Blackpoll Warbler Dendroica striata

Strictly a denizen of and fir forests, the Blackpoll Warbler is generally restricted to the higher-elevation boreal forests of Vermont, seldom occurring below 6IO m (2,000 ft) in southern portions of the state, though more widely distributed at lower elevations further north if suitable habi- tat is present. Wintering in south to Chile and Peru, more than 5,600 km (3,500 mil from its Vermont breeding grounds, it is one of the last of the wood warblers to return in the spring. Although migrants may begin appearing in the state during the second week in May, transients may be found well into June. habitat, but data are lacking on how much Blackpolls breed from the Alaskan mus­ habitat is necessary to sustain a local popu­ keg southeast to the Maritime provinces lation. Small pockets of occupied and un­ and western Massachusetts. Northernmost occupied, yet suitable, higher-elevation breeders make an annual round trip exceed­ breeding habitat are scattered throughout ing 16,093 km (IO,OOO mil in length. Radar Vermont, but further research is necessary studies have shown that many, if not most, to define the parameters limiting the Black­ Blackpolls fly nonstop across water from poll's occurrence. Morse (I979) speculated coastal New England to the coast of South that the Blackpoll Warbler might be ex­ America; their initial course would take cluded by its close relative, the Bay-breasted them into the South Atlantic Ocean if pre­ Warbler, from lower elevation coniferous vailing winds in southern latitudes did not forests in portions of their sympatric range. push them westward toward land (Nisbet That the Blackpoll is not more widespread 1970). in boreal forests in Vermont, despite the vir­ Blackpolls are among Vermont's largest tual absence of the Bay-breasted Warbler, in­ warblers, a fact that probably stands them dicates that other factors must restrict its in good stead in their immense overwater distribution. flight and on the nesting grounds, where Blackpolls build their bulky, well-concealed temperatures may dip below freezing well nest low in a , next to the trunk or, into the breeding season. The male, more occasionally, on the ground. Three to 5 strikingly marked-with his black cap (or creamy buff or greenish eggs, spotted and/or "poll") and streaked sides-than the somber wreathed with brown or lavender, are laid. female, sings his high-pitched song (inau­ Vermont egg dates (five nests) range from dible to some ears) from treetops throughout June 15 to June 26. Incubation and nestling his territory. During June the song is a char­ periods last approximately II days. Both acteristic feature of the stunted spruce-fir parents tend the young; age to indepen­ forests that crown Vermont's higher peaks. dence is unknown. Fledglings were reported Only two territory-mapping studies have by June 23 at Woodford (Ross, Field notes). been conducted in the Blackpoll's breeding The Blackpoll Warbler is one of Vermont's habitat in Vermont. Metcalf (I977) found most abundant fall migrants, mainly be­ 30 pairs per IOO ha (247 a) in coniferous cause most members of its Canadian popu­ forest near Wolcott. Blackpolls generally lation depart from the East Coast for South appear to be fairly abundant in suitable America. Departure dates of local breeders

306 Species Confirmed as Breeders in Vermont No. of priority blocks in which recorded TOTAL 33 (I8%) Possible breeding: 9 (27% of total) Probable breeding: IO (30% of total) Confirmed breeding: I4 (43% of total) D° o Physiographic regions in which recorded % 01 % of species' no. of region's total priority priority priority blocks blocks blocks DODO o Champlain Lowlands 2 6 6 Green Mountains I4 26 43 " .[!] DO ~ North Central 4 2I I2 o DO Northeast Highlands 8 50 24 20 '0 40 so , , I East Central 2 IO 6 4)' o · • Taconic Mountains I9 9 10 20 '0 ~ 1 1 I Eastern Foothills 0 0 0 o n' are, as a consequence, unknown, but most lacking. Lumbering activities in the North­ migrate in September; tardy Blackpolls east Kingdom may disturb some local popu­ may be present through the first week of lations, but it is unlikely that the species was October (exceptionally, to October 18). ever significantly affected by man's activities Although earlier authorities (Perkins and in Vermont, even during the height of agri­ Howe 1901; Allen 1909) considered the cultural clearing in the mid-1800s. species a common migrant, they were ap­ DOUGLAS P. KIBBE parently uncertain about the regularity with which it bred in the state. Currently the Blackpoll Warbler appears to be well dis­ tributed in the Green Mountains and North­ east Highlands, with more localized but significant numbers present in the North Central region and Taconic Mountains. Elsewhere the species appears rare or ab­ sent, probably because available habitat is

BlackpolI Warbler 307