128 :north ameeican warblees. 



gheny Mountains and eastward do not come north by way of Texas. 

 This fact, coupled with the absence of the species from the Gulf coast, 

 seems to show that the return from the South is made b}^ a flight across 

 the Gulf of Mexico. This trip requires a sustained flight of at least 

 TOO miles, but there seems to be no other assumption to exi3lain the 

 observed facts. Records of average dates of arrival farther north are: 

 Washington, May 9; Englewood, N. J., May 13; Beaver, Pa., May 

 15; East Hartford, Conn., Ma}^ 13; eastern Massachusetts and south- 

 ern New Hampshire, Ma}^ 17; southern New Brunswick, May 26. In 

 southern New England the species often appears by Ma}^ 10. A Wil- 

 son warbler w^as taken at Godbout, Quebec, June 3, 188-1, and one on 

 the Hamilton River, Quebec, May 31. West of the Alleghenies the 

 first arrivals are noted on the average at Waterloo, Ind., May 15; 

 southern Michigan, May 17; Ottawa, May 20; Chicago, May 14; 

 Lanesboro, Minn., May 8; Elk River, Minn., Mav 14; Aweme, Mani- 

 toba, May 15; and Fort Chippew^^an, Athabasca, May 26. 



Fall jnigratkm.—TliQ Wilson warbler breeds so far north that the 

 earliest returning migrants do not appear before August in the United 

 States. They have been noted at Lanesboro, Minn., August 23, 1887; 

 Grinnell, Iowa, September 3, 1887; Chicago, August 16, 1896; Beaver, 

 Pa., September 7, 1889; Englewood, N. J., August 15, 1886; and 

 Washington, August 28, 1887. Some records of the last seen are: 

 Aweme, Manitoba, September 10, 1901; Lanesboro, Minn., September 

 27, 1891; Grinnell, Iowa, September 25, 1888; Ottawa, September 29, 

 1890; Pictou, Nova Scotia, August 24, 1894; St. John, New Bruns- 

 wick, September 17, 1896; Renovo, Pa., September 30, 1895; Ger- 

 mantown. Pa., October 15, 1889. The time of migration south of the 

 United States can not be traced, because the records of the eastern 

 and the western forms can not be separated. 



685a. Wilsonia pusilla pileolata (Pall. ). Pileolated warbler. 



Breeding range. — By this subspecies in the present connection is 

 meant the form that occurs throughout the Rocky Mountains and in 

 the Great Basin. It breeds north into Alaska and as far south as 

 western Texas, and possibly the higher mountains of Arizona and 

 Mexico. It ranges casually to Minnesota and western Missouri. In 

 Colorado it breedvS commonly at timber line, ranging from 12,000 feet 

 down to 6,000 feet. 



Winter range.- — The abundance of the pileolated warbler in winter 

 in Mexico is attested b}" the fact that the occurrence of the bird has 

 ])een noted by the parties of the Biological Survey more often than 

 that of an}^ three other species together. It is common from Nuevo 

 Leon southward, and in the western part of Mexico on the high- 

 lands at least to Durango. It is there a mountain lover, common from 

 4,000 to 9,500 feet and ranging to 12,000 feet on the north slope of 



