6 MICHIGAN BIRD LIFE. 



in the boundary between Canadian and Transition. Other points similarly 

 determined would give, when connected, the actual boundary line. In the 

 same way theoretically the boundary between Carolinian and Transition 

 could be determined. Practically, however, the matter is far from simple. 

 It is not easy to decide exactly what species really belong to the Canadian 

 or the Carohnian and hence can be used as test species. Birds are less useful 

 than mammals or plants for this purpose, since they move so freely and 

 rapidly and are so hkely to wander or to be carried accidentally far outside 

 their proper habitat. And it often happens that a species which in one 

 part of the country, say the East, may be perfectly characteristic of a certain 

 faunal area will be a very unsafe index a few hundred miles farther west. 

 ^ Take for example the species which Dr. Merriam names as characteristic 

 of the Carolinian. Among these the sassafras, the fox squirrel and the gnat- 

 catcher are found throughout the greater part of the Lower Peninsula, while 

 the summer tanager does not occur at all — not even in the southernmost 

 counties. On the other hand the porcupine and varying hare, both Canadian 

 forms, were found, until very recently at least, in practically every county in 

 the state, not infrequently side by side with the opossum and the Cardinal. 

 The Carolina Wren, Mockingbird, Yellow-breasted Chat and Tufted Tit 

 occur sparingly, perhaps accidentally, over a wide area in the Lower Penin- 

 sula, but seem to be nowhere common. 



In the present state of our knowledge, or rather of our ignorance, we hesitate 

 to accept Merriam's faunal map, yet are not prepared to offer a substitute. 

 The indications, however*, all point toward a decided lessening of the Michigan 

 areas assigned by him to the Canadian and Carolinian, with a corresponding 

 increase in the size of the AUeghanian or Transition. 



BIRD LIFE IN MICHIGAN. 



In view of the facts just set forth it seems hardly wise to attempt an 

 enumeration of the bird species found in each of the faunal areas represented 

 in the state. Instead it may be worth while to take a rapid survey of some 

 of the different regions of the state with brief lists of the commoner or more 

 characteristic species found in each. It must be distinctly understood that 

 the mere naming of a species as an inhabitant of any one region does not by 

 any means imply that it may not occur elsewhere frequently or regularly. 



It should be noted also that when species are named as common residents 

 of any region it is meant as a rule that they are found there during the nesting 

 season, that it is in a sense their home. In this connection reference should 

 be made to a later page in which the subject of migration is briefly discussed. 



In talcing up the matter of bird distribution in Michigan, it will be con- 

 venient to consider the bird life of five different regions, namely : 



1. The Prairie Region of the South. 



2. The Great Marsh Regions of the southeastern border. 



3. The Pine Forest Region. 



4. The Plains Region, or "Jack Pine Plains." 



5. The Hardwood Forest Region. 



The Prairie Region of southern Michigan is really little more than an 

 extension northward of the prairies of the adjoining states of Indiana and 

 lUinois. Probably it was always devoid of pine forests, at least that has 

 been its condition for the last few centuries, and it is now but lightly forested 

 at best, and with many large stretches of nearly level land. Characteristic 



