KILBUCK AND AHKLUN MOUNTAIN BIRDS 



49 



and Goodnews and Chagvan bays. Eagles were also found in summer at 

 Cape Peirce during 6 June-6 July 1970 (five observations, plus two 

 observations 25-29 June 1970 by H. P. Brokaw, unpublished); on 27 June 

 1973 (one observation); on 14 June 1981 (one observation; D. R. Herter 

 and D. Lloyd, personal communication); and on 5 July 1984 (one obser- 

 vation; D. R. Herter et al., personal communication). Eagles seen along 

 the coast in fall include one on 29 September 1971 Q. L. Hout, personal 

 communication), four observations at Cape Peirce from 25 August to 

 20 September 1973, and one at Nanvak Bay on 6 October 1981 (R. E. Gill 

 and R. King, unpublished). Birds wintered at the Salmon and Tuluksak 

 rivers (C. Awe, J. Bloomquist, and C. Clark, Sr., personal communication). 



We found 62 nests, which were either on riparian banks, cliffs, or 

 canyons (37), hillside rock outcrops (19), or old dredges (2); in spruce 

 trees on or near riparian clilfs (2); or on the ground among boulders (2). 

 Most nests (60%) were above or north of timberline, but rarely above the 

 limit of subalpine scrub. Nest altitudes were 60-680 m asl with a mean 

 of about 300 m asl. Adults foraged in June-September at edges of subal- 

 pine scrub, alpine tundra slopes, and rarely in open areas below timber- 

 line. At the Tuluksak River, subadults in summer and adults in winter 

 foraged at the edges of woodland-shrub habitats in valley floors and 

 dwarf shrub mat. 



On the Tuluksak and Kisaralik rivers, 32-35 pairs of adults, 2 pairs 

 of subadult females and adult males, 4 unpaired adults, and 4 unpaired 

 subadults or immatures were present over 10 years of thorough surveys. 

 Annual occupancy of l6 golden eagle territories at the Tuluksak and 

 Kisaralik rivers was greater than 90%. At the Kisaralik River, an average 

 of 57% of five eagle territories surveyed over 7 years were occupied by 

 nesting birds each year (B. J. McCaffery and R. D. Ernst, unpublished). 

 We found four territories along 48 km of streams at the Tuluksak River, 

 and the centers of adjacent territories were 5.6-9.6 km apart. At the 

 Kisaralik River, the centers between 12 adjacent territories averaged 

 6.2 km apart (range, 4.8-9 0 km). Eleven broods of small young averaged 

 1 .7 young (range, 1 -3). Of 34 pairs of eagles on the Tuluksak and Kisaralik 

 rivers, 1 5 (44. 1%) fledged 1 .7 ± 0.2 young per pair (range, 1-3). All young 

 were reared in the 5 years of highest hare density, including 2.4 young 

 per pair in the peak year, 1 981 . Ten nest failures included pairs that failed 

 because subadult females did not lay eggs (2), adult females did not lay 

 after a hare population crash (2), eggs failed to hatch probably due to 

 disturbance by humans (4), predation of young (probably a wolverine, 

 [Gulo gulo\) (1), and young taken by humans (1). Three pairs had eggs 

 hatch from 14 to 23 May, and young fledged from 8 July to 10 August (1 1 

 nests, median date of 23 July). Two young were still in their nest on 

 24 July 1984 on the Kisaralik River (D. A. Boyce, Jr., and S. J. Fristensky, 

 unpublished), as were young in four nests with two (two nests) and one 



