17 February 2006

A beaver dam

This is the largest beaver dam I have seen. According to the only authoritative source I have on beavers, E. R. Warren's 1927 book The Beaver, beaver dams could be from a few feet to thousands of feet long. He mentions one dam that was 2140 feet (about 700 m) long.

Warren explains that in the beginning of a dam, beavers lay the sticks and brushes longitudinally. Only after a dam is completed may they put sticks on it transversely. In this dam most sticks appear to be positioned longitudinally.

This dam is in Black Hill Regional Park in Germantown, Maryland, in an area where beavers have been active for several years. I will be posting more beaver-related pictures in the future.


bev said...

That's quite a substantial looking beaver dam. Up here in eastern Ontario, we see many dams, some of which are are quite large or unusual in configuration. One of the best locations for viewing unusual dams is in Frontenac Park north of Kingston. The park is on the Canadian Shield and encompasses many interconnected lakes bordered by high granite ridges, etc... I've posted a couple of photos of dams seen in the park at the following links in case you are interested in taking a look. This dam holds back quite a good-sized pond -- the other end of this dam actually extends quite far to the right in this photo, but is obscured from view by trees. It's actually quite high - if you're standing below, it's probably at least shoulder height. This dam is not very wide, but makes up for that in height. It is holding back quite a large lake between two high ridges (It's in the area known as the Moulton Gorge). Unfortunately, it wasn't possible to show the full height of the dam, but when you're standing on the timber bridge that crosses on the downstream side, it's quite far to the bottom, perhaps another 8 feet or so (far enough that you definitely don't want to fall from the bridge!). In the same park, there is an area where there are several dams within about a one-kilometer stretch where a creek passes through a gorge. If you visit when the beaver are active, it is quite a sight. This last photo, I include just because it may be of some interest on the topic of beaverworks. Over the course of several weeks one winter, we saw 3 threes about the size of this one, felled at the edge of a large pond at another park north of Kingston. It takes the beaver some time to take down a tree of this size. Hope these links worked. I look forward to seeing any more photos which are posted of dams and/or lodges. -- bev


Thanks for the links & info. I have seen standing trees much larger than the one in your photo that were gnawed all around by beavers. In fact, I photographed one yesterday. I may put that picture up one day next week.

Anonymous said...

I have some beaver pics I could post

Anonymous said...