450 BULLETIN 2 03, UNITED STATES NATIONAL MUSEUM 



DENDROICA PALMARUM HYPOCHRYSEA Ridgway 



YELLOW PALM WARBLER 



Contributed by Winsor Mareett Tyler 



Plate 56 



HABITS 



We may suppose that tlie yellow palm warbler has been moving up 

 and down the Atlantic coast on its migrations to and from Canada 

 for many years, perhaps since the glacier retreated and opened the 

 road to its breeding-ground some 15,000 or 20,000 years ago, but it is 

 only recently, a little more than two generations ago, that ornitholo- 

 gists have recognized that the bird was distinct from the palm war- 

 bler which breeds and migrates farther toward the west. Robert Ridg- 

 way (1876) called attention to a marked difference in the plumage 

 of the migrant palm warblers taken in the Mississippi Valley and 

 those from New England and southw^ard. He pointed out that the 

 latter birds were uniformly bright yellow below, streaked, especially 

 on the sides, with chestnut, and that the back was "greenish-olive," 

 whereas the western birds were yellowish-wliite beneath, only tinged 

 with yellow, except on the throat and crissum where they were clear 

 yellow, while the entire breast was streaked with brown, and the back 

 was "dull olive-brown." The eastern birds were also slightly larger 

 in all dimensions. 



The eastern form was accepted as a subspecies of the palm warbler 

 and appears in the first edition of the A. O. U. Check-List (1886) as 

 hypochrysea^ golden beneath. Subsequently it was found that the 

 breeding ranges of the tw^o races lie chiefly in Canada, roughly to the 

 east and west respectively of the longitude of the southern tip of 

 Hudson Bay. 



Of the older writers, Wilson and Nuttall, who studied chiefly the 

 birds of the northeastern United States, apparently met only the yel- 

 low palm warbler, and Audubon definitely describes it, but his re- 

 marks on the birds he saw commonly in Florida throughout the 

 winter without much doubt apply to the western race. 



Spring. — The yellow palm warbler, in spite of its small size and 

 fragile appearance, is evidently a hardy bird. It pushes northward 

 into New England early in April when winter is not far behind us, 

 at a season of uncertain weather, with perhaps even snow, and before 

 many of the leaves have expanded fully. The bird passes through the 

 Transition Zone a full month before the horde of north-bound migrant 

 warblers which brighten the treetops in mid-May ; it comes even earlier 

 than the robust myrtle warbler which has wintered not far away; 

 and before the black and white creeper which feeds from the bark 



