Meeting Abstract

P2.1  Wednesday, Jan. 5  Habitat-specific adaptations in growth rates play a role in species distribution of Sceloporus lizards in Florida ROBBINS, T.R.*; MUSHINSKY, H.R.; MCCOY, E.D.; The Pennsylvania State University, University of South Florida; University of South Florida; University of South Florida trr11@psu.edu

Habitat-specific adaptations are important in determining subsequent species’ distributions because they often result in fitness trade-offs across environments. We examined habitat-specific adaptations in juvenile growth rates and survival using a reciprocal transplant experiment between species and habitats of the Eastern Fence Lizard, Sceloporus undulatus, and the Florida Scrub Lizard, S. woodi. These species are closely related, with isolated hybridization events occurring where their habitats are adjacent. They exhibit habitat specificity, however, and have remained distinct species in Florida for at least one million years. We also had population-specific minimum size at maturity that could be used to determine whether delayed maturity occurs for these populations in the foreign habitats. Juvenile survival rates allowed us to estimate the probability that individuals from each population will reach the minimum size at maturity in each habitat. Each native species grew faster in their native environment than did the foreign species. Juvenile survival, however, was similar for both species in all environments, which suggests that reproductive isolation does not occur simply through decreased juvenile survival in the foreign environments. When juvenile growth rates and survival were examined together with population-specific minimum size at maturity, however, there were overall habitat-specific adaptations with regard to the probability of reaching size at maturity. Each species had a higher average probability of reaching size at maturity in their native habitats, relative to the foreign species. Therefore, we found home-site advantages in juvenile growth rates and the probability of reaching size at maturity.