dress. Hoxie (1910) reports a case 

 of both birds of a mated pair being 

 in Juvenal plumage. 



Dr. Herrick (1932, p. 311) re- 

 corded a female which had four 

 different mates, namely, in 1924, 

 1925, 1928, and 1931. In the latter 

 year, her mate apparently was 

 killed, and after an absence of 1-1 

 weeks she returned with another. 

 They successfully raised a brood the 

 following year. 



The clutch of the bald eagle may 

 vary from 1 to 3 eggs with 2 being 

 the normal number. Frequently 

 only 1 of the young is raised to ma- 

 turity. According to Herrick 

 (1932, p. 318), the normal incuba- 

 tion period in northern Ohio is 34 to 

 35 days. In Florida, Nicholson 

 (1952) established the incubation 

 period as 35 days. The period of 

 egg laying varies greatly from the 

 southern to the northern portion of 

 the bald eagle's extensive range. 

 Bent (1937) has shown that from 

 Georgia and Florida to Texas eggs 

 may be found from the end of Octo- 

 ber to the end of Februarj', with 

 half of the records falling between 

 the dates of December 8 and Janu- 

 ary 27. From New Jersey to Vir- 

 ginia, he found that the spread was 

 from February 2 to May 27, with 

 half of the records falling between 

 February 27 and March 9. Six rec- 

 ords from the area, Maine to Michi- 

 gan, revealed that egg laying took 

 place between April 1 and April 21. 

 In Alaska and Arctic America, 

 eggs were laid from March 24 to 

 June 24, with half of the records 

 falling between May 7 and May 14. 



On the basis of these figures, the 

 median dates of egg laying for 

 Florida, New Jersey, Michigan, and 

 Alaska are roughly, January 2, 

 March 3, April 10, and May 10, 

 respectively. 



In the southern part of the bald 

 eagle's range, should the eggs be 

 removed from a nest or a nest de- 

 stroyed during the egg laying or 

 early part of the incubation period, 

 a second clutch often is laid. The 

 same nest may be used, but usually 

 there is a shift to a new location. 

 Farther north, except j)ossibly in 

 the mild climate of Southeastern 

 Alaska, the shortness of the season 

 and the necessity of finding food for 

 the young over an extended period 

 prevent the laying and hatching of 

 second clutches. 



The nestling life of the bald 

 eagle, as determined by Dr. Her- 

 rick in northern Ohio, lasts from 

 10 to 13 weeks during which the 

 3"oung undergo one change of 

 downy plumage and gradually ac- 

 quire their juvenal plumage with 

 which they leave the nest (fig. 4). 

 Even after the young leave the nest 

 they often remain in the vicinity 

 and at times are fed at the nest 

 site by their parents throughout 

 their first summer. In this respect, 

 the young of the bald eagle are 

 quite different from the offspring 

 of most passerine birds, which, once 

 they have left the nest, seldom re- 

 turn to it. On the other hand, the 

 young bald eagles are not permitted 

 to use their home territory for 

 breeding purposes unless in later 

 years one of them should be mated 

 with a parent. 



17 



