Meeting Abstract
Chronic, sublethal exposure to lead, a common urban contaminant, causes behavioral and physiological problems in humans living in cities, but little is known about the effects of lead exposure on urban wildlife. Our previous work on the northern mockingbird (Mimus polyglottos) in New Orleans suggests that birds in high-lead neighborhoods have higher concentrations of lead in their blood and feathers and are more aggressive. Here, we examine how the reproductive output and cuckoldry rates of mockingbirds may be impacted by lead exposure. On the one hand, more aggressive, high lead males may obtain higher quality territories and resources and mate guard more effectively, leading to high reproductive output and reduced cuckoldry rates within their nests. Conversely, high lead birds may experience reduced reproductive output via direct impacts of lead exposure on the survival of eggs and nestlings, and increased cuckoldry through infertility or excessive aggressive behavior. Our findings provide insights into how lead exposure may mediate fitness via tradeoffs between aggressive behavior, cuckoldry rates, and offspring survival.
