Jaguars (Panthera onca) increase kill utilization rates and share prey in response to seasonal fluctuations in nesting green turtle (Chelonia mydas mydas) abundance in Tortuguero National Park, Costa Rica

Abstract

Jaguar (. Panthera onca) predation of green turtles (. Chelonia mydas mydas) is now a common occurrence in Tortuguero National Park, Costa Rica. The abundance of green turtles during nesting season ensures a constant provision of easy and predictable prey, however it is unknown to what extent jaguars consume turtle carcasses and how the jaguar population responds to limited turtle availability outside of nesting season. This study took advantage of the accessible nature of jaguar-predated turtle carcasses on Tortuguero Beach over a two year period (2011-2013), to provide a novel analysis of carcass utilization rates by jaguars and determine the effects of temporal fluctuations in green turtle nesting numbers. Camera traps were set-up on freshly predated turtles to capture jaguar activity across both Peak and Non Peak green turtle nesting seasons. Thirteen individual jaguars (five males, five females, three cubs) were captured returning to 77% of monitored turtle kills (60% Peak; 95% Non Peak). During Non Peak season, the number of jaguars per kill increased (. H(1). =. 15.91, p<. 0.001) and total jaguar feeding time per kill also increased (. H(1). =. 13.34, p<. 0.001). The propensity for tolerated scavenging or sharing during Non Peak season is illustrated by four adult jaguars captured interacting with a kill at separate times over two nights in October, 2012 (two males, two females). There were no significant differences between males and females, although there is a tendency for the latter to handle the prey to a greater extent. Although marine turtles may not to be a primary prey species, they play an important role in subsidizing the jaguars in this study. The increased kill utilization rates and prey sharing displayed by the jaguars, ensures optimal foraging during periods of low prey availability. These apparently atypical feeding behaviors may be unique to Tortuguero, however their prevalence across the jaguar's range should be considered.

La depredación de tortugas verdes (. Chelonia mydas mydas) por parte de jaguares (. Panthera onca) es un hecho común en el Parque Nacional Tortuguero, Costa Rica. La abundancia de tortugas verdes durante la temporada de anidación asegura una provisión constante de presas fáciles y predecibles, sin embargo se desconoce hasta qué punto los jaguares consumen cadáveres de tortugas y cómo responde la población de jaguares a la disponibilidad limitada de tortugas fuera de la temporada de anidación. Este estudio aprovechó la naturaleza accesible de los cadáveres de tortugas depredados por jaguares en Playa Tortuguero durante un período de dos años (2011-2013), para proporcionar un nuevo análisis de las tasas de utilización de los cadáveres por los jaguares y determinar los efectos de las fluctuaciones temporales en los números de anidación de la tortuga verde. Se colocaron cámaras trampa en tortugas recién depredadas para capturar la actividad de los jaguares durante las temporadas pico y no pico de anidación de tortugas verdes. Trece jaguares individuales (cinco machos, cinco hembras, tres cachorros) fueron capturados regresando al 77% de las muertes de tortugas monitoreadas (60% Pico; 95% No Pico). Durante la temporada No Pico, el número de jaguares por muerte aumentó (. H(1). =. 15.91, p<. 0.001) y el tiempo total de alimentación del jaguar por muerte también aumentó (. H(1). =. 13.34, p<. 0.001).