1877.] 183 [Bend ire. 



Their holes varied in depth and direction ; some were almost straight, 

 others in the shape of a horse shoe, the chamber containing the nest 

 being on a level with the entrance, and in one instance not over a 

 foot from it, although the whole length of the burrow was at least 

 seven feet. Their nests, of which I examined at least sixteen, con- 

 sisted of dry cow- or horse-dung, in small pieces, and spread about 

 one and one-half inches thick on the floor of the chamber, which 

 itself was somewhat larger than the passage to it. The usual num- 

 ber of eggs from eight to nine, in one instance ten. The nests were 

 alive with fleas, and the eggs so discolored by them that they resem- 

 bled more the eggs of the falcons or willow grouse than their natural 

 color. The birds will remain on their nest and allow themselves to 

 be captured rather than leave the eggs or young. They raise but a 

 brood a season. Their food consists almost exclusively of nox- 

 ious insects, particularly crickets, and they are exceedingly beneficial 

 to farmers. I do not recollect of having found the remnants of a 

 single small bird in their burrows, but have seen small frogs and 

 mice; their principal food, however, appears to be grasshoppers and 

 crickets. They commence laying about April 25, and work on their 

 burrows at least two weeks before. Only once have I seen one of 

 the birds at work. It pushes and scratches the dirt backwards with 

 its feet. That they live in harmony with rodents and rattlesnakes 

 is not my opinion. A snake may occasionally enter one of their 

 burrows, but it certainly is never a welcome visitor. I have never 

 found any other living animal in their burrows, and I have examined 

 many. During the breeding season the male utters a call-note resem- 

 bling that of the European cuckoo (C. canorus L.), and scarcely dis- 

 tinguishable from it. Their eggs are not as round, but glossier than 

 owls' eggs generally ; some are considerably pointed, a rather un- 

 usual shape for eggs of the owl family, and they measure from 1.35 X 

 1.09 to 1.20 X «98 of an inch. Their color after washing them is 

 pure white. 1 



107. Falco polyagrus (Cassin). Prairie Falcon. 



Not at all rare during the migrations of the water fowl. A few 

 breed in this vicinity, but I have been unable to find their nests. It 



1 Another owl which is unquestionably found here, but which. I have not seen, 

 is Syrnium cinereum Aud. It breeds in the Blue Mountains, near Fort Lapwai, 

 Idaho; as I obtained a young bird there just able to fly, in the early spring of 

 1870, from an Indian. I kept it over a year. It became quite tame and useful, 

 being a perfect terror to rats and mice,, and keeping the granary at the post 

 free from these pests. 



