Meeting Abstract
Heavy metals are found naturally in the environment but can be elevated beyond normal levels due to anthropogenic activities. Heavy metals continue to pollute many ecosystems in spite of emission control measures, potentially due to historical exposure or the continued expansion of human development. Organisms exposed to metal pollutants may be negatively impacted if fitness is reduced. The spread of metal pollutants into important ecological systems demands biological indicators that give insight into the local environmental health. Carotenoid-based bright plumage in many songbird species is thought to be a visual cue to potential mates – signaling high fitness levels. This is because bright plumage may reflect efficient foraging for diet-dependent carotenoids and/or the ability to allocate carotenoids to plumage coloration as opposed to anti-oxidant protection. Studies have shown a decline in carotenoid-based coloration along metal pollution gradients, and an increase in melanin patch size with increased metal exposure. We will relate plumage coloration characteristics of urban and rural American Goldfinches (Spinus tristis) and American Robins (Turdus migratorius) to feather mercury levels. Identifying negative impacts of pollutants on wild animals are important for understanding the consequences of anthropogenic activities on wildlife.
