DIRECTORY TO BIRDS OF EASTERN NORTH AMERICA. 205 



Mountain range as an offshoot from 1, and followed the re- 

 treating ice of the glacial period up the coast where it would 

 have been barred from mingling with the parent stock to the 

 westward by the high and cold mountain range. Shows its 

 instability not only in its variability but by an inclination to 

 return to its ancestral color characters when placed under 

 environment similar to that in which 1 lives, as in some por- 

 tions of southern N. E. [Note :- For theory concerning mi- 

 gration of birds see a report of a lecture given by C. J. May- 

 nard before the Boston Scientific Society in the "Boston Com- 

 monwealth" Nov. 30, 1895, and a longer account in "Contri- 

 butions to Science" Yol. Ill, No. 1, March, 1896; also a con- 

 tinuation of the same in No. 2 wherein the relationship of 

 these Grackles is discussed at greater length. ] 



i. Boat-tails. Megraqiiiscalus. 



Differ from h in being larger, with longer, more strongly 

 graduated tails ; males nearly uniform iridescent black and 

 the females brownish. Nests in marshy places. 



1. BOAT-TAILED CRACKLE, M. major. 16.00; iri- 

 descence of head, neck and upper breast bluish-violet; blu- 

 ish-green elsewhere, fig. 269. Female reddish-brown, dark- 

 est above. Young, both sexes similar to female. South At- 

 lantic and Gulf Coasts of U. S. from Ya. to Texas. Song, a 

 series of sharp, loud notes given rapidly, as a kind of chat- 

 ter, this is sometimes preceded by a single, more mellow, 

 note; also makes a shuffling sound which may be produced 

 by the wings, and a sharp croak when annoyed. The sexes 

 do not, as a rule, associate unless breeding. Occur in open, 

 marshy places. Yery abundant. 



j. Parasitical Blackbirds. Molotlirus. 



Small blackbirds nearly uniform in color ; bill, short, con- 

 ical ; wings, rather long, tail not long and slightly rounded. 

 Our species is polygamous, and deposits its eggs in the nests 

 of other birds. 



