172 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



numbers are five, six, or seven. The eggs vary in shape from oval to 

 elliptical-ovate. The shell is smooth, or very finely granulated, with 

 very little, if any, gloss. The color is white, or very faintly creamy 

 white. The measurements of 56 eggs, in the United States National 

 Museum, average 39 by 31 millimeters; the eggs showing the four 

 extremes measure 44 by 32.5, 40 by 33, 37.5 by 29.5, and 38.5 by 29 

 millimeters.] 



Young. — The incubation period according to Bendire (1892) is 

 about three weeks. F. L. Burns (1915) states it to be 21 days. Both 

 sexes incubate and take care of the young. According to Urner (1923) 

 the young fly in from 31 to 36 days after being hatched and remain 

 in the vicinity of the nest for six weeks, although they stray from it 

 and hide in the surrounding grass long before they can fly, sometimes 

 as early as two weeks from hatching. Owing to their protective 

 coloration, they are found with difficulty in the grass, and as they 

 stretch out motionless on the ground this difficulty is increased. 

 When aroused they turn on the back and fight. Mabel Densmore 

 (1924) describes the actions of a young bird full grown but unable to 

 fly that she discovered, "a bundle of feathers, dumped down in the 

 short prairie grass, with no semblance to a bird except the eyes." 

 While the parents flew excitedly around, the young continued to 

 "play possum" and could be moved about and handled freely without 

 showing a sign of life except in its eyes. 



Nearly all the young of short-eared owls found at or near the nest 

 differ in size and in development of plumage. Aretas A. Saunders 

 (1913) measured each of nine young of one pair and concluded that 

 their ages ranged between 3 and 14 days. He also found that each 

 owl at about the age of two weeks strayed from the nest, going farther 

 and farther each day even to a distance of 100 or 150 yards. He was 

 always able to find the young by the action of the parents in feigning 

 injury nearby. 



Urner (1923) concluded from his observations in the salt marshes 

 of New Jersey that short-eared owls sometimes move their eggs or 

 helpless young to escape unusually high tides, and it is probable that 

 when the eggs are destroyed by high tides or prairie fires, a second set 

 is laid. 



Urner (1921) describes the "wounded bird" actions of a short-eared 

 owl flushed from a nest of young in New Jersey: "The first bird 

 flushed strove vainly by imitating injury and distress to draw me 

 away, these exhibitions including sheer drops or tumbles from the air 

 and flutterings and cries with wings outspread while on the ground. 

 When not thus engaged the bird maintained a position directly over 

 head facing the wind. The second adult when flushed from the nest, 

 joined the vigil overhead." The wounded-bird act differs in intensity 

 and may or may not be accompanied by calling. On one occasion 



