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La Pacifica, Costa Rica

Howling monkeys are aptly named, because their calls can often be heard for miles (HEAR A MANTLED HOWLER). Contrary to what's often reported in the literature, howlers feed on a variety of foods, including leaves, fruit, and flowers, and their diets will vary depending on the season and even the microhabitat. Unlike many primates, howlers also spend much of their day sleeping after their meals. Because of their varied diet, they are a great model for relationships between tooth wear and diet.

The Howler Project is a joint effort led by Dr. Ken Glander from Duke University, and Dr. Mark Teaford from Johns Hopkins University. It is based at a site known as La Pacifica - a cattle ranch that has now been largely converted to rice and fish farming. Fortunately, the patches of forest that support the howlers have remained in place. As the site is in the heart of Costa Rica's Guanacaste region, it has marked wet and dry seasons. With NSF support for a new project led by Dr. Susan Williams from Ohio University and Dr. Chris Vinyard from NEOUCOM, research teams will be working down there twice a year, in the dry season in February, and the wet season in July.

All researchers are housed in cabins at or near the site. Students collect behavioral data on the monkeys and assist in capturing, tagging and releasing the howlers after dental impressions, biological samples, and body measurements have been taken. La Pacifica has proven to be a wonderful first step in the field training of many primatologists (essentially, if you can't hack the "rigors" of fieldwork at La Pacifica, you'd better try another discipline!). The relatively low forest canopy and thin underbrush allow individual howlers, or groups of howlers, to be observed and followed. As most animals are already tagged (with adult females wearing collars and adult males wearing anklets), specific individuals can be captured and released to monitor any number of biological factors.
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