Jaguar (Panthera onca) activity on the beach of Tortuguero National Park, Costa Rica

Abstract:

The jaguars (Panthera onca) of Tortuguero National Park, Costa Rica, sometimes kills and eats green sea turtles (Chelonia mydas), they also, though less often, kill and eat leatherback sea turtles (Dermochelys coriacea). The three species are considered endangered and are listed in CITES. It was the aim of this study to find out more about the jaguars behaviour in the area. To discern any patterns of jaguar and turtle activity on the beach the number of tracks per eighth of a mile was recorded on a daily basis for 26 days and then analyzed. It was also considered to be of interest to determine how many jaguars could be responsible for the predation of sea turtles. In addition to this average beach width was measured for each eighth of a mile. There was a noticeable difference in jaguar activity on the beach between days of recording. Analysis found that the beach width could possibly have a small positive effect on jaguar activity. No correlation was found between jaguar and turtle activity. It is believed that the reason that there was no correlation between jaguar activity and turtle activity was due to most of the tracks used to estimate turtle activity had originated from leatherback turtles, which are not as often predated by jaguars as the green turtle. An estimation of five or six jaguars was made using photographs of pugmarks and a method of track discrimination together with information from personnel from the Jalova station.