Chestnut-sided Warbler


Common Name:Chestnut-sided Warbler





Species:Setophaga pensylvanica

Photo: Steven Pitt



Chestnut-sided Warblers are passerines in the family Parulidae which consists of New World Warblers. An adult Chestnut-sided Warbler has a yellow crown with a chestnut colored side. They have a black eye line and black moustache. The female does not have as distinct or vivid chestnut side. Both male and female Chestnut-sided Warblers have yellow wing bars. They are 11-14cm and weigh 8-10 grams.


Chestnut-sided Warblers can be found in second growth deciduous forests and in bushy pastures. This means that they are especially common in early successional clear cut areas and abandoned farmlands. This warbler feeds primarily on insects and eats insects that are potentially harmful to crops, helping farmers. The warblers will eat some fruit especially during fall migration and this warbler species will usually be found foraging alone gleaning insects from underneath leaves.




The Chestnut-sided Warbler is highly territorial during the breeding season. It is a nocturnal migrant and may join up with other flocks and forage with them. It can be found hopping on the ground and through foliage.

Chestnut-sided Warblers are monogamous and pairs raise at least one brood per year with some birds re-nesting. The Chestnut-sided Warbler female builds a cup nest out of grass, bark, and plant stems that the females will build entirely by themselves. The average clutch size is four eggs which the female incubates  for 12-13 days.  The young are born altricial which means that they are blind, immobile and helpless. Both parents tend young which fledge 10-12 days after hatching.




The Chestnut-sided Warbler is found through out Western New York especially in bushy and early successional forests during the summer. Areas such like these are found near abandoned  farming/urban areas and also in managed areas such as Iroquois NWR and Wildlife Management Areas.


Birds of Western New York is brought to you by the Institute for the Study of Human-Animal Relations at Canisius College in Buffalo, NY.