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fields, another the undergrowth, and a third the marshes? 

 What is the exact nature of the environment in which each 

 lives, and wherein are these environments dissimilar? What 

 are the adaptations of each species to its peculiar habitat, 

 and how has each become dependent upon it? Questions such 

 as these demand an intimate knowledge, not only of every 

 phase of the life history of each bird, but also of every condi- 

 tion that might be imposed by its surroundings. The nearer 

 completeness can be approached in this knowledge, the more 

 nearly perfect will be the understanding of the relations 

 existing and the reasons for these relations. Investigations 

 in this subject must of necessity become intensive rather than 

 extensive. The known facts are yet too meager to admit of 

 broad generahties or the comprehension of such diverse rela- 

 tions as exist in even a normally circumscribed habitat. For 

 this reason, one environment has been selected for study, and 

 efforts have been concentrated upon a single species. 



The cat-tail marsh, which is here considered, is as peculiar 

 and distinctive as any environment available for study. 

 Great expanses of sedge, rush, and cat-tail conceal an assem- 

 blage of birds which are as interesting as they are little known^ 

 birds that are little known because of the difficulties in their 

 study, that are seldom seen because of their secretive habits, 

 yet withal, birds that are as unique in their adaptations, as 

 varied in their structure and habits, as any other similar group. 

 There are the Rails, the Coot, and the GaUinule constituting 

 an ecological unit in themselves, the Marsh Wren, Swamp 

 Sparrow, and Red-winged Blackbird another, the Least and 

 American Bitterns, and the Pied-billed Grebe still others. All 

 are strictly marsh birds which seem to find their optimum 

 environment in the cat-tail marsh. With some of these 

 birds, adaptation to a marsh fife is very evident, but with 

 others, it is quite obscure. The long legs of the Virginia Rail 

 for wading, the long toes for grasping the floating debris and 

 distributing the weight, the long bill for probing, the color, 

 the compressed shape — like that of a flea — for slipping through 

 the dense vegetation, are decided speciafizations for a life in 

 this peculiar environment. The Swamp Sparrow and the 

 Redwing, on the other hand, show no striking modifications, 

 4 



