492 LIFE HISTOEIES OF NORTH AMERICAN BIRDS. 



River, Alaska; and eggs from both of these localities are now in the United 

 States National Museum collection. 



The Rusty Blackbird has also been reported by several observers as breed- 

 ing commonly in Manitoba, but it is questionable if it nests there, or even in 

 Saskatchewan — certainly not on the open plains and on the ground, as stated. 

 All such records apply to Brewer's Blackbird, which was wrongly identified as 

 this species. 



The nest of the Rusty Blackbird is a substantial and bulky one. It is 

 usually placed in swampy places, near water, in small spruce saplings, from 3 to 

 9 feet from the ground, and occasionally in other low bushes. The base is prin- 

 cipally composed of sphagnum moss and earth, forming a firm, hard platform on 

 which the nest proper is built. This is thickly covered on the outside with 

 small tamarack and spruce twigs, mixed with a few blades of grass, pieces of 

 fern, and long, green moss, especially at the base, and the inner cup is thickly 

 and neatly lined with fine bright-green grass. 



A nest now before me, taken in Herkimer County, New York, on May 14, 

 1891, measures 7 inches in outer diameter by 5£ inches in depth; the inner cup 

 is 3£ inches wide by 2J inches deep. One of these nests will last for several 

 seasons, but a fresh one is usually built every year. These birds are very much 

 attached to their summer homes, returning to them from year to year, and 

 rarely more than two or three pairs nest in one locality; in fact, they are as often 

 found singly. The eggs number four or five to a set, and one is deposited each 

 day. Incubation lasts about two weeks, and the young are able to leave the 

 nest in about sixteen days. They are mouse colored at first, and are carefully 

 attended to by both parents, who are devoted to them. 



The fall migration from the more northern portions of their summer range 

 begins in the early part of September, and the species usually makes its appear- 

 ance in the Upper Mississippi Valley in the last half of October. 



The eggs of the Rusty Blackbird are mostly ovate in shape. The shell is 

 strong, finely granulated, and slightly glossy. The ground color is a light 

 bluish green, which fades somewhat with age; this is blotched and spotted 

 more or less profusely, and generally heaviest about the larger end of the egg, 

 with different shades of chocolate and chestnut brown and lighter shades of 

 ecru, drab, and pearl gray. The peculiar scrawls so often met with among the 

 eggs of our Blackbirds are rarely seen on these eggs, which are readily distin- 

 guishable from those of the other species. 



The average measurement of twenty-eight specimens in the United States 

 National Museum collection is 24.95 by 18.37 millimetres, or about 0.98 by 

 0.72 inch. The largest egg in the series measures 26.67 by 20.07 millimetres, 

 or 1.05 by 0.79 inches; the smallest, 23.11 by 17.78 millimetres, or 0.91 by 0.70 

 inch. 



Of the type specimens, No. 20266 (PI. 7, Fig. 14), from a set of four, 

 Bendire collection, was taken by Dr. C. Hart Merriam, near Big Moose Lake, 

 New York, June 15, 1883, and represents a coarsely blotched specimen; No. 

 25598 (PI. 7, Fig. 15), from a set of five eggs, Ralph collection, taken May 27, 



