slopes close to ridge tops by bearded sakis. Selective habitat use may be related to surveying tree crowns for fruit by large, fast moving groups of bearded sakis or monitoring the presence of potential predators.