338 BULLETIN 170, UNITED STATES NATIONAL MUSEUM 



other birds, that being a small bunch of quail feathers at the base of the cliff, and I 

 am sure that birds form but a very small percentage of their food. Otherwise we 

 would undoubtedly have found some evidence in the line of feathers in or around 

 the nest. From all my observations of this pair of birds, extending over a long 

 series of [thirteen] years, I would say that they were far more a benefit to the farmer 

 and orchardist than a menace, in spite of the unfavorable reputation this species 

 generally bears. 



Of course, this owl will occasionally pick up chickens. On that 

 point Grinnell and Storer (1924) tell us: "The Pacific Horned Owl has a 

 reputation for feeding on poultry, particularly in outlying communities 

 where the fowls are in the habit of roosting in the trees in the barnyard. 

 Mr. George Smith, our packer, told us that in his experience a horned 

 owl would not ordinarily pounce directly down on a sleeping hen, but 

 'would alight on a limb where a number of chickens were roosting. 

 Then it would crowd against the birds until the one on the opposite 

 side was forced to fly,' whereupon the owl would also take wing and 

 catch its prey when the latter was in motion." 



Behavior. — Horned owls have the curious habit of puffing out their 

 feathers when intruders are near, so much so that many persons think 

 they are always that way. But E. L. Sumner, Jr., writes us that 

 "Bubos are like screech owls in that when undisturbed their feathers lie 

 flat, their ears stick up higher (by comparison), and they look slimmer 

 and less birdlike. This one was roosting on a slanting limb of a dense 

 willow over water, and after I had sat still for half an hour, it lost fear of 

 me and lost its original puffed-out appearance." 



Although I have found Pacific horned owls so averse to leaving 

 their nests that I could almost touch the nests before they would 

 leave, Grinnell and Storer (1924) say: 



Horned owls, wary birds more often heard than seen, usually will not permit of 

 close approach. It seems probable that in detecting the presence of people they 

 depend fully as much on hearing as on sight. At Lagrange, Mr. Dixon tried 

 several times to get near a horned owl heard regularly on several successive even- 

 ings in a certain steep-sided, tree-clothed ravine. Keeping entirely out of sight 

 he tried to approach behind a ledge of rimrock; but the owl, seeming to hear his 

 footsteps, flushed while he was some distance away and still completely out of 

 sight. These owls begin to stir about at dusk and at that time are wont to take 

 commanding positions on the bare tops of dead trees whence they can watch or 

 listen for prey and detect the distant approach of enemies. Their activity extends 

 throughout the night and until late dawn. 



There has been some discussion as to the territory concept of these 

 birds, and Dr. Loye Miller (1930) reaches the following conclusions 

 after many experiments: "Bubo hoots from a point within his chosen 

 territory. Within that territory he generally responds quickly to 

 the note of a supposed invader. Calls from without his estates do 

 not bring him to the spot though they may rouse him to send out his 

 own challenge. The male bird is the more aggressive and is recog- 

 nized by the deeper voice and more regular cadence. * * * When 



