XANTUS'S SCREECH OWL 285 



Ridgway (1914) describes it as "similar to 0. a. cineraceus but ver- 

 miculations of upper parts finer and blackish streaks narrower, size 

 smaller, and toes more scantily feathered." 



Laurence M. Huey (1926a) has described a new race from Lower 

 California, which he has named Otus asio cardonensis. The characters 

 given are: "Nearest to Otus asio cineraceus, but darker, especially 

 about the head and neck, where the striping is more pronounced. 

 Averages smaller than 0. a. cineraceus and larger than 0. a. xantusi." 

 He gives as the range: "As far as known, the giant cactus (Pachycereus) 

 association of the Pacific slope of Lower California from the vicinity 

 of the hills east of Santo Domingo and San Quintin to the region lying 

 east of El Rosario." 



Dr. Louis B. Bishop evidently thinks this is a good race, for he 

 writes to me: "0. a. cardonensis is the size of xantusi but darker than 

 it or gilmani, approaching cineraceus below, though not quite so heavily 

 streaked and basal portions of feathers paler; browner above than 

 cineraceus; more heavily streaked above than gilmani and xantusi, less 

 so than cineraceus. " 



Griffing Bancroft sent me a small screech owl, collected at San 

 Ignacio with a set of two eggs, which he called xantusi. I compared 

 it with our good series of xantusi and cineraceus at Cambridge and 

 referred it to the latter, which it seemed to match quite closely ; it cer- 

 tainly is not xantusi but may be referable to cardonensis, which I have 

 not seen. The two eggs that were collected with it measure 32.6 by 

 27.9 and 31.8 by 26 millimeters, somewhat smaller than the average 

 for cineraceus. 



J. Stuart Rowley says in his notes on Xantus's screech owl: "These 

 birds were rather plentiful about our camp in Miraflores ; from about 

 dusk until 9 o'clock in the evening screech owls were heard calling 

 noisily. From that time on the owls became quieter — no doubt food 

 hunting and not courting. More than a dozen specimens were taken, 

 most of them from woodpecker holes in cardons, while we were going 

 through the routine of ladder climbing and chopping from cardon to 

 cardon." 



Nesting. — Mr. Rowley took five sets of eggs, in various stages of 

 incubation, near Miraflores from May 11 to May 20, 1933. He says 

 in his notes: "The nesting cavities were old woodpecker holes in car- 

 dons, usually about halfway up one of the arms, or 15 to 20 feet from 

 the ground, but one set of two was taken from a hole only 10 feet up. 

 In each case, where a nesting female was taken, the male was either in 

 another hole in the same cardon or as near as he could get to it in the 

 nearest cardon. No signs of food remains were noted. An occupied 

 hole could usually be detected by a telltale feather caught on the edge 

 of the entrance." 



