V0l ; 9 o5 XI1 ] WoOD & Frothingham, Birds of Au Sable Valley. 45 



see this species. I found hunters who reported that they had 

 taken them in fall or winter. 



As we went down the river the descent was very gradual for the 

 first two hundred miles, about 200 feet for every 100 miles, until 

 we reached the rapids in Alcona County where the fall was 269 

 feet per hundred miles, and perhaps one half of this fall occurs in 

 a distance of five miles. 1 



Passing from Alcona into Iosco County, the descent was quite 

 noticeable and the river much swifter. In the lower fifty miles 

 the river was slower and full of islands ; the channel also was 

 wide and marshy, with submerged swamps full of dead trees. 

 Here we saw the willow along the river's margin. Below the 

 rapids we saw for the first time extensive meadows, and in them 

 were the Meadowlark and Red-winged Blackbirds. 



In the region of highest altitude, or from Grayling, Oscoda 

 County, 1250 feet, down to Flat Rock, Alcona County, about 900 

 feet, we find some northern forms such as White-throated Sparrow, 

 Junco, Red-breasted Nuthatch, Winter Wren, Hermit Thrush, 

 Olive-sided Flycatcher, Arctic Three-toed Woodpecker, and Kirt- 

 land's Warbler, all Canadian fauna. Below 900 feet (to the lake, 

 581 feet) we found such forms as the Meadowlark, Purple Martin, 

 Yellow-throated Flycatchers, Mourning Dove, and the Red-winged 

 Blackbird. — N. A. W. 



Annotated List. 



1. Colymbus auritus. Horned Grebe. — Alcona Co., Sept. 19, one seen 

 in a bajou. 



2. Podilymbus podiceps. Pied-billed Grebe. — Crawford Co., Sept. 

 12, very few seen. Oscoda Co., Sept. 15, occasionally seen. Alcona Co., 

 Sept. 20, one seen. Iosco Co., Sept. 21, quite rare. 



3. Merganser americanus. American Merganser. — Crawford Co., 

 Sept. 5, two seen. Oscoda Co., Sept. 18, a pair seen at mouth of North 

 Branch. Alcona Co., Sept. 19, a female seen on the river. These were 

 perhaps migrants. 



4. Lophodytes cucullatus. Hooded Merganser. — Crawford Co., 

 June 30. Several females with young were seen on South Branch. 



1 These estimates of altitude were made from data kindly furnished by Mr. 

 Frank Leverett. 



