Meeting Abstract
In territorial birds, both parental and territory quality vary and influence resource allocation to offspring. In our study population of house wrens, evidence of such heterogeneity, its temporal consistency, and its fitness consequences, comes from the historic record of reproductive success at fixed-site nestboxes. To assess the potential effects of habitat heterogeneity independent of parental quality, we tested the hypothesis that territory quality influences female reproductive allocation in house wrens. Territories were categorized into low-, intermediate-, and high-quality based on fledging success the previous 5 years. Entrance size was increased in nestboxes (wrens prefer small entrances) on high-quality territories and on randomly-selected intermediate-quality territories to alter site attractiveness, thereby disrupting any covariation between territory quality and individual quality. Eggs were measured and cross-fostered in pairings between nests on high- or low-quality territories and intermediate-quality territories, to disentangle prenatal and postnatal effects of variation in territory quality. We found that territory quality had minimal effect on measures of parental resource allocation both prenatally and postnatally; however, a strong relationship between current nest success and territory quality persisted. Therefore, other factors of territory quality, such as predation risk, play important roles in determining reproductive success.
