Estación Biológica Cocha Cashu
Giant Otter Feeding Ecology
Investigator: Lisa Davenport,
A giant otter feeding ecology and predator/prey interactions project is starting up at the Estacion Biologica Cocha Cashu (EBCC) in Manu National Park, Peru. The project aims to fill gaps in the knowledge about Giant Otters feeding ecology in the Manu's oxbow lakes by
1) better describing lake microhabitats and the changes in otter feeding behavior and hunting success with respect to these microhabitats;
2) conducting long-term monitoring of fish populations (pictures of Darwin Osorio Lescano©2002) that are heavily used by otters; and
3) trying to understand the predator/prey interactions between giant otters and their prey (i.e. "top-down" vs. "bottom-up" effects).
The project will be conducted over the next 5-10 years and form the basis of a PhD thesis for the project's primary instigator, Ms. Lisa Davenport. Lisa is just beginning a PhD in Biology under animal behavioralist Dr. Haven Wiley of the University of North Carolina. She is also married to Cocha Cashu's long-time Director, Dr. John Terborgh, and so hopes to return to Cocha Cashu yearly to continue observing otters and monitoring fish populations in Cocha Cashu and other nearby lakes. Lisa is collaborating on the project with Blgo. Ciprian Aguirre, the former head of Fisheries Management in Puerto Maldonado. Ciprian has a long history of working with both wild and captive fish from the area, including long-term research on "boca-chico" a favored fish of both otters and humans. Ciprian hopes to work with the project on a long-term basis, and also conduct a complimentary project studying boca-chico migrations throughout the Manu. The feeding ecology study is only in its early stages. In the fall of 2000 Lisa and Ciprian attempted to begin studying fish populations using electrofishing techniques, but due to equipment failure were only able to collect very preliminary data on relative fish abundances. Instead, they concentrated on mapping Cocha Cashu and neighboring Cocha Totora, and experimenting with different tagging methods for their larger catch-release studies of boca-chico and bujurki. Lisa returned in the summers of 2001, 2002 and 2003 and has been collecting data of fish populations and otter feeding behavior in different lake habitats.