SAND DUNES AND SALT MARSHES 



a large territory, the swamp sparrow limits 

 itself to the almost uniform environment of 

 swamps, and has therefore never developed 

 any races or sub-species. 



Another bird which is showing great devel- 

 opmental or evolutionary possibilities is the 

 grackle, often known as crow-blackbird. This 

 bird, instead of shunning man, has been bright 

 enough to appreciate the fact that it is safest 

 from persecution when in most intimate rela- 

 tions with him. It has come into his towns 

 and cities, and it does not hesitate to build 

 its nests on his houses. In Boston, although 

 there had been a few previous records, it was 

 not until 1900 that this bird began to breed 

 regularly in the Public Garden, and the num- 

 bers increased so that thirty-two nests were 

 counted there by Mr. H. W. Wright in 1906. 

 In 1907 they first began to build nests in the 

 vines on my Ipswich house, and two pairs have 

 nested there every summer since, when I per- 

 mitted. In the matter of food they are not 

 particular, or rather their appetite is a catho- 

 lic one, and they can adapt themselves to cir- 

 cumstances. They are able to pick eggs out 

 of a robin's nest and peas from pods in the 

 garden, and they undoubtedly serve a useful 



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