Meeting Abstract
P2.43 Saturday, Jan. 5 Response of Prey to Evolutionarily Novel Predators with a Constraint-Breaking Adaptation: What do gerbils think of sidewinder rattlesnakes? BLEICHER, S.S*; KOTLER, B.P; BROWN, J.S; University of Illinois at Chicago; Ben-Gurion University of the Negev; University of Illinois at Chicago bleicher.s.s@gmail.com
We investigated three evolutionary concepts: 1.Convergent evolution between North American and Middle Eastern desert vertebrates. 2.Constraint breaking adaptations in invasive species, and 3.Prey species acclimation to an evolutionarily novel predator? In an aviary we exposed Allenby’s gerbils ( Gerbillus andersoni allenbyi) to known predators: red foxes, barn owls and Saharan horned vipers (Cerastes cerastes). We also exposed the gerbils to an evolutionarily novel predator, the Sidewinder Rattlesnakes (Crotalus cerastes) from North America. In addition to being novel, they possess heat sensory pits, a potentially constraint breaking adaptation over the native predator. Using optimal patch use theory, we quantified the gerbils’ responses to each of the snake species prior to, during, and immediately after spending time in the aviary. At “entry” and “exit” the gerbils were exposed non-lethally to the snakes to measure instinctive fear. During the 60 day trial in the aviary the predators were not restrained. At entry, the gerbils recognized the evolutionarily novel rattlesnake as lesser a threat than the native horned viper. During the two months of experiments in the vivarium the gerbils learned to assess the risks posed by the novel predator. The gerbils showed a stronger response to the sidewinders at exit. Our experiment suggests that in the case of the horned viper versus the pit-viper rattlesnake, the gerbils learned how to behave in the presence of the evolutionarily novel predator. The gerbils assessed the behavior of the snake. This was shown by change in behavior between moon phases. Our observations showed that the constraint breaking adaptation does not give the sidewinder a clear advantage against the gerbils as a pray species.
