Feeding Ecology of the Milksnake ( Lampropeltis triangulum , Colubridae) in the Western United States

Hunting behavior and feeding ecology of Mojave rattlesnakes (Crotalus scutulatus), prairie rattlesnakes (Crotalus 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 are lacking. We undertook the first such field study for a hybrid zone between two snake species, the Mojave rattlesnake (Crotalus scutulatus) and the prairie rattlesnake (Crotalus viridis). Specifically, we leveraged established field methods to quantify the hunting behaviors of animals, their prey communities, and the 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 group, 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 the 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.

Pet snakes illegally marketed in Brazil: Climatic viability and establishment risk

Invasive species are one among many threats to biodiversity. Brazil has been spared, generically, of several destructive invasive species. Reports of invasive snakes' populations are nonexistent, but the illegal pet trade might change this scenario. Despite the Brazilian laws forbid to import most animals, illegal trade is frequently observed and propagules are found in the wild. The high species richness within Brazilian biomes and accelerated fragmentation of natural reserves are a critical factors facilitating successful invasion. An efficient way to ease damages caused by invasive species is identifying potential invaders and consequent prevention of introductions. For the identification of potential invaders many factors need to be considered, including estimates of climate matching between areas (native vs. invaded). Ecological niche modelling has been widely used to predict potential areas for invasion and is an important tool for conservation biology. This study evaluates the potential geographical distribution and establishment risk of Lampropeltis getula (Linnaeus, 1766), Lampropeltis triangulum (Lacépède, 1789), Pantherophis guttatus (Linnaeus, 1766), Python bivittatus Kuhl, 1820 and Python regius (Shaw, 1802) through the Maximum Entropy modelling approach to estimate the potential distribution of the species within Brazil and qualitative evaluation of specific biological attributes. Our results suggest that the North and Midwest regions harbor major suitable areas. Furthermore, P. bivittatus and P. guttatus were suggested to have the highest invasive potential among the analyzed species. Potentially suitable areas for these species were predicted within areas which are highly relevant for Brazilian biodiversity, including several conservation units. Therefore, these areas require special attention and preventive measures should be adopted.