- 4.3–5.1 in
- 6.7–7.9 in
- 0.3–0.4 oz
- Paruline bleue à gorge noire (French)
- Reinita azul negra (Spanish)
- The sexes of the Black-throated Blue Warbler look so different that they were originally described as two different species.
- On the wintering grounds the sexes use slightly different habitats. The male is most common in forest at lower to mid-elevations, while the female uses shrubbier habitat at higher elevations.
- The oldest Black-throated Blue Warbler was a female and at least 9 years, 8 months old. She was banded in New Jersey in 1975 and shot in Panama in 1985.
- Breeds in mature deciduous and mixed coniferous-deciduous woodlands with a thick understory, often in hilly or mountainous terrain.
- Winters in dense tropical forests.
- On migration, found in variety of habitats, including forest, forest edges, parks, and gardens.
Insects and some small fruits.
- Clutch Size
- 2–5 eggs
- Egg Description
- Creamy white with dark speckles concentrated at the large end.
- Condition at Hatching
- Helpless with tufts of down.
Nest an open cup of strips of bark, held together with spider web and saliva. Places in fork of low shrub.
Forages mostly in lower to mid-levels of forest, taking insects mostly from the underside of leaves.
Black-throated Blue Warbler populations are stable and increased between 1966 and 2015, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 2.1 million, with 65% breeding in Canada, 35% spending some part of the year in the U.S., and 2% in Mexico. The species rates a 9 out of 20 on the Continental Concern Score, and is not on the 2016 State of North America's Birds' Watch List. Black-throated Blue Warbler numbers probably decreased markedly with destruction of eastern forests in 17th and 18th centuries, but with the beginning of abandonment of farms in New England in the late 19th and 20th centuries, populations rebounded.
- Holmes, R. T. 1994. Black-throated Blue Warbler (Dendroica caerulescens). In The Birds of North America, No. 87 (A. Poole, and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
- North American Bird Conservation Initiative. 2016. The State of North
America’s Birds 2016. Environment and Climate Change Canada: Ottawa, Ontario.
- Partners in Flight. 2012. Species assessment database.
- Sauer, J.R., J.E. Hines, J.E. Fallon, K.L. Pardieck, D.J. Ziolkowski, Jr., and W.A. Link. 2016. The North American Breeding Bird Survey, Results and Analysis 1966–2015, Version 01.30.2015. USGS Patuxent Wildlife Research Center, Laurel, MD.
- USGS Patuxent Wildlife Research Center. 2016. Longevity records of North American Birds.