336 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



1908 and 1909 three eggs were laid, possibly indicating that the birds were finding 

 food more plentiful than formerly. 



It seems hard to flush a sitting bird of this subspecies from her nest, 

 even before the eggs are hatched. E. L. Sumner, Jr., writes us that 

 on March 14, 1931, a "bird flushed from three eggs when I shook the 

 tree. She flew to a willow along the same slough, about a fifth of a 

 mile away, and perched in the open on a bare branch, facing me. 

 I left and hid in some willows a quarter mile away. In about six 

 minutes she left her post, flew to a willow nearer the nest tree, stayed 

 there about two minutes, and then flew to the nest tree. She lit 

 directly on the nest, walked to the center, fluffed her feathers, and 

 sat down facing my hiding place." 



Young. — As with other horned owls, the mother Pacific horned owl, 

 who does most of if not all the incubation (Dixon says "turn about") 

 begins that incubation as soon as the first egg is laid. Since the second 

 egg may be laid as much as three or four days later, and the third egg 

 as much as a week later than the first, there will be that much differ- 

 ence in the dates of hatching, and a corresponding difference in the 

 sizes of the owlets. At first the youngsters are weak and unsteady 

 and not aggressive. In fact they seem drowsy and half asleep. 

 Dixon (1914) says that on March 2, 1913— 



the little owl just out of the shell kept up a lusty cheeping, and when I withdrew 

 a short distance, the old owl returned to the nest without delay. On the 5th of 

 March I again visited the nest and found both owlets out of the shell, and both 

 set up a vigorous cheeping upon the old bird's leaving. * * * Upon settling on 

 her young she made a short hissing noise, not unlike that of a goose but more 

 subdued, and the youngsters would immediately cease their complaint. Three 

 or four times she did this and I at first thought it was directed at me, but finally 

 concluded that it was directed at the youngsters, as they then always became quiet. 

 As the owlets grew older the parent birds became wilder, never again allowing 

 the intimacy shown during the hatching period. The young owls developed 

 rather slowly until they were three weeks old, but from then on made a marvelous 

 growth. * * * Seven weeks from the time of hatching the two young owls 

 left their nest for good, taking up their abode in the brush and rocks of the steep 

 hillside. They were still unable to fly more than a short distance. 



Sumner (1929) says that of two very young "the older whimpers 

 feebly, but cannot stand up yet." A week later both birds were 

 torpid, not offering to move or utter a sound. At this stage they may 

 clap their bills feebly. At the age of 16 days, "young birds as dull and 

 lifeless as ever, offering absolutely no resistance and behaving as 

 though sound asleep." At the age of 21 days, the "youngsters hiss 

 and snap their bills when I approach, but are still far from being wide 

 awake." Eight days later "the young birds rear up and snap their 

 bills when I approach, hissing as I draw nearer, and half opening their 

 wings so as to give themselves a deceptively bulky appearance. They 

 are still as harmless as before." At 37 days of age, "both adults were 



