Chestnut-sided warbler Dendroica pensylvanica

Identification Tips:

• Length: 4.25 inches
• Small, active, insect-eating bird
• Yellow wing bars
• Thin, pointed bill
• Black legs

Adult male alternate:

• Yellow crown
• White patch on side of neck surrounded by thick black eyeline and black malar streak
• Black malar streak connects with thick rusty stripe on side
• White underparts
• Black back with white streaks
• Female in alternate plumage similar to male but duller with reduced rust on sides

Basic and immature:

• Green crown, nape and back
• Gray face and sides of breast
• White eye ring
• White belly and undertail coverts
• Some rust may be present on sides

Similar species:

In alternate plumage, the only other warbler with rusty sides is the Bay-breasted Warbler but it has a brown, not yellow, crown and has a dark throat. In basic (fall) and immature plumages the yellow wing bars can also be found in the Golden-winged Warbler but this species has a dark throat and cheek patch. The white eye ring, unstreaked underparts, and gray face are also good field marks.

Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.