Meeting Abstract

P3.14  Wednesday, Jan. 6  Ultimate explanations for differences in learning patterns and decision-making abilities of pitvipers (Viperidae: Crotalinae) KROCHMAL, Aaron R*; LADUC, Travis J.; PLACE, Aaron J.; Washington College; The Universtiy of Texas at Austin; Northwestern Oklahoma University akrochmal2@washcoll.edu

Little effort has been devoted to investigating decision making and learning in snakes. Those studies that have been conducted generally lack biological relevance and a phylogenetic framework, curtailing the scope of these investigations and the results thereof. Recently, we described an experiment in which we investigated the ability of 13 species of pitviper – 7 rattlesnake and 6 non-rattlesnake pitvipers – to escape from a thermally stressful environment. Though all species were able to escape from the stressful environment equally well, rattlesnakes in the study learned to escape in one-trial (i.e., escape in 11 subsequent trials was faster than trial 1), whereas non-rattlesnake pitvipers never decreased their escape time over the 12 trials. We propose two ultimate-level hypotheses explaining the origins of the learning and decision-making ability of rattlesnakes. First, these behavioral abilities could have arisen to aid in navigating a thermal environment that was complex, extreme and variable, an idea supported by behavioral studies and the paleo-climate and habitat structure of the region in which rattlesnakes are thought to have arisen. Alternatively, these abilities might have risen concurrently with the rattle to aid in its appropriate use, and subsequently exapted to assist in thermoregulatory decisions; this hypothesis is supported by some behavioral studies, though recent studies of learning and rattle use do not. By evaluating both hypothesis critically, we aim to determine the most plausible hypothesis explaining the initial adaptive value that drove the evolution of the learning and decision-making abilities of pitvipers.