Title
Gray marmoset monitoring program in the area of influence of Porce III reservoir (Antioquia): occupancy as an indicator of population change
Author(s)
Gómez-Posada, C.;Henao, B.;Acosta-Castañeda, A.;Bianche, G.;Rojas-Díaz, V.;Forero, G.;Goldstein, I.
Published
2015
Abstract
As part of the gray marmoset (Saguinus leucopus) conservation strategy in Porce III, Empresas Públicas de Medellín EPM and WCS developed a monitoring program to evaluate the responses of marmoset populations to the changes generated in their habitat by the operation of the hydroelectric project. A conceptual framework was established following the open standards methodology, establishing "maintaining or increasing marmoset populations in the long term" as the management objective. Through workshops with experts, "occupation" was determined as the variable to be evaluated. The monitoring objective seeks to establish whether EPM's management strategy, measured as the change in forest cover, is reflected in changes in the area of marmoset occupancy. In 2014, 198 cells of 6.25ha (size area of marmoset activity in the area) were evaluated, with 6 playback/cell, confirming marmoset presence in 61 cells. A probability of detection=0.205 (ES=0.021) and occupancy of 0.367 (ES=0.042) was calculated with a hierarchical one-season model depending on the covariates % forest cover and edge length. The monitoring program was designed suggesting to evaluate 240 cells of 6.25ha and take 12 playback points/cell, in two sampling periods (will allow to detect a 30% change in occupancy over time, with power 0.80 and significance 0.20). Future sampling will indicate how the occupancy of the marmoset population changes as the cover and edges change with the recovery of the forests protected by EPM. Porce III is one of the only two areas with a larger area of continuous and higher quality forest within the distribution of the gray marmoset, which makes it a priority in terms of conservation of this endangered species.
Keywords
Saguinus leucopus;occupancy (presence);adaptive management;monitoring

Access Full Text

A full-text copy of this article may be available. Please email the WCS Library to request.



Back

PUB15513