Meeting Abstract

P2.6  Wednesday, Jan. 5  Sexually-dimorphic niche and character displacement of the green anole (Anolis carolinensis) in the presence of the invasive Cuban brown anole (Anolis sagrei) SMITHERS, C.A.*; HSIEH, S.T.; Temple University, Philadelphia; Temple University, Philadelphia cherice@temple.edu

Although adaptation tends to be a slow and gradual process, natural or anthropogenic changes can be extremely rapid and unpredictable. Species invasions offer unique opportunities to study long and short-term dynamics of rapid population response to environmental change. Intraspecific competition between invasive and native species can lead to niche and character displacement of the native species and restructuring of the natural community. Previous research has indicated that competition between native green anole lizards and invasive brown anole lizards in the southeast United States has led to population declines and possible niche displacement of the green anole. Our preliminary results comparing existing green anole populations on islands with and without brown anoles in Florida show that invaded populations of green anoles on average utilize higher and narrower perches than uninvaded populations. We hypothesized that this habitat shift would result in decreased limb lengths and restructuring of head dimensions to reflect changes in habitat and diet. We measured head and limb dimensions for over 500 live and preserved specimens from Florida and Georgia, and estimated brown anole invasion years for each county from museum collection databases. Our results show that after the invasion of the brown anole, female hindlimb length decreased and head width and head depth increased for both sexes. Our results suggest that brown anole-induced niche displacement has influenced the evolutionary trajectory of the green anole lizard in a sexually dimorphic manner, resulting in more detectable morphological changes in females than in males.