Southeast Wild: Eagles gathering early this year
Bald eagles of the Alaska Chilkat Bald Eagle Preserve stand perched once again to play center stage in one of nature's extraordinary exhibitions.
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This year eagles are gathering even earlier and in greater numbers, thanks to an abundant salmon run. At the peak, up to 3,500 birds will congregate along a small stretch of the Chilkat River known as the Council Grounds.
The gathering of bald eagles is the focal point of the annual Alaska Bald Eagle Festival, scheduled this year Nov. 12-16 in Haines.
As autumn advances in the Chilkat Valley and upland temperatures cool, less glacial silt is released into rivers. Edges of glaciers refreeze, river water clears and currents slack. Accelerating salmon runs attract eagles and other species to the Chilkat Valley, long after food sources have been depleted elsewhere.
The Council Grounds cover a three-mile stretch of the Chilkat River near Klukwan, mother village to the Chilkat Tlingit. Here the river seldom freezes.
Porous rock forms an alluvial fan at the mouth of the Tsirku River where it joins the Chilkat. This alluvial fan, an artifact of the valley's glacial past, allows water to percolate deep in the earth where it becomes slightly warmed. Water temperature remains several degrees warmer than it is either up or down river.
In cold years, by mid-November, most of the Chilkat River ices up. Thanks to this warm upwelling, the waters of the Chilkat remain ice-free as the river braids through the Council Grounds. For this reason, the Chilkat River hosts the latest run of chum salmon in the world.
Salmon runs are regulated by water temperature at spawning grounds. When temperatures are low, eggs develop slowly. Spawners have evolved early runs to compensate. When temperatures are warmer - as they are at the Council Grounds - salmon are late spawners.
Into February, when food is scarce elsewhere, fish carcasses are strewed across river channels and wildlife converge on the Chilkat.
Other species making meals of salmon and their associated carrion include brown bear and an occasional black bear, red fox, coyote and river otter. Ravens, magpies, and gulls join adult and juvenile eagles to jockey for position to feed on prime landed salmon.
Dabbling ducks such as teal, widgeon, mallards, pintails and diving ducks, especially mergansers, float the river. Trumpeter swan, dippers, kingfishers, a wide variety of passerines and raptors including the merlin, make showings as well.
Mink and weasel are found along the river, feeding on fish, birds, birds' eggs, and carrion. Numerous small mammals such as red squirrel, voles, shrews, bats, mice and snowshoe hares are also found in the valley. The river supports Dolly Varden char, steelhead and cutthroat trout.
Moose move through the area in November on their way to wintering grounds along the coast. Lynx, wolverine and wolves range throughout the area as well.
Up from the valley floor, high on the Takshanuks, mountain goats make their way along craggy rock outcrops and vegetated slopes. Clouds often enshroud these mountains, which flank the east side of the Chilkat River Valley. But diligence and use of a high-powered spotting scope can help to bring these denizens of high places into view.
Species of the plant kingdom add to the diversity of the Chilkat Valley as well. This is one of the few places in Southeast Alaska where displays of the white fruit of the snowberry occur. Soapberry and paper birch are two other species that attract attention. Sometimes members of the fungus kingdom linger as well. Alaskan Gold, distinguished by a dusting of golden powder on the cap, fruits along the Council Grounds trail.
During the Alaska Bald Eagle Festival, photographers and nature enthusiasts converge on the Valley of the Eagles to participate in workshops, attend lectures and witness eagle antics amid the beauty of the Chilkat Valley.
Although eagles are the main attraction, other species attracted by the salmon and the salmon themselves share the stage. The festival is as diverse as nature itself; this year it includes a concert on Saturday night by violin virtuoso Kim Angelis.
For more information on the festival, call the American Bald Eagle Foundation at (907) 766-3094 or point your Web browser to www.baldeaglefest.org.
• Judy Hall works as a naturalist in Haines and is author of "Native Plants of SE Alaska." Contact the Juneau Audubon Society at http://www.juneau-audubon-society.org.