NORTH AMERICAN BIRDS. SOS 



serted hole of a Sand Martin in a river bank. The nest is rudely constructed of 

 grass, moss, hair, wool, rabbits' fur, or any rubbish obtainable. The eggs usually 

 range from four to six in number and are of a pale, plain greenish-blue. A set of 

 four eggs collected riear Larne, Ireland, May 30, 1882, is in my collection. Their 

 sizes are .88x.60, .88x.59, .94x.60, .99x.61 inches. 



766. BLUEBIIM). Sialia sialis (Linn.) Geog. Dist. — Eastern United States, 

 north to Nova Scotia, Ontario, Manitoba, etc., west to the Rocky Mountains. Resi- 

 dent IH the Bermudas. 



In its several, forms the Bluebird is an inhabitant of the entire temperate North 

 America, and especially the eastern bird and also the western variety, occidentalis, 

 are familiar to all who study bird life in the regions in which they are to be found. 

 Dr. J. G. Cooper has aptly said that the Bluebird always bears the national colors, 

 red, white and blue, and that it Is one of the most strikingly peculiar of American 

 singing birds, and in its habits a model of civilized bird life. Its natural nesting 

 places are in the deserted excavations of Woodpeckers, hollows of trees, and even 

 in the crevices of rocky cliffs. With the progress of civilization the Bluebird has 

 taken advantage of modern surroundings, adopting the boxes that are put up for its 

 use, nesting also in every conceivable nook and corner in houses and barns. Very 

 frequently letter boxes upon fences are taken possession of. I found a Bluebird's 

 nest in the interior of a wheel of a railroad car during the strike a few years since, 

 and on another occasion, in Morrow county, Ohio, I discovered a brood of young Blue- 

 birds in a Cliff Swallow's nest under the eaves of an old barn. The normal color of 

 the eggs of the Bluebird is uniform pale blue, unspotted. They are four, five, and 

 sometimes six in number, and their average size is .84x.62. The eggs of this bird are 

 frequently very light bluish-white, and rarely pure white. All found in one nest are 

 of one tint; that is to say, a white egg is never found in a set with the blue ones. 



766o. AZTJBE BLTJEBIBD. Sialia sialis azurea (Swains.) Geog. Dist. — 

 Southern Arizona and Eastern Mexico. 



This bird has the same habits of S. sialis and the eggs are indistinguishable. 

 Breeds in Southern Arizona and southward. 



767. WESTEKM" BLUEBIRD. Sialia me^icaiti occidentalis SWains. Geog. 

 Dist. — Western United States, from the Rocky Mountains to the Pacific, south to 

 Southern Mexico. 



An inhabitant of Western United States north to "British Columbia. Its habits 

 are exactly similar to those of the Eastern Bluebird. It nests in holes and cavities of 

 decayed trees, between their trunks and the loose bark, making the nest of sticks, 

 grasses, straws, and almost any rubbish procura,ble. Mr. Walter E. Bryant states 

 that Dr. Cooper informs him that he has known a Bluebird to build in a Cliff Swal- 

 low's nest. The eggs of this species ^re four or five in number, uniform pale blue, 

 of a slightly deeper shade than those of- the preceding species, and average .81x.62 

 inches. 



767a. CHESTNUT-BACKED BLUEBIRD. Sialia mexicana bairdi Ridgw. 

 Geog. Dist. — Rocky Mountain district, south to Northern Mexico. 



The habits and characteristics of this subspecies are identical with those of S. 

 sialis. 



