165 



are an excellent index of the food of owls. Dr. A. K. Fisher, of the 

 Biological Survey, has examined 987 pellets of a pair of barn owls that 

 live in a tower of the Smithsonian building in Washington, and in 

 them found the skulls of no fewer than 192 rats (Mus norvegicus), 

 together with those of 554 common mice and 1,508 field mice (Micro- 

 tus pennsylvanicus) . 



Dr. John I. Northrop found a nest of the barn owl on Andros Island, 

 Bahamas. It contained two young owls and the remains of a black 

 rat (Mus rattus). The ground about the nest was covered with 

 pellets which contained remains of the black rat and no other species. 



The great horned owl (Bubo virginianus) is the largest of our resi- 

 dent owls. It feeds mainly on rodents, though occasionally it takes 

 a fowl found roosting in an exposed situation, as on a fence or in a 

 tree. While it occasionally destroys game birds, the rats it captures 

 would probably destroy ten times as much game as the owl. Charles 

 Dury, of Ohio, in 1886 published a letter from O. E. Niles in which it 

 was stated that he counted 113 dead rats at one time under a nest of 

 this bird. 6 



The snowy owl (Nyctea nyctea) is a rather rare winter visitor in the 

 northern United States. It usually arrives when the ground is 

 covered with snow and ordinary food is scarce. Near barns, out- 

 buildings, and stacks it finds its chief subsistence in the common rat; 

 and, if undisturbed, will stay for several weeks in the same locality, 

 destroying many of the pests. Unfortunately, mounted specimens 

 of this beautiful owl are so much in demand that the majority of them 

 fall a prey to the specimen hunter and the taxidermist. The destruc- 

 tion of this bird should be prohibited under heavy penalties. 



The barred owl (Strix varia), the long-eared owl (Asio wilsonianus), 

 and the short-eared owl (Asio flammeus) all destroy some rats ; but 

 as they do not generally nest or live in the vicinity of farm buildings, 

 the rodents they capture are taken chiefly from the fields. Occa- 

 sionally a short-eared or a long-eared owl makes its winter home in a 

 group of evergreens near the farm buildings, and does excellent 

 service in clearing the premises of rats and mice. Evergreens are 

 desirable about a countiy place, if for no other reason than that they 

 attract owls. 



The practice of indiscriminately destroying hawks and owls should 

 be discouraged. Game preservers especially should realize that the 

 birds of prey they kill would, if allowed to live, destroy rats, which in 

 the course of a year do many times as much harm to game as the 

 supposed offenders do. Besides, the birds would destroy also large 

 numbers of mice and injurious insects. 



The Auk, vol. 8, p. 75, 1891. 



& Jour. Cincinnati Soc. Nat. Hist., vol. 8, p. 63, 1886. 

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