Wildsumaco Wildlife Sanctuary is a new reserve located on the eastern slopes of the Andes in Ecuador (400 hectares; 1400 m elevation; S 00° 40.28′ W 77° 35.91′). The reserve consists of primary and secondary forest in a matrix of agricultural land. A top priority for the sanctuary and the affiliated Rio Pucuno Foundation is to conserve the remaining forest and biodiversity of the area. Research to date has focused on birds and mammals, especially carnivores. Primate surveys were conducted for 20 days and 3 nights from July 9–31, 2010. The Napo Tamarin (Saguinus graellsi) was the only primate sighted during the survey and although troops were not habituated every attempt was made to gather data. Tamarins were followed for anywhere from 15 minutes to up to five hours. Tamarins used all levels of the forest, from the ground to the canopy (0–50m) and were seen foraging in both primary and secondary forest as well as along the main road that runs through the reserve (even crossing the road on the ground). Our preliminary data indicate that there are at least three troops, but there may be up to six. Average troop size was four individuals. Several intertroop encounters were observed and consisted of continuous loud chattering vocalizations lasting over 30 minutes in one instance. A number of calls were recorded and will be analyzed in the future. Foraging data gathered indicate that like most other tamarins, the individuals at this site have a mixed diet. Individuals were seen foraging on the flowers of Inga sp. and Mucuna elliptica, fruit of Pourouma cecropiifolia and an unkown liana, and palm exudates. During the study period a dead juvenile male was discovered with few marks. The specimen was measured (HB = 23 cm, T = 32.5 cm, HF = 6.5 cm, E = 2.4 cm) and deposited at Pontificia Universidad Católica del Ecuador in Quito. Although cause of death could not be determined, potential predators at the site include margays, tayras and several raptor species. In addition to the tamarins, four other species of primates have been observed in the reserve: Aotus vociferans, Ateles belzebuth, Cebus albifrons, and Alouatta seniculus. Although not in the reserve Woolly monkeys (Lagothrix lagotricha) do reside in the nearby Sumaco Galeras National Park. Researchers will continue to monitor primates at the site and more behavioral data will be collected in the future. The Wildsumaco Biological Field Station, a joint venture between the preserve, Francis Marion University and University of North Carolina Wilmington, will open in July 2011 and facilitate future primate studies in the area. For more information on primate studies at Wildsumaco please contact Natasha Vanderhoff (nvander4@ju.edu) or visit the website ( http://www.riopucunofoundation.org/).