Meeting Abstract

90-4  Saturday, Jan. 6 10:45 - 11:00  Does City Living Lead to Slower Pace of Life: Urban Impacts on Avian Life-History Evolution SEPP, T*; GIRAUDEAU, M; MCGRAW, K; KAASIK, A; Arizona State University; Arizona State University; Arizona State University; University of Tartu

The concept of a pace-of-life syndrome describes inter- and intra-specific variation in several life-history traits along a slow-to-fast pace-of-life continuum, with long lifespans, low reproductive and metabolic rates, and elevated somatic defences at the slow end of the continuum and the opposite traits at the fast end. Previous studies have shown that pace-of-life can vary in relation to local environmental conditions (e.g. latitude, altitude). I propose that this may also occur along an anthropogenically modified environmental gradient. I present the results of a statistical meta-analysis of two key traits related to pace-of-life, survival and breeding investment (clutch size). These results indicate that birds generally have higher survival, but smaller clutch sizes, in urban habitats. I also analyzed the literature on other traits related to reproductive investment and self maintenance that could be affected by changes in pace-of-life resulting from urbanization. I found that urban birds tend to produce lower-quality sexual signals and invest more in offspring care. Levels of nutritional or hormonal stress in birds do not seem to vary consistently as a function of urbanization, which is consistent with the hypothesis that birds can adapt or acclimate to certain aspects of the urban habitat. As a consequence of slower pace-of-life in urban habitats, differences in age structure should arise between urban and rural populations, providing a novel alternative explanation for physiological differences and earlier breeding recorded in urban animals. I also present preliminary results from a field experiment designed to reveal the possible changes in pace-of-life in response to urbanization in a model organism of urbanization research, the house finch (Haemorhous mexicanus).