Integrating fecal isotopes and molecular scatology to non-invasively study the spatial ecology of elusive carnivorans: a case study with wild jaguars (Panthera onca)

Abstract

Monitoring landscape use for large, solitary carnivorans like jaguars is challenging due to their elusive nature and the substantial survey efforts required. We combined non-invasive molecular and isotopic analysis of fecal (scat) samples to evaluate landscape use for jaguars at the Mountain Pine Ridge Forest Reserve (MPR) in Belize during the summer of 2007. Molecular scatology can assign scats to genetically distinct individual predators, and when combined with the geographic location of scats, it is possible to estimate the area of use (AoU) for each identified individual and the spatial overlap between individuals. Fecal isotope values augment molecular scatology by clarifying where consumed prey spent their time and thus where individual predators may have foraged. We collected 80 jaguar scats, most of which were genetically assigned to four males (called jaguars 1, 2, 3, and 5), and analyzed carbon, nitrogen, and strontium isotopes for a subset of 23 scats. The location of scats alone demonstrates that multiple jaguars regularly spent time in central MPR. Both AoU estimates and isotopic data clarify that jaguars 1 and 2 had considerable spatial overlap in central MPR, while jaguar 3 likely stayed closer to the northern edge of MPR, and jaguar 5 foraged more in the south/southeast of the reserve. Combining these complementary tools makes for a powerful, non-invasive wildlife survey approach that could help address various conservation challenges.