Influence of sea turtle nesting on hunting behavior and movements of jaguars in the dry forest of northwest Costa Rica

Jaguars (Panthera onca) are opportunistic predators that prey on
large profitable prey items, such sea turtles at nesting beaches. Here we
use jaguar and sea turtle track count surveys, combined with satellite
telemetry of one jaguar, to evaluate whether jaguar hunting behavior and
movements are influenced by seasonal sea turtle nesting in the Sector Santa
Rosa of Área de Conservación Guanacaste in northwest Costa Rica. We used
Generalized Linear Models to evaluate the effect of moon phase and sea
surface temperature on olive ridley (Lepidochelis olivacea) and green
turtle (Chelonia mydas) nesting abundance, as well as the combination of
these predictors on the frequency of jaguar predation activity (proximity
to nesting beaches) and movements. For home range size and location
analyses, we calculated Kernel Density Estimates for each season at three
different temporal scales. Sea turtle nesting season influenced jaguar
activity patterns, as well as sea turtle abundance was related to jaguar
locations and predation events, but jaguar home range size (88.8 km2
overall) did not differ between nesting seasons or among temporal scales.
Environmental conditions influenced sea turtle nesting and, as a
consequence, also influenced jaguar movements and foraging activity. Our
study defined the home range of a female jaguar in the tropical dry forest
and its relationship to seasonally abundant turtles. Additional information
related to the effect of tourism on jaguar-sea turtle interactions would
improve conservation of these species at unique nesting beaches in the area.
Methods
We gathered previous sea turtle nesting data surveys from peer reviewed and technical papers for both Playa Nancite  (1980-2011) and Playa Naranjo (2013 - 2015). When the raw data from turtle nesting surveys was not available we used the R package “digitalize” to retrieve data from old figures (Poisot, 2011). Opportunistic sea turtle track-count surveys also were conducted at Playa Naranjo during 2013-2015.  Each morning we walked along Playa Naranjo at 2 km/hour and registered activity from the previous night; sea turtle track-counts by species, jaguar presence (i.e., jaguar tracks on the beach) and jaguar predation events (i.e., jaguar-killed turtles).  Additional information such moon phase (Lazaridis, 2014) was gathered. We also monitored the movements of a single jaguar.