Meeting Abstract

66.4  Sunday, Jan. 6  Pond Canopy Cover Induces a Trade-off in Terrestrial Locomotor Abilities of Post-metamorphic Toads (Bufo americanus) PURRENHAGE, Jennifer L*; GERALD, Gary W; COLLINS, Andrea M; Miami University purrenjl@muohio.edu

Many amphibians have a complex life cycle comprising aquatic and terrestrial stages. Following metamorphosis, juveniles emigrate from ponds to upland habitats, and are faced with various threats including desiccation and predation. Consequently, locomotor performance is extremely important for post-metamorphic individuals. Past studies have identified thermal sensitivity and gender as major determinants of locomotor ability in amphibians. However, terrestrial locomotor ability may also be influenced by the amphibians� larval experience. Larvae from open- and closed-canopy ponds experience different environmental conditions (e.g., light, temperature, DO, vegetation, food quantity), which may affect subsequent performance in the terrestrial stage. We raised American Toad (Bufo americanus) and Spotted Salamander (Ambystoma maculatum) larvae in cattle-tank mesocosms representing open-canopy and closed-canopy pond habitats to test the hypothesis that metamorphs from open-canopy ponds exhibit superior locomotor ability (i.e., speed and endurance) compared to metamorphs from closed-canopy ponds. We found no significant effect of pond type on speed or endurance in A. maculatum. However, B. americanus from closed-canopy ponds exhibited faster burst speeds than those from open-canopy ponds. Faster burst speeds of B. americanus were attributed to an increase in hop frequency rather than an increase in hop distance. In contrast, we found that B. americanus from open-canopy ponds exhibited greater endurance than those from closed-canopy ponds. Our results suggest that for B. americanus, pond habitat type directly or indirectly stimulates a trade-off between speed and endurance to ensure the best chance of survival in the terrestrial habitat to be encountered.