A hard crust on top of deep snow made it exhausting to go off-trail very far. Even with snowshoes, the post-holing was hard going. So our forays weren’t very long. Nevertheless, the curious naturalists found several things of interest.<\/p>\n
There was still some open water in the sloughs, so crossing them was dicey, and we diverted to the Moraine Ecology Trail, which was partially packed down by previous walkers. Here, we noticed new spiderwebs laced across recent footprints and other divots. Even though we did not see the owners of the webs, it was clear that they can be active in cold weather. In addition to these web-builders, we sometimes see jumping spiders huddled on top of snow. Spiders are out and about, but what can they hope to capture and eat? <\/p>\n
[Tracking animal footprints in the snow]<\/a><\/ins><\/p>\n The next day, after much dithering about where to walk, we ended up on the first part of the well-packed trail along Eagle River. This turned out to be quite productive for us.<\/p>\n The first thing that captured our fancy was a snowy, suspended log that supported a few blueberry bushes and at least four stands of the now-dead-and-brown flowering shoots of northern ground cone. This plant has no green leaves, so it cannot photosynthesize carbohydrates for itself. It is totally parasitic, mostly on alder, but occasionally on other species, perhaps blueberry in this case.<\/p>\n [The Mating Game]<\/a><\/ins><\/p>\n Presently, we began to see red — fragments of highbush cranberries in numerous, widespread patches on top of snow-covered logs and hummocks. There were a few whole berries, but in nearly all cases the seeds had been extracted, leaving bits of red pulp and fruit skins. Aha! Pine grosbeaks had been at work! Part of their scientific name reflects this behavior: “enucleator” meaning seed (or nut) extractor, although they also eat many other kinds of seeds, buds and insects. They typically nest in open conifer forests of boreal North America and Eurasia; here, in fall and winter, at least, they regularly enucleate highbush cranberries.<\/p>\n We conjectured that the birds found it hard to handle the frozen fruits while perched in the shrubs (in warmer weather, they commonly process the fruit while perched) and brought them down to the snow. There they may have been able to brace each berry on the hard surface while biting it, or maybe they could use the snow as an anvil for striking it. Since the berries grown in clusters, by yanking on one, the birds may have incidentally brought down a few more, some of which were not opened (but why not?).<\/p>\n