One of the first things I noticed was a roadside muskeg in which the shore pines were in sorry shape, with many brown needles. Upon inquiry, I was told that these pines are infected by a fungus that causes needle blight. The fungus kills off mostly the older needles, so an affected pine has only small tufts of newer needles near the branch ends. A serious level of infection can kill the tree. Cool, wet weather favors the production of spores, which are spread by wind or rain-splash, and the spread of this disease. And that’s the sort of weather that has prevailed this spring, it seems.
A flock of several hundred white-fronted geese loafed peacefully in someone’s back yard, while an off-shoot group foraged nervously in a nearby field. These birds were on their way to the nesting ground on the tundra up north. They were enjoying an important way-station on their journey, where they can feed and rest.
A pair of Canada geese seemed to own a piece of pasture, apparently unruffled by grazing horses. But they reacted sharply when a little flock of other geese came in to graze. The small group of new arrivals was a mixed lot—mostly white-fronts, a couple of Canadas, and a sole snow goose. The residents paced back and forth, talking at the unwelcome visitors, who went right on grazing but did not venture much farther into the pasture.
The great outwash plain created by melting glaciers supports numerous stands of willows, most of which have been severely browsed by moose, such that they seldom exceed three or four feet in height. ADF&G has a long-term study of moose ecology and the effects of moose browsing, focused on a set of exclosures that prevent moose access. The willows inside the exclosures look markedly different from those outside: the inside willows are much taller and produce more catkins. The paucity of catkins on the heavily browsed willows may have extended effects, well beyond the diminished reproductive capacity of the willows themselves. Willow catkins are an important source of food (pollen, nectar) for queen bumblebees, which mate in the fall and overwinter in small burrows. In spring, they need to feed so they can produce broods of workers. Bumblebees are important pollinators of blueberries, beach pea, lupine, and many other flowers. So the obvious question is: Does moose browsing significantly reduce the spring food of queen bees, thus reducing their ability to produce healthy broods, and thus impairing the pollination success of various flowers?
There may be other ripple effects of moose browsing. For example: Browsed willows produce fewer leaves and therefore less leaf litter below the shrubs. So we can ask if the reduced leaf litter affects the mosses, lichens, grasses, and herbs that constitute the ground cover. A lower number of leaves on the browsed shrubs should reduce their growth rates, because fewer leaves mean a reduced capacity to synthesize carbohydrates that provide energy. And one has to wonder if the cropped-off willows offer fewer nest sites and foraging surfaces for birds, leading to a lower density of birds than would occur in unbrowsed stands.
A male harrier coursed up and down the deeply incised channel of a tidally-influenced river that runs across the outwash plain; he was probably hoping to snag a shorebird or two. I heard snipe, high in the air, doing their flight display: as they swoop around, the rush of air over the spread-out tail feathers is modulated by the beating of the wings, producing a characteristic sound known as ‘winnowing’. Snipe winnow both on migration and on the nesting grounds, and most of these were probably still in migratory mode. I also think I heard a pygmy owl, tu-tu-tu-ing in the trees. A male robin carried a beakful of worms to his chicks, proving that the robins thought it was spring despite the raw, cold weather.
Another treat was the opportunity to watch three river otters exploring one of the inland ponds near Bartlett Cove. I suspect this was a family of a female with two of last year’s offspring, although there was not much difference in size. Otter families often stay together over a winter and into the next spring. These otters were well aware of our presence and kept bobbing up to peer at us. I was told that river otters are often seen as they travel considerable overland distances in Gustavus, visiting inland ponds (are there fish to be caught??) and returning to the ocean shores.