Next Saturday morning the Audubon Society's bird walk will be in the Mendenhall Recreation Area, with the route mainly circumnavigating Moose Lake. Yesterday's walk was on the Moraine Ecology trail with a visit to Norton Lake. This area, just in front of Mendenhall Lake and Glacier, is also known locally as the Dredge Lakes area, and is on most local birders' "A" list for places to bird. You can find species here that are difficult to find elsewhere in Juneau.
Birders will meet at 7 a.m. in the parking area on the Back Loop Road next to the Mendenhall River Bridge. There we will walk along the right side of the river to the outlet of Moose Lake and then work our way around the lake, with a probable diversion over toward Norton Lake, until we hit high water due to those very busy beavers.
Target birds for an early June walk around Moose Lake include ringneck duck, hooded merganser, solitary sandpiper, Vaux's swift, Western wood peewee, warbling vireo, American redstart, and Northern waterthrush.
This area, managed by the U.S. Forest Service, used to be a challenge for hikers, as the myriad of wandering trails and low relief made it relatively easy to get disoriented. I learned the area well enough early on due to some of my fisheries responsibilities at Fish and Game, and I felt just a tad smug when I'd hear about people getting lost and ending up on the spur road when they couldn't find their way to their car parked back by the river on the Back Loop. The Forest Service has sort of ruined my fun with the countless "You are here" signs, but they probably do serve a good purpose.
A few long-time local naturalists, such as Rich Gordon, and probably most kids with an outdoor bent that grew up in the Mendenhall Valley, know the area like the back of their hands, but some birding buddies of mine really only started zeroing in on the place after June, 1993, when two solitary vireos, now named Cassin's vireo, were found near Moose Lake and Norton Lake.
The glacier forelands area contains habitat markedly different than our typical coastal spruce-hemlock forest. Approximately 250 years ago, the Mendenhall Glacier extended down the valley about 2.5 miles further than where the terminus of the glacier is today. Since then, the glacier has been retreating, exposing bedrock and depositional materials left by the melting ice.
Over time, plant communities have developed as rock and sand substrates turned into soils, and we had a shift from lichens and mosses, to willows and alders, then to spruce and hemlock; this is called succession. If you walk throughout the area, you will notice that as you get closer to the glacier and approach the shores of Mendenhall Lake, you witness a marked change in the vegetation and experience different successional vegetative stages or zones. The dense willow, alders, and cottonwoods, along with the abundant water, make the area rich in food for birds and good nesting habitat.
Next Saturday's walk will focus on the Moose Lake area. Moose Lake is only one of many small lakes in the area but it might be the most well known. Back in the 1970s the Sport Fish Division of the Alaska Department of Fish and Game conducted a large-scale salmon enhancement program, using Moose Lake for rearing stocked juvenile king and coho salmon. The program was terminated after several years.
There is still a fish trap below the outlet of the lake that is used by the Forest Service and Fish and Game to monitor the salmon, trout, and char that use the Moose and Dredge Lake waters for spawning and rearing.
But, getting back to birds, in addition to our target list above, many other more locally common species can be found around Moose Lake, and then too, there is always the chance to find something really unusual. Is it a yellow warbler or will it be a black-and-white warbler? You never know what will pop out of that next alder or willow just around the bend.
Mark Schwan will lead the Saturday bird walk to Moose Lake. For information on other Juneau Audubon Society nature walks see http://www.juneau-audubon-society.org