Although the young and adult birds have essentially the same general plumage, there are some slight differences. The rusty tipping on this bird’s tertials identify it as a hatching-year bird (adults lack the rusty tipping). By spring this tipping frequently is worn off, and age is best determined by using the presence or absence of a molt limit. As in many birds, the shape of the tail also can be useful in ageing warblers.
Powdermill Nature Reserve’s avian research center is part of Carnegie Museum of Natural History’s biological research station in Rector, Pennsylvania. The research center operates a bird banding station, conducts bioacoustical research, and performs flight tunnel analysis with the goal of reducing window collisions.