EASTERN DOWITCHER 107 



because no distinctly different breeding ranges for the two forms 

 have been established, and typical (so-called) eastern birds have never 

 been found breeding anywhere. What few breeding birds have 

 come from Alaska and northern Mackenzie all seem to be scolopa- 

 oeus, but griseus may still be found breeding there when we have 

 larger series. I have had considerable correspondence with Prof. 

 William Rowan about the breeding dowitchers of Alberta, including 

 interchange of specimens. He seems to think that the Alberta 

 birds are constantly distinct from either griseus or scolopaceus and 

 perhaps worthy of a name. It seems to me that they are strictly 

 intermediate and should not be named. In a letter recently re- 

 ceived from P. A. Taverner he seems inclined to recognize the 

 Alberta bird as a " short-billed bird resembling the eastern most, 

 but intermediate, and with spotting characters different from either." 



On migrations, and in winter, both forms are found entirely 

 across the continent. The best that can be said is that griseus is 

 more common on the Atlantic and scolopaceus is more common on 

 the Pacific coast. Dr. Louis B. Bishop, with whom I have dis- 

 cussed this question, is inclined to call one a mutant of the other; 

 he has some 200 dowitchers in his collection, from all parts of the 

 country, those from the Atlantic and Pacific coasts being about 

 equally divided and the two forms being about equally represented. 

 In analyzing his series, taking into account length of bill, length of 

 wing and brightness of color, he finds that: of griseus, 86 per cent 

 are from the Atlantic coast, 2 per cent from the interior, and 12 

 per cent from the Pacific coast; and of scolopaceus, 14 per cent are 

 from the Atlantic coast, 30 per cent from the interior, and 56 per 

 cent from the Pacific coast. While collecting near Pasadena, Cali- 

 fornia, on April 25, 1923, he shot into a large flock of dowitchers 

 and picked up nine birds, all but one of which were typical griseus, 

 in bill, wing, and color. 



Spring. — The last of the dowitchers which winter in Florida, or 

 migrate through there, leave for the north during May, though a 

 general northward movement has been going on during April. The 

 earliest birds sometimes reach Massachusetts by May 1, but usually 

 the main flight comes along about May 20 and lasts for about ten days. 

 Audubon (1840) observed large numbers of this species flying east- 

 ward along the coasts of Louisiana and Texas during April. And 

 Arthur T. Wayne (1910) says that "these birds migrate to their 

 breeding grounds in the far north between May 1 and 15, and when 

 the tide is low in the afternoon and a light southerly wind prevails, 

 flock after flock can be seen migrating in a northwesterly direction. 

 I have yet to see these birds migrate along the coast line in the 

 spring." This would seem to indicate an overland route from South 



