Evolution of Life Histories in Garter Snakes Correlations among Performance, Morphology, and Behavior


Meeting Abstract

P3.48  Tuesday, Jan. 6  Evolution of Life Histories in Garter Snakes: Correlations among Performance, Morphology, and Behavior MORRILL, Matthew*; BRONIKOWSKI, Anne; Iowa State University; Iowa State University angmar@iastate.edu

Performance has been shown to be strongly correlated with fitness in reptiles, including garter snakes, and performance measures early in life reflect later trends. Anti-predator behavior and pattern morphology have been shown to be strongly correlated with each other and with fitness. We measured performance, anti-predator behaviors, and dorsal patterning in lab-reared juveniles from closely-related populations of western terrestrial garter snake, T. elegans, representing two life history ecotypes. High elevation, meadow (M-slow) snakes grow slow, mature late, and live long (median lifespan 8 yrs), and low elevation, lakeshore (L-fast) snakes grow fast, mature early, and die young (median lifespan = 4). In addition, the two ecotypes have been shown to differ across a suite of other traits. The purpose of this study was to determine if the two ecotypes differed in traits related to predator avoidance to ask what are the ecological forces underpinning the evolution of anti-predator characters. Dorsal pattern was strongly correlated to ecotype with L-fast snakes being more patterned (i.e. checkered or spotted) and M-slow snakes being generally solid. Both performance and reversal behaviors were influenced by ecotype: L-fast snakes were faster and reversed less than M-slow snakes. Stopping behavior (coiling) was not influenced by ecotype, pattern, or sex. We discuss these results in the context of the ecology and evolutionary history of lakeshore and meadow populations.

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