SREL Reprint #2518

 

 

 

Phenotypic plasticity in reproductive traits: geographical variation in plasticity in a viviparous snake

R. A. Seigel1 and N. B. Ford2

1Southeastern Louisiana University, Department of Biological Sciences, Hammond, LA 70402-0736, USA
2University of Texas-Tyler, Department of Biology, Tyler, TX 75701, USA

Summary:
1. Previous experiments showed that Checkered Garter Snakes (Thamnophis marcianus) from south Texas, USA (an environment subject to high seasonal and annual variation in environmental conditions), demonstrated marked phenotypic plasticity in clutch size and clutch mass in response to experimental changes in prey availability.
2. In this study, the extent of phenotypic plasticity in life-history traits in Checkered Garter Snakes from south Texas was experimentally compared with a population of the same species from south-eastern Arizona, where the environment may be more constant.
3. Unlike results from south Texas, Checkered Garter Snakes from Arizona showed no significant phenotypic plasticity in clutch size, clutch mass or any other life-history trait in response to changes in food availability, at least within the boundaries of our experimental conditions.
4. The data indicate that the degree of phenotypic plasticity in life-history traits differs among populations within the same species. However, these differences are subject to both adaptive and non-adaptive explanations.

Keywords: Fecundity, geographic variation, phenotypic plasticity

SREL Reprint #2518

Seigel, R. A., and N. B. Ford. 2001. Phenotypic plasticity in reproductive traits: geographical variation in plasticity in a viviparous snake. Functional Ecology 15:36-42.

To request a reprint

 

 
http://srel.uga.edu www.uga.edu