Meeting Abstract

88.5  Friday, Jan. 7  Oxidative damage reduces reproductive output in the cooperatively breeding Florida Scrub-Jay HEISS, Rebecca S. *; SCHOECH, Stephan, J. ; University of Memphis rsheiss@memphis.edu

Oxidative damage results from the inability of an organism to cope with reactive oxygen species, formed as byproducts of metabolism. The resulting damage to various classes of biomolecules has been implicated in both debilitating diseases and cellular senescence. Using the cooperatively breeding Florida Scrub-Jay (Aphelocoma coerulescens), we tested several predictions regarding oxidative damage and life history. Specifically, we predicted that oxidative damage would: 1) increase with age; 2) alter reproductive output; and 3) increase with reproductive effort. Oxidative damage levels were assessed both prior to, and post breeding. Birds were divided into 5 age categories: 0 (nestlings), 1, 2-5, 6-9, 10+ yr of age. Oxidative damage levels were significantly lower in nestling birds, relative to 1, and 2-5 year old birds. The significant increase in oxidative damage between young birds before their first breeding attempt and age categories after, suggests that the first breeding season results in relatively higher oxidative damage than subsequent years in which breeders are more experienced or better prepared. Males, but not females, with relatively higher levels of pre-breeding oxidative damage, demonstrated significantly less reproductive effort as measured by the pairs’ number of eggs, nestlings and successful fledglings. Reproductive effort was not correlated with post-reproduction oxidative damage levels in either sex, although subsequent years of data may be necessary to rule out inter-annual environmental effects. The pre-breeding oxidative damage levels of males may underlie a signal of quality, influencing female reproductive investment. Feather reflectance as a potential signal of oxidative damage and the influence of antioxidant availability on reproductive effort will be discussed.