THE BUKROWmG OWL. 399 



year to year; in such a case it is cleaned out and repaired, if necessary. In 

 different localities their choice in the selection of nesting sites varies somewhat- 

 At Fort Lapwai, Idaho, they generally selected a burrow on a hillside with 

 a southerly exposure, while at Walla Walla their nests were always foimd 

 in burrows on level ground. At Camp Harney, Oregon, where the Buitow- 

 ing Owls were not very common, one under a large basaltic bowlder seemed 

 to be a favorite site with them, and here they encroached upon the timber 

 in the foothills of the Blue Mountains. At Fort Custer, Montana, I found 

 them mostly on level ground, generally bottom lands, and always at the out- 

 skirts of a prairie dog village. On the Pacific coast the burrows of the ground 

 squirrels are more often used for nesting sites, and occasionally those of badgers, 

 which are quite common in some sections. If one of the former is selected, it 

 has first to be considerably enlarged, and which requires a good deal of 

 patient labor on the part of the Owls to accomplish. While stationed at Fort 

 Lapwai I had an opportunity to see an Owl at work enlarging and cleaning 

 out a burrow. The loosened dirt was thrown oiit backward with vigorous 

 kicks of the feet, the bird backing gradually toward the entrance and moving 

 the dirt outward in this manner as it advanced. These burrows vary greatly 

 in length and depth, and are rarely less than 5 feet in length and frequently 

 10 feet and over. If on level ground they usually enter diagonally downward 

 for 2 or 3 feet, sometimes nearly perpendicularly for that distance, when the bur- 

 row turns abruptly, the nesting chamber being always placed above the lowest 

 part of the burrow. If in a hillside it will frequently run straight in for a few 

 feet, and then make a sharp turn direct to the nesting chamber. At other 

 times the burrow follows the cm-ves of a horseshoe, and I have more than 

 once found the eggs in such a burrow lying within 2 feet of the entrance and 

 close to the surface of the hill on a trifle higher level; where, had it been 

 known they could have been reached with little trouble. These burrows are 

 generally about 5 inches in diameter, and the nesting chamber is usually 

 from 1 foot to 18 inches wide. After the burrow is suitably enlarged, espe- 

 cially at the end, dry horse and cow dung is brought to the entrance of it, where 

 it is broken up in small pieces, can-ied in and spread out in the nesting cham- 

 ber which is usually lined with this material to a thickness of 1 or 2 inches, and 

 I have never found any other material in the nest. In California, however, 

 they are said to line them occasionally with dry grasses, Aveed stalks, feathers, 

 and similar materials. On one thing most observers agree, namely, that their 

 burrows invariably swarm with fleas. 



In southern California the Burrowing Owl commences laying about the 

 beginning of April; in Oregon, Washington, and Idaho, rarely before the 

 15th of the month, and usually about the latter part of it; in' Kansas and 

 northern Texas it begins about the same time; in Utah, fresh eggs have 

 been found as late as June 15, and at Fort Collins, Coloi-ado, on July 1. 



Although incubation does not appear to begin until the clutch is nearly 

 completed, I always found one of the parents at home, even if there was but 

 a single egg in the nest. The old bird is courageous in the defense of its 



