Windfall Lake was a popular destination on the Fourth of July weekend.
The very nice cabin, with its ultra-fancy outhouse, was occupied by a family of four plus a friendly dog, and we passed several other parties on the trail. This easy trail was in pretty good condition: The mud puddles were almost dry and the planked walkways across the sloughs were not under water.
Our group of hikers kept moving along rather briskly, in hopes of keeping the blood-hungry female mosquitoes at bay. Even those of us who resist applying bug dope were reduced to slathering it onto arms and necks and caps. When two hikers stopped to watch a family of winter wrens, they were met with cries of "Keep moving! Keep moving!"
Winter wrens are a familiar denizen of the forest understory. A tiny (9 grams or about ⅓ oz.) ball of dark brown feathers, usually with its tail cocked up, is often seen flitting from stump to low branch to log. More often, at least in spring, one hears its long, rippling, tinkling song, as the male's entire body vibrates with the effort.
The wrens commonly nest in cavities in old trees, snags, logs, stumps, or creek banks, but they also make use of moss wads on tree branches or the skirts of moss around tree bases. Years ago, we found that moss-wad nests were more common than cavity nests in some areas around Juneau, and many of these were found well above the usual understory location. Males may begin several nests, which a female visits before choosing one to finish to her specifications. Then she lays five or six eggs, which take about two weeks to hatch. Both parents feed the chicks in the nest for about three weeks and tend the fledglings outside the nest for a while longer. The wren family we observed (rather briefly!) was composed of four young ones and two food-carrying adults,who scolded us roundly.
Winter wrens are sometimes monogamous and sometimes polygamous. Around Juneau, one study found that the frequency of polygamous matings varied from 10 percent of males in one area to 78 percent in another area. Most polygamous males had two mates, but a few had three. Monogamy was most common in an area where many nests were located in moss wads more than 10 feet above the ground. Nest success did not vary with levels of polygamy. However, nest success tended to be lower in an area where red squirrels, active nest predators, were more common.
This species of wren breeds all across northern North America (and even out on treeless Bering Sea islands) and usually migrates south in winter to southern parts of the U.S. However, here in Southeast, some individuals may stay all winter, at least in some years. The same species occurs in Eurasia, where it is known as The Wren, because it is the only wren over there.
En route to the cabin, we noted a family of spotted sandpipers on a gravel bar in the river. The downy little chicks ran among the tufts of sedge and were hard to see except when the vegetation twitched. They were tended by an adult, probably the father, because in this species the female often leaves her first mate to tend the eggs and young while she goes on to another male.
We also found a flock of white-winged crossbills, calling in the top of a small spruce along the river. I thought I heard Tennessee warblers singing in the treetops along one stretch of the trail.
Up in the lake, fish were rising, making rings on the water surface. This lake system, including the tributary creeks and the outflow to the Herbert River, is productive of fish and a popular place for anglers. Sometimes it is too popular and spawning stocks become depleted, so fishing then is closed. There is spawning and rearing habitat here for coho, sockeye, cutthroat trout, and Dolly Varden char, and sometimes a few steelhead are reported. The lake is said to provide important overwintering habitat for anadromous dollies and cutthroats.
Mary F. Willson is a retired professor of ecology and a Trail Mix board member.
Juneau Empire ©2013. All Rights Reserved.