Food of the Long-Eared Owl in Southern Washoe County, Nevada
Food of the Long-eared Owl in Southern Washoe County, Nevada.-On March 5, 1953, a pair of adult Long-eared Owls (Asia zeilsonianus) was found roosting in a single-needle piiion . . at 4800 feet in the foothills of the Virginia Range, 11 miles southeast of Reno, Washoe County, Nevada. Subsequent visits to the locality were made on March 26, April 30, and May 21, 1953. Two birds, an adult and one volant young judged to be about five weeks old, were present on the latter date near an old magpie nest. On the last three trips to the area I gathered 131 pellets from the ground beneath several piiion trees in the vicinity. Because most of the pellets had been protected from the weather by thick pifion cover, the majority of the skulls they contained were well preserved. An analysis of the contents of these pellets follows. Each item listed was represented by a complete skull or by a recognizable skull fragment.
Number of items Per cent of total
Pocket Mouse, Perognathus parvus 18 15.80
Kangaroo Rat, Dipodomys panamintinus 18 15.80
Pocket Gopher, Thomomys talpoides 2 1.75
Thomomys sp. 3 2.64
Harvest Mouse, Reithrodontomys megalotis 15 13.16
Deer Mouse, Peromyscus (maniculatus ?) 21 18.40
Meadow Mouse, Microtus montanus 34 29.82
Jackrabbit, Lepus californicus 2 1.75
Western Meadowlark, Stumella neglecta 1 .88
Total 114 100.00
All of the Dipodomys skulls and all but one of the Perognathus skulls were identified to species on the basis of geographic range. Rabbit remains were frequent beneath scattered pifrons in the area, but I could find only two skulls, neither of which was contained in a pellet.
The locality is situated at the ecotone of the pifion-juniper-sagebrush-grass zones, and is approximately one-half mile from the nearest meadowland. Thus it is interesting to compare the percentage of prey animals of moist, grassy environments (harvest and meadow mice, pocket gophers, and meadowlarks), which totals 48.25, to that of the remaining species of normally dry habitat which totals 51.75. Although the owls roosted in the pifion, about half of the feeding was apparently done in the meadowland area one-half mile distant. Groves of large cottonwoods and willow thickets near the moist area would seem to be suitable for both roosting and nesting of these owls, although no signs of such activity have been noted there.-NED K. JOHNSON, University of Nevada Museum of Biology, Reno, Nevada, July 19, 1953.