Population Assessment of the Common Squirrel Monkey (Saimiri sciureus) on Sumak Allpa, Equador

Abstract

Sumak Allpa is a 113.5 hectare-island located within the Ecuadorean Amazon, serving as an active primate sanctuary for imperiled species. In order to measure the current status of the common squirrel monkey (Saimiri sciureus) on Sumak Allpa, I assessed their population and distribution using estimation techniques during 30 observation periods in the spring of 2014. My results indicated three larger troops, one small troop, and one solitary primate, with approximately 55 to 60 individuals currently inhabiting the island. Based on the infrequent displays of aggression observed among the common squirrel monkeys, it was assumed that the troops were not competing for resources. Compared to population counts from 2012, these results suggested a positive growth rate within the common squirrel monkey population of Sumak Allpa. Given this growth rate, it would be beneficial to consider primate reintroduction strategies using the island as a source population.