Tuesday, August 5, 2008

PS 19-38: Form matches function or beauty is skin deep? Correlations between coloration and performance in Thamnophis elegans - CANCELLED

Matthew C. Morrill, Iowa State University

Background/Question/Methods

Brodie (2003) found a correlation between stripedness and performance (speed) in Thamnophis ordnoides suggestive of correlational selection. We compare dorsal stripe color, background pattern and correlated performance in populations of Thamnophis elegans representing disinct lifehistory ecotypes: lakeshore populations characterized by fast growth, high reproductive output and early mortality; and meadow populations characterized by slow growth, low reproductive output, and late mortality. Gravid females were collected from populations representing both ecotypes in summer 2006. Mothers were released postparturition and neonates were housed individually. Dorsal stripe color and pattern were assessed visually and placed into categories. Performance was measured using a one meter track with motion sensors at quarter-meter intervals. Track times are given as size dependent (length and mass).   

Results/Conclusions

Lakeshore snakes are more variable in dorsal stripe color and predominantly spotted in their background pattern. Conversely, meadow snakes were less variable in dorsal stripe color and predominantly solid in their background pattern. Lakeshore snakes had faster mean run times than meadow snakes. Analyses of correlation and comparisons to Brodies results are forthcoming and will be presented.