14 SIEUR DE MONTS NATIONAL MONUMENT 



Canadian and Alleghanian — drawing from each many species 

 which scarcely surpass this limit north or south; while 

 some even of the Hudsonian birds from remote sub-arctic 

 regions frequent its rocky shores and mountain tops. 



Technically the Island of Mount Desert comes within 

 the boundaries of the Canadian faunal area, but lying so 

 near its southern limit, many of the typical Alleghanian 

 species are frequently found upon it. For, as Knight says, 

 in his excellent work on the Birds of Maine,* "The change 

 from one area to another is not at all abrupt; but instead, as 

 we near their common boundary we find species common to 

 both occurring on the same grounds." For example, the 

 northern-ranging Bicknell's Thrush and the Canadian sub- 

 species of the Hudsonian Chicadee, as well as such southern 

 species as the White-eyed Vireo, Wood Thrush, and Blue- 

 gray Gnatcatcher have been observed. 



For while the Canadian zone is distinguished by the 

 high development of its coniferous forests, and while these 

 are typical of this Island, imparting to it their distinctive 

 Canadian quality, its position, jutting far out to sea, so 

 tempers the climate in relation to the neighboring interior 

 as to make it the frequent resort of many birds which 

 would not otherwise be tempted so far North. 



SITUATION ON A GREAT MIGRATORY ROUTE 



It is well-known that the migration routes of most 

 birds follow the lines of important natural features, such as 

 great mountain chains, river valleys, and especially the 

 sea coast. The border of the Atlantic Ocean, constitutes 

 accordingly, the principal highway for the majority of all the 

 eastern land species, while for most aquatic birds this route 

 is almost exclusively the main thoroughfare. Along these 

 migratory routes, again, unusual landmarks, and particularly 

 prominent elevations, serve as guides an4 rallying points for 

 the travellers on their long journeys. 



*"The Birds of Maine" by Ora Willis Knight, Bangor, Maine, 1908. 



