For the first time in the years that I have been engaged in nature study in Eliza Howell Park, I am now seeing signs of beaver activity. There are some 20 small trees near the river (the largest are about 4 inches in diameter) that have recently been cut down and removed.
Beaver were an important part of Michigan’s history; the pursuit of their pelts was a major factor in the movement of Europeans into this part of the country. Unlimited trapping resulted in their being extirpated from this area some 150 years ago.
Some are now returning. In the last decade, they have been found along the Detroit River (including on Belle Isle) and a few have appeared in the Rouge River system. Until now, to my knowledge, none has been reported this far upstream on the Main branch of the Rouge.
I have not yet actually seen a beaver in the park (they are largely nocturnal), but I know of nothing else that cuts down trees and leaves these teeth marks.
Young beaver stay with their parents until 2 years old or so, when they leave to find a mate and establish their own lodge and colony. Perhaps the signs of beaver activity in Eliza Howell mean that a new pair is taking up residence here, for the first time since long before this area was established as a park.
There is a lot I do not know about beaver from personal observation. They were not in the various areas I have walked regularly during my life and my observations of them when visiting other locations were limited. There is much for me to learn.
While most descriptions of beaver lodges are of conical lodges in a pond formed by a dam, they also make lodges in banks, with under water entrances, especially along rivers where the water is deep enough for them to swim under water/ice. The water level in the Rouge in the park varies throughout the year and I do not know whether it sufficiently deep to meet beaver needs. This is what it looked like on my last visit in the area where the beaver had cut trees.
If they stay here, my guess is that they will be “bank beaver,” but one of the things I will be watching to see is whether they act to raise the water level, perhaps by using a current logjam as the start of a dam.
Beaver are able to change the environment in which they live and this has sometimes led to them being considered by some as a nuisance or a pest (for example, when their dams lead to flooded roads). Their overall impact on ecosystems and on sustainability has, however, been viewed by most researchers as very positive, as evidenced in a widely-endorsed, and very readable, book published last year.
I will also be looking for additional signs of their presence and of their behavior. So far I have not seen clear tracks in the mud, perhaps because most of the mud along the river is currently covered with leaves. The hind track (webbed) is reported to be about 6 inches long and the front about 3 inches. These drawings are from The Peterson Guide to Animal Tracks.
I cannot say definitely that beaver have taken up residence in Eliza Howell Park, but I will now have a different answer when asked whether any beaver live here.
I have been saying “not yet,” hoping that they would show up one of these years. Now I can say “there are definite signs; let me show you.” Perhaps soon I will be able to give an unqualified “yes.”