Pine Warbler    Dendroica pinus

Migratory Status: Short-distance migrant

PIF Population Estimate: 11 000 000

Percent of western hemisphere population breeding in boreal forest: <25%

BAM Effective Detection Radius (m) : 69.65

PIF Maximum Detection Distance (m) : 125

Canadian BBS Population trend: 5.0 n.s. (-0.9 to 10.9)

Life History

Pine Warblers are the only North American wood-warbler that winter almost exclusively north of the Mexican border. A hardy species, it is capable of surviving short periods of cold weather, but primarily winters in areas where mean minimum temperatures remain above –1° C. In winter, Pine Warblers regularly consume seeds and will forage at bird feeders. As a result of its short winter migration, Pine Warblers are among the earliest warblers to arrive in spring and the latest to depart in autumn.

The Pine Warbler is a large, non-descript wood-warbler. Adult males are olive-green above with a yellow throat and breast, black streaking on flanks, white belly, and dark wings with two white wing-bars. Adult females are duller and paler than males with a mottled olive-yellow throat and breast. Immature birds are similar to adult females, but have more olive-brown colouring. The song is a high trill and consists of a simple series of rapid musical notes given at the same frequency. Pine Warblers are one of the few North American passerines that sing during all months of the year; the reason for this behaviour is unclear.

The breeding range is limited to the eastern half of North America and is fragmented and discontinuous. Pine Warblers breed from Florida and the Gulf Coast north to southern Ontario and Quebec, southeastern Manitoba and southwest Ontario, and locally in southwestern New Brunswick. South of the Great Lakes to Tennessee and Virginia, breeding distribution is patchy and in some areas, the species is absent. Populations in the south-eastern United States are residents, while populations further north are migratory. Winter ranges of the northern populations overlap with the breeding range of the southern population.

Pine Warblers breed in a variety of upland habitats dominated by pine (Pinus spp.). Adults are commonly found in pine plantations, though young, dense plantations generally support fewer birds. Pine Warblers will also nest in areas of deciduous forest that have scattered or small groves of pine. Typically, Pine Warblers are more common in habitats with a sparse understorey and are absent at higher elevations. Pine Warblers nest high in pine trees, making nests difficult to observe and, as a result, little is known about their breeding habits.

Reference(s)

Rodewald, P. G., J. H. Withgott and K. G. Smith. 1999. Pine Warbler (Dendroica pinus), The Birds of North America Online, . A. Poole, Ed. Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: http://bna.birds.cornell.edu/bna/species/438