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Friday 9 February 2018

The influence of anthropogenic edge effects on primate populations and their habitat in a fragmented rainforest in Costa Rica.

Primates. 2018 Feb 6. doi: 10.1007/s10329-018-0652-0. [Epub ahead of print] Bolt LM1,2, Schreier AL3,4, Voss KA3, Sheehan EA3,4, Barrickman NL5,4, Pryor NP3,4, Barton MC3,4. Author information 1 Department of Anthropology, University of Toronto, 19 Russell Street, Toronto, ON, M5S 2S2, Canada. laurabolt@gmail.com. 2 The Maderas Rainforest Conservancy, P.O. Box 55-7519, Miami, FL, 33255-7519, USA. laurabolt@gmail.com. 3 Department of Biology, Regis University, Denver, CO, 80221, USA. 4 The Maderas Rainforest Conservancy, P.O. Box 55-7519, Miami, FL, 33255-7519, USA. 5 Salt Lake Community College, Salt Lake City, UT, 84123, USA. Abstract When a forest is fragmented, this increases the amount of forest edge relative to the interior. Edge effects can lead to loss of animal and plant species and decreased plant biomass near forest edges. We examined the influence of an anthropogenic forest edge comprising cattle pasture, coconut plantations, and human settlement on the mantled howler (Alouatta palliata), white-faced capuchin (Cebus capucinus), Central American spider monkey (Ateles geoffroyi), and plant populations at La Suerte Biological Research Station (LSBRS), Costa Rica. We predicted that there would be lower monkey encounter rate, mean tree species richness, and diameter at breast height (DBH) in forest edge versus interior, and that monkeys would show species-specific responses to edge based on diet, body size, and canopy height preferences. Specifically, we predicted that howler monkeys would show positive or neutral edge effects due to their flexible folivorous diet, large body size, and preference for high canopy, capuchins would show positive edge effects due to their diverse diet, small body size, and preference for low to middle canopy, and spider monkeys would show negative edge effects due their reliance on ripe fruit, large body size, and preference for high upper canopy. We conducted population and vegetation surveys along edge and interior transects at LSBRS. Contrary to predictions, total monkey encounter rate did not vary between the forest edge and forest interior. Furthermore, all three species showed neutral edge effects with no significant differences in encounter rate between forest edge and interior. Interior transects had significantly higher mean tree species richness than edge transects, and interior trees had greater DBH than edge trees, although this difference was not significant. These results suggest that forest edges negatively impact plant populations at La Suerte but that the monkeys are able to withstand these differences in vegetation. KEYWORDS: Alouatta; Anthropogenic; Ateles; Cebus; Costa Rica; Edge effects; Forest fragmentation PMID: 29411160 DOI: 10.1007/s10329-018-0652-0