96 THE AMERICAN MUSEUM JOURNAL 



IVintcr Residents leaving for the North. 



Junco. Brown Creeper. 



Tree Sparrow. Red-breasted Nuthatch. 



Winter Wren. Golden-crowned Kinglet. 



Migrants arriving from the South. 



April I to 10. 



Pied-billed Grebe. Field Sparrow. 



Great Blue Heron. Chipping Sparrow. 



Black-crowned Night Heron. Tree Swallow. 



Osprey. Myrtle Warbler. 



Vesper Sparrow. American Pipit. 



Savanna Sparrow. Hermit Thrush. 



April 10 to 20. 



American Bittern. Barn Swallow. 



Green Heron. Yellow Pah« Warbler. 



Clapper Rail. Pine Warbler. 



Yellow-bellied Sapsucker. Louisiana Water-Thrush. 

 Ruby-crowned Kinglet. 

 April 20 to 30. 



Spotted Sandpiper. Purple Martin. 



Semipalmated Sandpiper. Cliff Swallow. 



Whip-poor-will. Bank Swallow. 



Chimney Swift. Rough-winged Swallow. 



Least Flycatcher. Black and White Warbler. 



Towhee. Black-throated Green Warbler. 



Blue-headed Vireo. Brown Thrasher. 



May Bird-Life. — As the season advances, marked changes in 

 temperature are less likely to occur, and the migration becomes regu- 

 lar and continuous. In February and March there may be two weeks 

 or more variation in the times of arrival of the same species in differ- 

 ent years ; in May we expect to find a given species within a day or 

 two of a certain date. We shall, nevertheless, find the force of the 

 migratory current still closely dependent on the weather, and 

 under the encouragement of a high temperature we may be visited 

 by "bird waves," flooding the woods with migrants. Birds are 

 then doubtless more abundant than at any other season. As many 

 as ten species may be noted as arriving on the same day, and sixty 

 or seventy species may be observed within a few hours. 



After May 15, birds begin to decrease in number, the Tran- 

 sient Visitants passing farther north, and by June 5 we have only 

 Permanent Residents and Summer Residents. 



BIRDS OF THE MONTH. 



Permanent Residents, see /'c^'c <V5. 

 Summer Residents, see f^age 86. 



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