90 THE MIGRATIONS OF BIRDS 



As a feature of local migration movement there 

 may be noticed the interesting summer flights of 

 herons. In the southeastern United States the little 

 blue heron {Florida caeruled) is common near the 

 coasts, and nests in colonies, sometimes with or 

 near the snowy heron and the American egret. The 

 immature little blues (which are often pure white 

 except for more or less slaty wash on the tips of 

 the primaries, so that they may be mistaken for 

 egrets) wander regularly after they are grown, and, 

 strangely enough, at this season many of them pene- 

 trate to the north far beyond their breeding range. 

 At the end of July scattered birds begin to appear 

 along the Potomac, the Patuxent, and the Susque- 

 •hanna rivers, tributary to Chesapeake Bay, and in 

 many years the birds become common in August. 

 With them come snowy herons and egrets in casual 

 company, and all three travel north on occasion as 

 far as New England. In the Mississippi Valley they 

 are found regularly north to southeastern Kansas 

 and Illinois. In September most of these birds dis- 

 appear, and it is presumed that they return to the 

 south. 



Similar vagrant wanderings are recorded for 

 white herons in Europe and Asia, and apparently 

 hold true in the reef heron {Demigretta sacra) of 

 Australian coasts and a broad range among islands 

 in the South Pacific, which is recorded as a wanderer 

 at many points. 



