O INTRODUCTION 



acterized by a distinctly more boreal facies. This boreal 

 element is also found in the cold bogs and swamps of the 

 lower levels to the eastward. 



Placed as it is on the shore of the North Atlantic Ocean, 

 with the long arm of Cape Cod and the neighboring islands 

 reaching far out into the sea, an exceptional number of 

 sea and shore birds might confidently be expected; while 

 the mainland part of the district, lying adjacent to the 

 coast, naturally becomes an important migration route for 

 the land birds. The sea also acts as a barrier to limit the 

 eastward flight of wanderers from the West, South and 

 North. These facts, combined with the populous charac- 

 ter of the district, which probably contains a larger num- 

 ber of people interested in bird life, either as sportsmen, 

 students, or nature-lovers, than any district of equal size 

 in the country in proportion its population, naturally 

 result in a a very full and general knowledge of the native 

 bird life of the district, and the speedy detection of wan- 

 derers whenever they appear. 



Essex County, with its coastal waters, shares the charac- 

 teristics of the district as a whole in a marked degree, 

 though lacking any elevation of special note. The county 

 is of particular interest ornithologically for being the scene 

 of ]the discovery of the Ipswich Sparrow, a bird with 

 exceptionally interesting geographical distribution. The 

 county also forms apparently the northeastern limit of the 

 breeding range of several species, e. g., the Long-billed 

 Marsh Wren, Orchard Oriole, and Yellow-breasted Chat. 

 For a full treatment of the ornithological features of the 

 county, the reader should consult the work previously 

 cited. 



The List contains 390 species and subspecies. Of these 

 three are probably or certainly extinct; several more are 

 extirpated; three are believed to be hybrids; five or six 

 are known or believed to have been introduced; of about 



