138 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



at Fort Harney, Oreg., and the bronzed grackle, at Littleton, Colo. 

 At Barr, Colo., a brood of young magpies left a nest early in May, 

 and within a week a pair of English sparrows started to build within 

 the structure. Afterward a cowbird's egg was found in this nest. 

 Nearly all the birds found laying eggs in these used nests chose ones 

 between 15 and 30 feet above the ground. 



A dilapidated magpie nest 8 feet above the ground in a willow near 

 Pyramid Lake, Nev., held a nest of a gadwall, built of down and con- 

 taining nine eggs (Ridgway, 1877). Near Denver a magpie's nest 

 found by Bradbury (1917a) held seven fresh eggs, and on its flattened 

 roof were three eggs of the black-crowned night heron. Apparently 

 both pairs of birds had started about the same time to nest in the same 

 structure. Another magpie nest 50 feet away contained five long-eared 

 owl's eggs that were being incubated. 



A peculiar association between nesting magpies and other kinds of 

 nesting birds, mainly hawks, has been detected by many observers in 

 many localities. In Alberta Taverner (1919) found magpie nests in- 

 variably in the neighborhood of, or not more than a hundred yards or 

 so from, nests of red-tailed or Swainson's hawks. Bowles and Decker 

 (1931) report that almost invariably one finds a nest of the magpie in 

 the same tree only a few feet from that of the ferruginous roughleg; 

 there is a continual supply of food to be had from the leavings of the 

 hawks. Rhoads (1894) cited Captain Lewis as observing "that the 

 nests of the Bald Eagles, where the Magpies abound, are always ac- 

 companied by those of two or three of the latter, who are their insep- 

 arable attendants." On the Columbia River a magpie's nest was once 

 found by Dawson (1909) in the "basement" of an occupied osprey's 

 nest. He intimates that the magpies derived benefit in having access 

 to surplus food brought in by the ospreys. 



Mammals, of fairly large size, have been found occupying old nests 

 of the magpie. In New Mexico, Oilman (1908) reported four young 

 house cats living in a nest 16 feet up from the ground. A gray fox 

 found resting in the daytime in an old magpie nest near Colorado 

 Springs, Colo., was reported by Warren (1912) on authority of 

 C. E. Aiken. 



Aretas A. Saunders sends the information that magpies sometimes 

 use their old nests as shelter in winter in stormy or windy weather, and 

 he thinks that possibly they use them regularly at night in winter. 



Eggs. — Seven is the usual number of eggs in a set; sets of 8 and 9 

 are not uncommon, and as many as 10, 11, and even 13 have been 

 found in one nest. Small sets in a nest are likely to be the result of 

 some accidental destruction. 



