Northland Nature: A recent visit to a beaver pond reveals..
The snow and strong north winds that hit the region Nov. 18 ushered in some changes for this month. Up until this time, November had been very dry with less than a quarter-inch of precipitation, and no snow. And the temperature that included some record setting highs were far above normal. But at about noon on the 18th as I was out walking in this cool light rain, I noticed the temperature sliding down and, subsequently, the rain changed to a sleet-freezing rain mix and then became all snow. The snow continued for the rest of the daylight hours into the darkness. Though amounts varied much in northeast Minnesota, we received about four inches of a ground cover — and things changed.
This snow cover, even though it was on an unfrozen ground, meant that AutWin — the time between the leaf drop and a snow cover — was coming to an end. Thirty days: Oct. 18 to Nov. 18. Conditions were excellent this year for walking nearly anywhere in the woods. But the snow with the cold brought on other happenings as well. I had been watching several ponds, swamps and lakes as these days went by.
As recent as the morning of Nov. 18, all were free of ice, though some of the small ponds had frozen and thawed earlier. Now, with the coming of the sub-freezing temperatures, they were holding a coat of ice. The ponds and swamps were covered, but many lakes, with their large volume of water, were still largely devoid of ice. And I noticed a change with visitors to the bird feeders. Nocturnal visits from flying squirrels began Nov. 15 with a couple of bold squirrels. They quickly spread word among these agile gregarious critters and by the 20th, we observed 10 at time. In the daytime, gray squirrels mixed with the birds and I saw a smaller red squirrel here too. The finches that had only sporadically come by before now became regulars. Both flocks of purple finches and goldfinches became part of the daily feeders near the house. Will they last throughout the winter? With all these changes — cold, snow and the beginning of the freeze up — it was time to visit to a beaver pond.
Each November, I like to wander through the woods and adjacent field to a favorite beaver pond. This year, I was able to observe a few others as well. I like to see if the beavers are still present and how well prepared they are for the coming winter season. Three beaver lodges that I went to in past weeks revealed newly cut branches on the top with saplings in the nearby water to serve as food. None were large, but each showed activity. Often in the previous weeks of AutWin, I was able to watch the beavers as they swam by.
As I went towards the large beaver pond, I walked in the new snow cover. AutWin may be over, but now the next chapter in the seasonal changes begins. Though I cannot see many of the low plants that I saw in the woods last week, I could see the animal tracks that tell of their activity during these recent days and nights. Even before I left the yard, I found footprints of deer, squirrel, deer mice and shrew. Within the woods, I noted where a ruffed grouse and fox have passed and a runway of snowshoe hare. Out in the field, I found the tunnel openings in the snow made from underneath by the local field mice. These vole holes are always very common early in the snow season. Arriving at the beaver pond, I saw a few coyotes had left their tracks as they moved along the shore. A more adventurous raccoon tried walking on the new slushy ice. And out in the center of the pond, I saw what I came here to observe: the beaver lodge.
The structure is large and solid. Looking it over, I saw the aquatic dwelling site has many recent cut branches on it; the beavers have worked much in previous weeks to reinforce the strength of their home. Nearby in the water are many branches and twigs sticking up above the pond’s surface. This large gathering of woody material tells of a well-stocked cache of food that allows the beavers to have meals all winter. Though the cache is wet and cold, it does give enough substance and nutrition for these large water rodents. The entire pond was covered with ice, except for a small open space near the lodge. Here the beavers are able exit from their unique house if they desire to do so. (I have previously found their tracks on the nearby shore, but not this time.)
From the size of the lodge and cache, it looks like a whole family will be wintering here. I have visited this beaver pond every November for years and nearly always I find what I saw that day. They appear to be doing fine. It was a good walk and visit to the beaver pond and I wish them well for the coming winter.