Bay-breasted Warbler Life History


Habitat ForestsBreeds in boreal spruce and fir forest. Winters in lowland tropical forest and second growth.Back to top


Food InsectsInsects and spiders, fruit in winter.Back to top


Nest Placement

Nest Tree

Nest Description

Nest an open cup of twigs, bark, lichen, spider web, and plant down; lined with fine rootlets, pine needles, hair, moss, and fine grasses. Placed on limb of dense spruce tree.

Nesting Facts
Clutch Size:4-7 eggs
Egg Description:White or creamy with bold dark spots.
Condition at Hatching:Helpless with sparse brown down.
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Behavior Foliage GleanerGleans insects off leaves and branches in middle part of trees.Back to top


Conservation Low ConcernPopulations of Bay-breasted warbler appear to be decreasing throughout their range. The U.S. has seen a decline of almost 3% per year between 1966 and 2014, resulting in a cumulative decline of 74%, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 9 million birds with 99% breeding and migrating through Canada, and 1% in the U.S. They rate a 12 out of 20 on the Continental Concern score and are a U.S.-Canada Stewardship species. They are not on the 2014 State of the Birds Watch List. Population declines are possibly as result of spraying for spruce budworms, and loss of wintering habitat may be a problem.Back to top


Dunn, J. L. and K. L. Garrett. 1997. A Field Guide to the warblers of North America. Boston, MA: Houghton Mifflin Co.

Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.

North American Bird Conservation Initiative. 2014. The State of the Birds 2014 Report. US Department of Interior, Washington, DC, USA.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxtent Wildlife Research Center 2014b. Available from

Sibley, D. A. (2014). The Sibley guide to birds, second edition. Alfred A. Knopf, New York, USA.

Stephenson, T. and S. Whittle (2013). The Warbler Guide. Princeton University Press, New Jersey, USA. 

Venier, Lisa, Steve Holmes and Janet Mci. Williams. 2011. Bay-breasted Warbler (Setophaga castanea), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

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