Dam Mammals

Beavers, that is! Yesterday my favorite librarian and I went with our dog to a café opening in Rutland, Massachusetts. (Read all about our friends at Coffeelands-Rutland on GeoCafes.) To make a proper outing of it, I looked for a place to walk the dog in Rutland, and found a section of the Massachusetts Central Rail Trail, appropriately located on Depot Street, where presumably there was once a depot. 

We rightly guessed that our dog Crumpet would enjoy this wide, shady walkway with us. She is shown here on a causeway between two ponds, one of which I later learned is named Thayer Pond. At the western edge of the pond, I noticed what looked like a beaver lodge, but I was confused. 

The pond is large and the railroad folks had built a causeway next to it over a century ago. I was guessing that the pond was about 10 acres, but checking Google Earth, I see it is more like 40. In any case, it seems it is much too big and too old to be formed by a beaver dam -- whose constructions tend to be on a smaller and more temporary scale.

(Note: the café we were visiting was too new to appear on the map. Coffeelands is at 249 Main Street in Rutland; tell them I sent you!)

In any case, that lodge was too far from the path for us to get a good look without some serious bushwhacking, so we stayed on the main path, and a minute later we saw a much smaller pond with a very definite beaver lodge on it!

Dead trees in standing water are another indicator of possible beaver action, since they are most likely to be upright only in the first few years after inundation. 

We could see the lodge pretty well from the main path. The dam was easy to see, but difficult to photograph. In this image, the dam is only evident by the fact that standing water is present to the left and not to the right.

Looking at the map, we can see that the lodge on the bigger pond is very close to an outlet known as Mill Brook, which is also the name of an inlet on its northeast corner. This is not only further evidence that beavers did not build the big pond, but also provides some insight to what this place must have been like a century or so ago. 

It seems that the lodge that first caught my eye is easily accessible from the unnamed pond just downstream of it. Easily accessible to beavers, that is!

Lagniappe: back to that first time

I should mention that my master's thesis involved in-depth measurements of 33 different artificial ponds in the vicinity of the Miami Whitewater River. I measured them on every available map and aerial photograph and I physically measured the sediment in them. So became fairly adept at identifying ponds and their dams, and can sometimes spot beaver ponds with confidence from New England highways, but I was in this region for 25 years without seeing any. 

So I was happy -- downright giddy -- to see a textbook example of a beaver dam in May 2022, when my favorite librarian and I were on the Vermont Inn to Inn Walking Tour. The dam was much easier to photograph.

This was such a treat -- I stood there transfixed for quite some while.