ACES Morning Birding at Hallam Lake 12/2/2025

This morning felt like the true arrival of winter, with plenty of new snow and the start of the season’s snowpack on the valley floor. Birds were quiet, but our observations were high in quality. Mallards in fresh breeding plumage were abundant on the upper pond and lake where they dabbled in the water and a few fed in the small rivulets that flow into the lake system. We found a dipper in the channel near the old beaver food cache site; this bird used the edge of the ice and submerged rocks for perching when it wasn’t swimming in this small area of open water. Chickadees were present in the forest canopy. On our return past the lake, we watched a hatch-year great blue heron hunting in shallow water and part of our group observed a kingfisher. After a warm-up, we walked the lower Hunter Creek Trail where we watched chickadees, pygmy nuthatches, house finches around seed and suet feeders. In Hunter Creek, we saw anchor ice forming and discussed this unique phenomenon in which super-cooled water and frazil ice particles in turbulent water sometimes stick to rocks and other material on the bottom of streams and rivers as a starting point on which additional ice builds. We discussed the basic fact that ice is less dense than liquid water, causing it to float or form at the surface and creating conditions which support aquatic life during the winter season, including the many invertebrates that birds eat. Join us on December 14th for the Aspen Christmas Bird Count!