DUSKY HORNED OWL 331 



the data at hand, sets of three are commoner than sets of four. The 

 measurements of 26 eggs average 55.1 by 46; the eggs showing the 

 four extremes measure 60 by 47.7, 52.7 by 43.4, and 53.1 by 42.4 

 millimeters.] 



Young. — Owlets are usually hatched out in March after an incubation 

 of approximately 28 days. About two months later they leave the 

 nest and are then taught to hunt by the parents. 



Plumages. — The development of their plumage is much like that of 

 the Montana horned owl. Perhaps the coloration of adults of this 

 form shows more variation than other subspecies ordinarily do. Per- 

 haps because the dusky horned owls live in a rainy, cold forest, their 

 plumage is thicker and heavier. Bowles (1918) says: "One markedly 

 noticeable feature * * * is the great luxuriance of feathers. 

 In the made-up skin this is seen to best advantage about the legs 

 and feet, where the hair-like feathers closely resemble a long and 

 heavy coat of fur. Looking over my series of these owls taken in the 

 past few years I can find none that are nearly as well feathered as 

 those of the present season. This may, perhaps, suggest a very 

 severe winter, but up to date it has been about the mildest that I have 

 ever seen here." (December 17, 1917.) 



Food. — Although it is known that the dusky horned owls devour 

 great numbers of mice, bouse rats, various species of squirrels, and 

 skunks, their life in the dense, giant tree forests gives them added 

 opportunities to destroy birds. Perhaps this tendency has been too 

 greatly commented upon, most of the notes we have being from game 

 wardens and others antagonistic to the Raptores. Bowles (1916) 

 speaks of the dusky horned owls as preying upon wood ducks and 

 mallards and says he "has found the remains of Sooty Grouse, Oregon 

 Buffed Grouse, Ring-necked Pheasants, and Steller's Jays" at the 

 base of a nesting tree after the young owls have left. As for myself, 

 I have noted more of a tendency to hide uneaten prey and return to 

 it again later. As this return is not invariable, it might be more 

 accurate to say that the dusky horned owl often returns to uneaten 

 prey if it has not been able to make a fresh kill. At times, I have 

 found this subspecies hunting in couples. Racey (1926) reveals 

 something of the boldness and ferocity of this owl when he writes: 

 "One evening when my family was returning to camp at dusk, one 

 of these Owls flew down and tried to seize our small Pekinese dog and 

 when driven off flew only a short distance away and perched on the 

 limb of a dead tree." 



Behavior. — Aside from living in the humid Pacific coast zone, the 

 dusky horned owls differ little in behavior from the western subspecies 

 described elsewhere. They may, perhaps, be a little more given to 

 daylight movements than others, owing to the natural darkness of 

 their chosen habitat. 



