398 LIFE HISTORIES OF NOKTH AMERICAN BIRDS. 



locating their prey or darting down noiselessly and swiftly, and grasping it with 

 their talons without arresting their flight an instant. The actual amount of food 

 a pair of these birds require to bring up their numerous family, generally aver- 

 aging eight or nine, is something enormous. Each Owl will eat fully its own 

 weight in twenty-four hours, if it can get it. 



I have, at different times, kept some of. these birds in confinement for a 

 week or more and fed them on Townsend's ground squirrels, an animal weigh- 

 ing more than this Owl. These were caught alive, and absolutely uninjured, 

 in wire traps baited with carrots, and turned loose in the room where the 

 Owls were kept; first, to see if they could actually kill rodents of this size, 

 and, second, to find out how much they would eat in a day. To test both, I 

 fed a pair of these Owls four live full-grown Townsend's ground squirrels in 

 one day, besides the carcasses of five small birds which had been skinned, 

 and was astonished at the ease and celerity with which these rodents 

 were killed and the small amount of resistance they made. I watched the 

 proceedings through a small hole in the door. As soon as a squirrel was 

 turned loose in the room with the Owls, one of them would pounce on 

 it, and, fastening its sharp talons firmly in the back of the squirrel, spread 

 its wings somewhat, and with a few vigorous and well-directed blows of its 

 beak break the vertebrae of the neck, and before it was fairly dead it com- 

 menced eating the head. This was always eaten first and is the favorite 

 part. Next morning there was but little left of squirrels or birds, and the 

 two Owls had certainly eaten considerably more than their own weight in 

 the twenty-four hours. It actually kept one busy to supply them with the 

 necessary food they would consume, which gives a fair idea of how much 

 a family of half-grown young must require. As nearly all the food used by 

 them consists of noxious vermin, it readily appears what an immensely ben- 

 eficial bird the Burrowing Owl is, considered from an economic point of view, 

 and deserving of the fullest protection. 



They appear to be mated when they make their first appearance in the 

 early spring, and I believe remain paired through life. At this season, where 

 they are abundant, and they are generally found in little colonies of several 

 pairs at least, their peculiar love note can be heard on all sides about sundown; 

 it reminds me more of the call of the European Cuckoo (Cuculus canorus) than 

 anything else, a mellow sonorous and far-reaching "coo-c-o-o," the last syllables 

 somewhat drawn out, and this concert is kept up for an hour or more. These 

 notes are only uttered when the bird is at rest, sitting on the little hillock 

 surrounding its burrow. While flying about, a chattering sort of note is used, 

 and when alarmed a short shrill "tzip-tzip." When wounded and enraged 

 it utters a shrill scream and snaps its mandibles rapidly together, making a 

 sort of rattling noise, throws itself on its back, ruffles its feathers, and strikes 

 out vigorously with its talons, and with which it can inflict quite a severe wound. 



Preparations for nidification begin in the latter part of March and con- 

 tinue well into April. When not disturbed, the same burrow is used from 



