FAUNA OF THE ALEUTIAN ISLANDS AND ALASKA PENINSULA 113 



In still another phase, which is quite advanced, the head is 

 white, speckled with a blackish hue. The beak is a dull-yellowish 

 tone — perhaps best designated as tan, somewhat streaked with 

 a slaty tone. The lower mandible is bright yellow at the base. 

 The cere is a mixture of gray black and yellow. The eye is 

 yeJlow (as in the adult), the eyelid is a brighter yellow, the 

 preocular area is pale yellow, and the gape is a rich, bright 

 yellow. 



These are the advancing stages in development, the transition 

 from dark "soft parts" to the characteristic yellow of the adult, 

 but it was not possible to allocate all of these plumages to age 

 groups. 



Nesting 



Trees are absent in the area except in a limited portion of 

 the base of Alaska Peninsula, therefore nests are placed on cliffs 

 or pinnacles, or on low ground. Many nests are inaccessible to 

 man by ordinary means of climbing. Frequently, a nest is placed 

 on the top of a pinnacle, which sometimes is separated from an 

 adjacent cliff by a narrow chasm, and which is surrounded by 

 water, at least at high tide. At times, the nest is placed on a 

 cliff, where it may be fairly accessible to man. In one case, on 

 Buldir Island in 1936, a nest was found on a small rock outcrop 

 on a slope, where one could walk to it without climbing. The same 

 place was visited the following year; the former nesting site 

 was abandoned, and the eagles (probably the same pair) had 

 made their nest on the flat grassy valley bottom below. There 

 was not even a hummock at the nest location. 



In 1925, on Unimak Island, a nest containing eggs was placed 

 on the top of a smooth sand dune. It is interesting to note that 

 on June 9, 1941 (16 years later), Beals and Longworth re- 

 ported finding an eagle's nest on a sand dune in the same 

 locality. As a rule, eagles seek inaccessible locations on cliffs and 

 obviously prefer pinnacles. 



Nests are generally built by assembling a layer of dried grasses, 

 mosses, and other vegetable debris. Sometimes kelp is used. 

 Kelp nests are rimmed with the dried stems of Heracleum and 

 Ligusticum, which are the largest material available in lieu of 

 twigs from trees. In some cases, however, the eagles use sticks 

 from the driftwood on the beach. 



Eagles build various types of nests. The nest on the sand 

 dune, already mentioned, consisted of a cavity that was 360 

 mm. wide and 130 mm. deep, heavily lined with dry grass, bits 

 of moss, and a small amount of dead eelgrass from the beach. 



