Beavers: Prominent Players in American History
Prior to the appearance of Europeans, beavers in North America are estimated to have numbered between 60 and 400 million. Then, beavers were an important to local Indians who found them to be an important source of food, tools, medicine, and clothing. Examinations of primitive camp sites show that only the remains of White Tail Deer outnumber those of Beaver. By the early 1800’s the beaver top hat was all the rage and pelts were in high demand in Europe. This demand helped drive the development and colonization of early America and sealed the fate for beavers in many parts of what is now the eastern United States. By the mid 1800’s beavers no longer existed in most of the northeastern United States and by the 1900’s beavers in North America only numbered around 100,000. As this happened, beavers in Bristol were also wiped out. This is a sad tale; but if you understand the ecology of this situation, you will realize how truly terrible this was.
Beavers: Keystone Species
Beavers are what ecologist consider a “Keystone Species”. Basically, this means that as beavers modify stream habitat with their dams, they create habitat for other species. When beavers locate in forested areas (as was often the case in early America) they begin a successional cycle. As the cycle progresses new assemblages of species arrive and make use of the habitat created by the beaver. Initial flooding and gnawing kills trees that once lived near the stream. This may sound bad, but it creates habitat for numerous species. Once decay softens the wood, various species of wood peckers use the flooded timber for feeding and nesting. Abandoned woodpeckers nest cavities offer Wood Ducks nesting habitat where they can raise their young. Other secondary cavity nesters also use these snags (dead trees). Screech Owls, Tree Swallows, Black Capped Chickadees, Nuthatches, and other non aquatic species nest in the cavities left by the wood peckers. Standing dead timber is also a great place for Great Blue Herons to establish a rookery (group nesting site). Exfoliating bark provides homes for bats who then feed on the insects that grow in and around the wetland.
As time passes, the beaver pond fills with silt. As a result, aquatic vegetation begins to appear and a new class of wildlife species appears. Woodcock show up to probe the soft soils for worms. Black Ducks and Mallards can dabble in the shallows. Mink quietly stalk the banks looking for prey. River Otter come to stalk fish and amphibians. Amphibians use the calm water as a place to lay eggs.
Reading that I have been doing lately has also brought to light the benefits for aquatic species. While the warming of water in the pond can be detrimental for species like trout, it benefits warmwater species like trout and sunfish. The trapping of silt in the ponds improves habitat for many species downstream. Without the beaver pond this silt would pass on and suffocate the eggs of countless organisms downstream. My reading seems to suggest that species that now migrate to headwaters to find spawning substrate were once able to do so downstream of beaver dams. Unfortunately, many see the current “Free Flowing” river system that we have today as the norm and beavers as troublesome invaders. This is not the case. The flora and fauna of our region evolved in harmony with beavers and are adapted to coexist.
Even local plant species have adapted to life with beavers. Willows, Silky Dogwood, and Buttonbush are all wet site shrub species that probably evolved with beavers. All these species can root when cut and pushed into the mud. Often the beaver does just that, during it’s feeding and construction activities.
Saving People from Flooding
In addition to their benefits to wildlife beavers have a surprising benefit to man. Their dams create excellent flood control structures. Wetlands are wonderful for stormwater retention. Excess storm runoff can pond in wetlands and reduce peak flows in streams. Unfortunately they are expensive to create. The cost to artificially create flood control wetlands can run between 10 and 100 thousand dollars per acre, and involves an extensive permit and study process. Beavers can successfully build and maintain quality wetlands without a permit.
Current Situation
That brings us to some good and some bad news. Beavers are now present in most drainages in this area. I believe that they are still expanding their ranges due to the fact that they have been showing up in new waters in our region for some time now. We recently have seen them showing up in Steeles Creek Park, near the race track, and the exit 7 area. I am sure that they have shown up in many other spots that I am not aware of. If they find suitable habitat and are allowed to establish themselves it could great for local flooding issues and the ecology of our region. That is the good news. The bad news is that there will undoubtedly be human/beaver conflicts as a result of these expansions.
Save a Beaver
Many times, when a professional is called, the beavers are simply euthanized. Often there just aren’t other good options. There just isn’t any single place where you can take an endless supply of beavers and release them and have a happy ending for both beaver and local landowners. But, since we see this problem coming, we would like to save these incredible creatures by working with willing landowners who would like to improve their streams and recreate lost wetland habitat. I hope that local landowners and environmental enthusiast
Bristol beaver dam and pond