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Worm-eating Warbler Life History


Habitat Forests

  • Breeds in mature deciduous or mixed deciduous-coniferous forest with patches of dense understory, usually on steep hillside.
  • Winters in tropical forests.
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Food InsectsArthropods, spiders, slugs, and especially caterpillars.Back to top


Nest Placement

Nest Ground

Nest Description

Nest a cup of skeletonized leaves lined with moss, placed on ground.

Nesting Facts

Clutch Size:4-6 eggs
Number of Broods:1 brood
Egg Length:0.6-0.8 in (1.63-1.91 cm)
Egg Width:0.5-0.7 in (1.31-1.65 cm)
Incubation Period:11-17 days
Nestling Period:9-11 days
Egg Description:White to pink, with brown speckles.
Condition at Hatching:Helpless and naked.
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Behavior Foliage GleanerGleans in low shrubs, but only rarely on ground. Probes into hanging dead leaf clusters and foliage.Back to top


Conservation Low ConcernOverall, Worm-eating Warbler populations remained stable between 1966 and 2014 - with some areas experiencing declines, and others, increases - according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 830,000, with 100% breeding in the U.S., and 35% wintering in Mexico. This is a U.S.-Canada Stewardship species, and rates a 12 out of 20 on the Continental Concern Score. Worm-eating warbler is not on the 2014 State of the Birds Watch List. Dependence on large forests for nesting make this species vulnerable to population decreases due to habitat loss.Back to top


Lutmerding, J. A. and A. S. Love. (2019). Longevity records of North American birds. Version 1019 Patuxent Wildlife Research Center, Bird Banding Laboratory 2019.

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, NY, USA.

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

Vitz, Andrew C., Lise A. Hanners and Stephen R. Patton. (2013). Worm-eating Warbler (Helmitheros vermivorum), 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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