392 BULLETIN 2 3, UNITED STATES NATIONAL MUSEUM 



fall migrations, notes that at Athens, Ga., and in the Piedmont region 

 in general the blackpoU is an abundant spring migrant but in the fall 

 is exceedingly scarce. Likewise at Asheville in the mountains of 

 North Carolina, it is an abundant spring migrant and completely- 

 absent in autumn. On the coast it is common only in fall. ISIr. Bur- 

 leigh states : "It apparently, in the west to east migration in the fall 

 from its breeding grounds in the far northwest, is moved by some im- 

 pulse to reach the coast as soon as possible, and as a result it is at best 

 merely a straggler over much of the area it occupies in the spring 

 migration." 



Swales and Taverner (1907) have noted that the black-polled 

 warbler, though one of the most abundant fall migrants in south- 

 eastern Michigan, is conspicuously absent in the region of Detroit, 

 Wayne County, in spring. No explanation is offered to account for 

 this peculiar situation in that section of its migration journey. 



The fall migration of the blackpolls as it occurs in the "VVliite Moun- 

 tains of New Hampshire is of interest. These birds breed commonly 

 in the upper Canadian Zone mainly above 3,000 feet on southern ex- 

 posures and down to 2,000 feet on the northern slopes. During Sep- 

 tember they swarm in migration over the low country of the southern 

 part of the State and beyond, but in the valley bottoms among the 

 mountains they are rare. Here they migrate mainly at the upper 

 levels and along the mountain tops. The tendency to migrate at the 

 higher elevations along mountain ranges has been observed in other 

 sections of the migration course. On September 15, 1900, Glover M. 

 Allen (1903) observed a great flight of black-polled and myrtle 

 warblers starting at 4 : 30 a. m. and continuing for 2 hours in the 

 White Mountains. Several hundred birds passed, of which three- 

 fourths were blackpolls. These warblers came flying in from the 

 south, high in the air, making straight for Carter notch, a great rift 

 in the mountain with a valley opening out toward the north and 

 another to the south. "It seemed," Dr. Allen writes, "as if the black- 

 poll warblers from all of the forests immediately to the south were 

 moving north in a concerted manner to pass through the notch and 

 off beyond. Possibly they were heading for the Ammonoosuc Valley 

 to continue thence down the Connecticut; this would be a natural 

 course, and one cannot suppose that their northward flight at this 

 season could have been more than some such local movement." 



Norman Criddle (1922) has taken migration records of the black- 

 poll over a period of 21 years at Aweme, Manitoba, Canada, where he 

 flnds the average date of appearance in spring to be May 14, with his 

 earliest date on May 9, 1902. In autumn the average date of last birds 

 seen was September 9, and the latest record was one observed on 

 September 15, 1912. 



