Data from: Hunting behavior and feeding ecology of Mojave Rattlesnakes (Crotalus scutulatus), Prairie Rattlesnakes (C. viridis), and their hybrids in southwestern New Mexico

Predators must contend with numerous challenges to successfully find and
subjugate prey. Complex traits related to hunting are partially controlled
by a large number of co-evolved genes which may be disrupted in hybrids.
Accordingly, research on the feeding ecology of animals in hybrid zones
has shown that hybrids sometimes exhibit transgressive or novel behaviors,
yet for many taxa empirical studies of predation and diet across hybrid
zones is lacking. We undertook the first such field study for a hybrid
zone between two snake species, the Mojave Rattlesnake (Crotalus
scutulatus) and Prairie Rattlesnake (C. viridis). Specifically, we
leveraged established field methods to quantify hunting behaviors of
animals, their prey communities, and diet of individuals across the hybrid
zone in southwestern New Mexico, USA. We found that, even though hybrids
had significantly lower body condition indices than snakes from either
parental lineage, hybrids were generally similar to non-hybrids in hunting
behavior, prey encounter rates, and predatory attack and success. We also
found that, compared to C. scutulatus, C. viridis was significantly more
active while hunting at night and abandoned ambush sites earlier in the
morning, and hybrids tended to be more viridis-like in this respect. Prey
availability was similar across the study sites, including within the
hybrid zone, with Kangaroo Rats (Dipodomys spp.) as the most common small
mammal both in habitat surveys and frequency of encounters with hunting
rattlesnakes. Analysis of prey remains in stomachs and feces also showed
broad similarity in diets, with all snakes preying primarily on small
mammals and secondarily on lizards. Taken together, our results suggest
that the significantly lower body condition of hybrids does not appear to
be driven by differences in their hunting behavior or diet, and may
instead relate to metabolic efficiency or other physiological traits we
have not yet identified.