300 BULLETIN 16 7, UNITED STATES NATIONAL MUSEUM 



long distance, and then only for a few seconds. I can find no au- 

 thenic record of an eagle attacking an intruder at her nest. If dis- 

 turbed during the early stages of incubation, she may desert the 

 eggs but never the young, although she seems quite indifferent to 

 their welfare. Mr. Ray says in his notes: "Many birds resent any 

 interference with their nests and will frequently desert them whether 

 they are in the course of construction, completed, or even containing 

 partial or full sets of eggs. In some cases they have apparently 

 shown their extreme disfavor by casting the eggs out of the nest; 

 while I have never actually seen eagles engaged in taking such dras- 

 tic measures, on a number of occasions I have found eggs on the 

 ground just below the nests where an almost inaccessible situation 

 made it difficult to see how they could have been disturbed by any 

 outside agency." 



Several British ornithologists have, at the cost of much effort, 

 personal discomfort, and risk, spent considerable time studying and 

 photographing the home life of the golden eagle. I would recom- 

 mend reading the published reports of H. B. Macpherson (1911), 

 H. A. Gilbert and Arthur Brook (1925), Duncan MacDonald (1926), 

 and Seton Gordon (1927). Much of what follows is taken from 

 their writings and from the observations of E. S. Cameron (1905 and 

 1908b) in Montana. I regret that space will not permit more 

 elaborate quotations from these interesting accounts. 



E. L. Sumner, Jr., has sent some very full notes on the growth of a 

 brood of young eagles in California, which he measured and weighed 

 once a week from the time they hatched until they left the nest. The 

 loss in weight of the eggs prior to hatching is interesting; on Febru- 

 ary 27 the three eggs weighed 143, 143.4, and 133.7 grams ; on March 20 

 I lie first egg had just hatched, and the other two eggs had shrunk in 

 weight to 128.6 and 126.2 grams. The newly hatched chick weighed 

 1 05 grams. A week later all three had hatched, and the chicks weighed 

 357.3, 232.3, and 98.2 grams, showing that they probably hatched at 

 intervals of two or three days. On April 3 the youngest and smallest 

 chick had disappeared and tlie other two had increased to 1,022.7 and 

 584.7, the older chick being then two weeks old, and ten times as heavy 

 as when hatched. From that time on both birds increased steadily in 

 M'eight, along slightly divergent lines; on May 8, when seven weeks 

 old, they weighed 3,851.7 and 2,801.7 grams. During the next week, 

 they both dropped off over 400 grams in weight, but regained this and 

 more during the following week, so that on May 22, when nine weeks 

 old, they weighed 4,061.7 and 2,981.7. This, compared with 4,169.4, 

 the weight of an adult male, emphasizes the lightness of the smaller 

 bird, probably a male. This was tlie last weighing, as the birds left 

 the nest during the following week. 



