Meeting Abstract

94.6  Wednesday, Jan. 7  Phylogenetic perspectives on learning in pitvipers (Viperidae: Crotalinae) with comments on one-trial learning in rattlesnakes KROCHMAL, Aaron R.*; BAKKEN, George S.; LADUC, Travis J.; Washington College, Chestertown MD akrochmal2@washcoll.edu

Little effort has been devoted to investigating 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. As part of an ongoing study on the thermoregulatory behavior of pitvipers (Viperidae: Crotalinae), we surveyed the abilities of 13 pitviper species to navigate a maze based only on thermal cues. We placed snakes in a Y-maze that was held at a stressful but sub-lethal temperature save one extreme end which was held at a favorable temperature, and recorded the time it took the snakes to navigate the maze in each of 6 trials. Using temperature as the motivation and the reward and surveying species across the phylogeny of pitvipers cast our study within a biologically relevant context. Rattlesnakes (7 species) quickly learned to escape the thermal stress (no species-specific differences were seen; trial 1, pooled mean time= 803 sec, 95%CI= &plusmn58 sec; trials 2-6 did not differ significantly from each other, pooled mean time= 72 sec, 95%CI= &plusmn13 sec), while the 6 other species failed to demonstrate this trend (no species- or trial-specific differences were found; mean time trials 1-6 = 837 sec, 95%CI= &plusmn73 sec). Our results show that in the context of thermoregulation, rattlesnakes exhibit one-trial learning, an ability apparently absent in the other pitvipers surveyed. One-trial learning may represent a derived trait in the rattlesnakes, reflecting the unique conditions under which they evolved. These results underscore the importance of considering biological- and phylogenetic relevance when conducting investigations of learning.