Meeting Abstract

P3.1  Saturday, Jan. 5  Ectoparasite Load, Fecundity, and Brood Survivorship in Barn Swallows (Hirundo rustica). ROGERS, Stacey; CORBIN, Clay; WASSMER, Gary*; Bloomsburg University of Pennsylvania; Bloomsburg University of Pennsylvania; Bloomsburg University of Pennsylvania gwassmer@bloomu.edu

Parasites extract nutrients from their host. Hence, high levels of parasitism are expected to be associated with reduced reproduction. Barn swallows and their nests house a variety of ectoparasites due, in part, to coloniality and nest reuse. We hypothesized that nests with high parasite loads would have decreased reproductive success as measured by the number of broods and the survivorship to fledging. A total of 640 eggs from 429 nests where observed every 2-3 days at 11 study sites in central Pennsylvania from April to September 2005. For each site, the timing and number of eggs, the number of hatchlings, and the number of fledglings was recorded. Additionally, parasite loads were estimated for each nest and each brood. We predicted 1) high rates of nest ectoparasites would be negatively correlated with the number of broods per nest and 2) nest ectoparasite abundance would be positively correlated with high pre-fledging mortality. As hypothesized, high parasitism rates were associated with single broods, and nests with no or few parasites were more likely to support multiple broods. Surprisingly, however, high rates of parasitism were correlated with high brood survivorship. We propose several hypotheses that may explain these results.