254 BULLETIN 203, UNITED STATES NATIONAL MUSEUM 



Guatemalan highlands, I had found Audubon's warblers flocking with 

 bluebirds. The myrtle warblers not only foraged about the bushes 

 which served the flycatchers as watch-towers; but the two kinds of 

 birds, so dissimilar in size and habits, changed their feeding grounds 

 together. While I sometimes found the warblers alone, I saw them 

 in company with the fork-tailed flycatchers too often for the associa- 

 tion to be looked upon as accidental. I could not discover that either 

 warbler or flycatcher derived any material advantage from the pres- 

 ence of the other. It seemed to be a case of pure socialibility. 



"Central American dates are: Guatemala — Motagua Valley, near 

 Los Amates, December 31, 1932; Sierra de Tecpan, March 16, 1933; 

 Finca Moca, January 20-26, 1935; Nebaj (Griscom), April 27; La 

 Primavera (Griscom), April 8. Honduras — Puerto Castilla, Jan- 

 uary 27, 1931 ; Tela (Peters) , March 17. Costa Rica — Vara Blanca, 

 December 13, 1937, to February 28, 1938; Guayabo (Ridgway and 

 Zeledon), March 18; Carrillo (Underwood), October 2; Guacimo 

 (Carriker), December 4; Las Caiias, Guanacaste, November 21, 1936; 

 El General, January 12, 1936 ; Buenos Aires de Osa, December 24-30, 

 1937." 



DISTRIBUTION 



Range. — North America. 



Breeding range. — The myrtle warbler breeds north to northern 

 Alaska (Kobuk River and timberline on the south slope of the Brooks 

 Range) ; northern Yukon (La Pierre House) ; northern Mackenzie 

 (Aklavik; Fort Anderson; MacTavish Bay, Bear Lake; Lake Hard- 

 isty, and Artillery Lake) ; northern Manitoba (Lac du Brochet, 

 Cochrane River, and Churchill) ; northern Ontario (Moose Factory) ; 

 southern Labrador (Grand Falls and Rigolet, possibly Nain and 

 Okkak) . East to eastern Labrador (Rigolet and Cartwright) ; New- 

 foundland (St. Anthony, Canada Bay, and St. John's) ; and Nova 

 Scotia (Cape Breton Island, Sable Island, Halifax, and Yarmouth). 

 South to southern Nova Scotia (Yarmouth) ; New Brunswick (Grand 

 Manan) ; southern Maine (Gouldsboro, Deer Isle, Bath, and Auburn) ; 

 New Hampshire (Concord) ; central and southern Massachusetts 

 (Marlboro, Webster, and Pelham) ; southwestern Vermont (Benning- 

 ton) ; northern New York (Falls Pond and Buffalo) ; rarely north- 

 eastern Pennsylvania (Pocono Lake) ; accidentally in northern Mary- 

 land (Havre de Grace) ; southern Ontario (London and Sarnia) ; 

 northern Michigan (Crawford County and Douglas Lake) ; northern 

 Wisconsin (Antigo, probably, Trout Lake, Namekagon Lake, and 

 Superior) ; central Minnesota (St. Cloud, Brainerd, and Bemidji) ; 

 southern Manitoba (Winnipeg and Aweme) ; central Saskatchewan 

 (Flotten Lake and Prince Albert) ; central Alberta (Flagstaff, Cam- 

 rose, Lobstick River, and Wipiti River) ; northern British Columbia 



