128 TIIR WILSON BULLETON No. G4. 



This species at the Point is a common spring and fall migrant. 

 On the Michigan side, in our locality, it is a common fall mi- 

 grant but very rare in spring. Up to 1907, indeed, it. had nev- 

 er been taken in this vicinity. However, May 19 of that year 

 one was taken by Tavemer at Pearl Beach, near the St. Clair 

 Flats, and the succeeding year another May 16 at Detroit. 



White-crowned Sparrow. 



W r e have invariaby found the White-crowned Sparrow a com- 

 mon spring and fall migrant at the Point, but of late years, 

 since 1904, it has been either rare or absent in our notes along 

 the Michigan side of the line. It was more common this last 

 spring of 1908, but in nothing like the numbers we have been 

 accustomed to see in the past. 



These are rather peculiar cases and seem to indicate that the 

 source of the Point Pelee avifauna is distinct from that of the 

 adjoining Michigan stations. The water chain joining lakes 

 Huron and Erie seems to form a sharp dividing line between 

 the two areas. This in the fall migrations is easily explained 

 by the plausible theory that the two sections are traversed by 

 migrational streams from opposite sides of Lake Huron. The 

 dissimilarity of the spring migrants and summer residents can 

 be explained in no such obivious manner. According to more 

 or less currently accepted theories of Glacial drainage migra- 

 tion routes, it may be that Southeastern Michigan receives its 

 migrant life by way of the old Maumee glacial drainage chan- 

 nels while Pelee is supplied by other routes ; perhaps continu- 

 ing along the Ohio river, past the mouth of the Wabash and up 

 the Sicoto to the head waters of the Sandusky, then down that 

 stream to Lake Erie and so across to Point Pelee. This is as 

 yet purely conjectural through lack of further data on the sub- 

 ject. It suggests, however, an important line of work and one 

 that is well worth following up. 



And now the end of the work before us has come. That 

 which was begun as a short informal list has, thanks to the gen- 

 erous editor of the Bulletin and the forebearance of the reader, 

 lengthened out far beyond the original intentions of the writers 

 as the data increased and the importance of the locality seemed 

 to demand. No one is better aware of the manifold shortcom- 



