NORTHERN BALD EAGLE 339 



sticks with usnea on them, a sprig of green white pine, and numerous 

 bits of white down. The two eggs which it contained were one-half 

 to two-thirds incubated (pi. 91). 



On an island in Jericho Bay, Maine, on April 24, we found two 

 more nests. One was in a dense virgin forest of spruce, fir, and hem- 

 lock; it was a huge mass of sticks built on the broken-off top of a 

 dead spruce and only about 30 feet from the ground; it was well 

 surrounded by taller live trees, admirably concealed from view and 

 in no sense a lookout point. It was apparently unoccupied. The 

 other nest was about 40 feet up in the very top of a dead yellow 

 birch, only 10 inches thick near the base, in an exposed situation near 

 the shore and visible at a long distance. The nest was fully 8 feet 

 high and impossible to reach into without risking one's weight on 

 some very rotten limbs ; the tree was very shaky, and our spurs would 

 not hold in the rotten wood. There was some white down on the 

 nest, and we saw an eagle in the distance, so it was probably 

 occupied. 



The Rev. J. H. Langille (1884) writes of a very unusual nest as 

 follows : "On the bank of Niagara River * * * -was a farm which 

 had not been occupied for several years, and which was some miles 

 distant from the nearest residence. A missing board from the end 

 of the barn giving access to a large quantity of straw in the mow, 

 the Eagles had arranged a nest there, which contained young when 

 discovered by the owner of the property." 



Eggs. — The eggs of the northern bald eagle are similar in every 

 way to those of the southern bird, except for a gradual increase in 

 average size northward. The measurements of 50 eggs from Alaska 

 and Arctic Canada, typical of this race, average 74.4 by 57.1 milli- 

 meters ; the eggs showing the four extremes measure 84.3 by 58.9, 79.4 

 by 63,4, 69.6 by 54.6, and 70.2 by 53.1 millimeters. Four eggs from 

 Iowa average 74.8 by 59.6 millimeters, larger than the Alaska aver- 

 age. The average of 7 eggs from Maine is 76.5 by 56.3, and the largest 

 Qgg measures 81.3 by 57.7 millimeters. The measurements of 35 eggs 

 from Pennsylvania to Virginia average 73.8 by 56.8, 4 eggs from 

 South Carolina 70.9 by 55.4, 4 eggs from Texas 70 by 54.9, and 50 

 eggs from Florida 70.5 by 54.2 millimeters. A comparison of these 

 figures with the average measurements of birds given elsewhere adds 

 strength to the theory that the eagles of the northern half of the 

 United States should be referred to the northern race. Strangely 

 enough, the measurements of 16 eggs from southern California and 

 northern Lower California average 75.3 by 57 millimeters, fully as 

 large as the Alaska average, indicating that the northern race ranges 

 far south on the Pacific coast. 



Young. — Dr. Herrick's careful and prolonged studies of eagles' 

 nests have added greatly to our knowledge of the home life of these 



