The Black-and-white Warbler is well known for its habit of creeping along tree branches and trunks to forage for insects in the bark [e.g. Morse 1989]. It generally prefers mature and second-growth deciduous forests although it may frequent a variety of other habitats during migration and in winter [Kricher 1995 (BNA)]. Primarily an eastern species, its breeding range extends in the south from eastern Texas to North Carolina, north to Newfoundland [BNA]. It is also widely distributed in central and western Canada. The wintering range is quite extensive, including areas of the southern U.S., the Caribbean Islands, Mexico, Central America, and northern South America [Kricher 1995 (BNA)].
Both spring and fall migration are prolonged in this species. Tyler, in Bent’s [1953] Life Histories, suggests that the Black-and-white Warbler is able to arrive earlier in spring and depart later in fall than other warblers due to its feeding habits. Because it forages for insects primarily in the bark, whether or not a tree has leaves is of little consequence to this species. Spring migrants pass through the U.S. in a broad front [Dunn and Garrett 1997], typically reaching the southern U.S. by early March [Lincoln and Peterson 1979, Moore et al. 1990] and New England by late April [Veit and Petersen 1993]. Migration occurs at night and Black-and-white Warblers can often be found in mixed species flocks as they forage during the day [Kricher 1995 (BNA)]. During migration, they occupy a wide variety of habitats, from interior forest to suburban areas [Power 1971].
Fall migration also begins early and is prolonged. In Ontario, some individuals begin migrating as early as late June [Keast 1980] and in Massachusetts the peak migratory period occurs from late August to early September [Veit and Petersen 1993]. However, some of these warblers have been reported on their breeding grounds well into the fall and winter [Kricher 1995 (BNA)]. It is assumed that the breeders from the southern part of the range are the first to return to their wintering grounds while the northern breeders arrive later [Lincoln 1935].
|
|
 |
Observations
This forest bark, trunk and twig-gleaning warbler was found in A, B and C sites. It was generally more abundant in B sites, except perhaps in NH. Black-and-white Warblers are mid-spring migrants, peaking in period 3 in all states. Many of the migrants are presumed to have passed north of the Connecticut R. valley by period 5, leaving a substantial breeding population throughout our whole study area.
The maximum transect total observed was 19 birds in period 3 at a MA B site on the upper Deerfield R. in 1996. |
|
|
|
|
