Post-Metamorphic Carry-Over Effects in a Complex Life History: Behavior and Growth at Two Life Stages in an Amphibian, Anaxyrus fowleri

Carry-over effects, which occur when an animal's early life experience has lasting effects on its later life, may be manifested in an animal's behavior, growth, and fitness, and are often overlooked as contributing factors to such aspects of animal ecology. Metamorphosis is a process that can produce such effects in animals with complex life histories, due to the significant energetic cost and physical changes undergone during this process. We explored the potential impact of tadpole density after metamorphosis in a pond-breeding amphibian, Anaxyrus fowleri. If larval density induces carry-over effects, then there should be a positive correlation in behavior and/or relative growth rate between pre-metamorphic tadpoles and the same animals as post-metamorphic toadlets. We raised tadpoles at six density levels, ranging from 0.08 tadpoles/L to 1.67 tadpoles/L, designed to produce variation in growth rate and toadlet size, and quantified relative activity by monitoring movement per five-second intervals in ta...