KILBUCK AND AHKLUN MOUNTAIN BIRDS 



149 



Table 20. Change in density or numbers of species in response to 



mining activities. 



Increased densities 

 or numbers 



Common name 



Decreased densities 

 or numbers 

 Common name 



No change 



Common name 



Ruffed grouse 

 Semipalmated plover 

 Wandering tattler 

 Mew gull 

 Arctic tern 

 Tree swallow 

 Violet-green swallow 

 Cliff swallow 

 Common raven 

 Yellow wagtail 

 Blackpoll warbler 

 Northern waterthrush 

 Wilson's warbler 

 American tree sparrow 

 Fox sparrow 

 Snow bunting 

 Rusty blackbird 



Downy woodpecker 

 Three-toed woodpecker 

 Olive-sided flycatcher 

 Alder flycatcher 

 Black-capped chickadee 

 Boreal chickadee 

 Arctic warbler 

 Ruby-crowned kinglet 

 Swainson's thrush 

 Varied thrush 

 Yellow-rumped warbler 

 Savannah sparrow 

 White-crowned sparrow 

 Dark-eyed junco 

 Pine grosbeak 



American robin 

 Orange-crowned warbler 

 Common redpole 



that used primarily riparian habitats in the interior nested later at increas- 

 ing altitude (e.g., cliff swallow). Several species that nested both in the 

 interior and on the coast apparently nested about the same dates in both 

 locations (e.g., tree swallow, gray-cheeked thrush); however, others 

 nested later on the coast than in interior valleys (e.g., common raven, 

 orange-crowned warbler). 



Variations among years in numbers of birds and breeding success 

 were evident for several species on the Tuluksak River. Diving ducks and 

 mergansers, some shorebirds, and swallows had variable combinations 

 of reduced numbers, later breeding dates, and apparently reduced nest- 

 ing success after the cold springs and the late-May and early-June snow- 

 storms in 1962, 1978, and 1979. Conversely, breeding by resident and 

 migrant passerines was exceptionally early in 1983 (e.g. , American robin, 

 pine grosbeak). Red fox predation on ducklings, especially goldeneye 

 ducklings, was severe in 1983 following the snowshoe hare population 

 crash of 1982. Similarly, the numbers and nesting success of the great 

 homed owl, northern goshawk, and golden eagle were greatly altered by 

 the snowshoe hare population peak of 1981 and crash in 1982. 



The influence of human activity was evident for several species at 

 the Tuluksak River (Table 20). Numbers of several species varied with 

 the amount of garbage available for their use (e.g., common raven, rusty 



