78 Bulletin of the 



p. m. but few hawks were seen flying, though large numbers were perched in 

 tree-tops. Many of these were identified, and all proved to be sparrow hawks. 

 During the forenoon flight many of the hawks flew over the lake at a short 

 distance from shore, but almost none were seen farther out than a distance 

 of one hundred or two hundred yards ; and in fact many were noticed coming 

 from over the water as though returning to the land after venturing a short 

 distance from it. 



It seems to me quite probable that many of these hawks may have started 

 from points inland, and at considerable distances from the lake shore, but thit 

 in their flight they were influenced by the direction of the northeast wind and 

 thus reached the lake shore, which they followed southward, so that there 

 resulted a concentrated stream of hawks, including individuals, that under 

 other circumstances might have been distributed over a strip of territory many 

 miles in width. 



The general circumstances attending this hawk movement were similar to 

 those described by Trowbridge^ as accompanying hawk flights studied by him 

 on the shore of Long Island Sound, and they seem to quite satisfactorily 

 accord with his assumption that the d'rection of the wind is a very important 

 factor in the initiation and the determination of the direction of such extensive 

 movements. In the particular instance described above, the temperature 

 changes were comparatively slight. 



University of Illinois, November i, 1904. 



BIRDS OF THE BEAVER ISLANDS, MICHIGAN. 



WALTER B. B.XRROWS, F. A. 0. U. 



(Concluded from Page 66.) 



[Red-breasted Merganser. Merganser serrator. Several small squads and 

 one considerable flock of ducks were seen from the fish tugs at various times 

 in going and coming amojig the islands, but no specimen was taken and while 

 I have no doubt the birds belonged to this species, I do not care to include 

 it in the list without an actual specimen. The species, however, might 

 fairly be included, since Chas. L. Cass took a nest of this species in 1807 on 

 Hat Island, one of the Beavers, and the previous year he saw several broods 

 of young about that island. On Font Lake, Great Beaver Island, I saw 

 three half-grown ducks which certainly w^ere not mergansers. I suppo.sed 

 them to be Lesser Blue-bills. Ayrhya afUnis, but ?s no specimen was obtained, 

 I am not positive.] 



5. (194). Great Blue Heron, Ardea herodias. Seen frequently at vari 

 ous places. A "rookery" of some size is said to exist in the interior of 

 Hog Island, but I did not visit it. 



6. (263). Spotted Sandpiper; Tip-up. Acfitis macularia. A pair to 

 every mile or two of beach, but by no means abundant. 



^The Relation of Wind to Bird Migration, C- C Trowbridge, American Nat- 

 uralist, Sept.. 1900, pp. 735-753. 



