Beaver Behaviors

A Day in the Life at Chicopee Lake

Editor’s Note: Don Lane, Elachee Teaching Naturalist and retired environmental scientist will provide insight, each month throughout 2022, about different environs and species in, and around Chicopee Lake, located in Georgia’s Chicopee Woods Nature Preserve, in south Hall County.

Don Lanes Journal Entry: April 2022

Beavers at Chicopee Lake Do What Comes Naturally

In March I had the opportunity to accompany a field trip led by Dr. Jacob McDonald of the University of North Georgia to Chicopee Lake and surrounding areas.  One of the sites we visited was a most impressive beaver dam impounding one of the tributaries of Walnut Creek upstream of the lake. 

There have been beavers in, and around Chicopee Lake at least since I first visited some 25 years ago.  If you are walking across the dam, you may have noticed the drainpipe on the far side (from the parking area).  Upon closer inspection, you may have noticed that the drain is enclosed by a metal cage. This was installed because the beavers were constantly plugging up the drain with pieces of wood.

According to the Greater Yellowstone Resource Guide, “In the wild, scientists have observed beavers making repairs and additions to human-made dams. Beavers hate the sound of running water. It makes them think there could be a leak in their dam. If they hear running water, they will often work all day and night to find the leak and repair it.”

Beavers (Castor canadensis) are a member of the Order Rodentia or the rodents. That means beavers are related to mice, rats and squirrels.  Like most rodents, beavers are intelligent animals and like all rodents, beavers have large upper and lower teeth called incisors.  Unlike human teeth, incisors do not have roots and grow continuously. To keep the teeth from growing into their brains, rodents must grind the teeth. 

Beavers are North America’s largest rodent. They are distinguished from other rodents by their tail. The broad, flat tail of the beaver is used for stability while sitting, feeding or chewing on trees.  In the water, the tail serves as a warning device when slapped on the water and as a rudder for swimming.  Beavers are referred to as sexually dimorphic which means that male and female beavers are indistinguishable. 

Beavers are plant-eaters (or herbivores). During the winter months, their preferred diet is sweet gum, ash, willows, polar, cottonwoods, pines and fruit trees. In the spring and summer, they dine on aquatic plants and tender shoots. 

Beavers reside in either bank dens or lodges. Dens are created by digging a series of holes in the banks of rivers, lakes, ponds, creeks or streams. If banks are not suitable for digging, beavers will build a lodge consisting of piled up sticks. Entrances to a den or lodge are submerged, while the living or denning area is one to two feet above the water level. Beavers use a den or lodge as shelter and a place to raise their young. In Georgia, beavers breed in October through March and, after a gestation period of about 100 days, anywhere from one to four offspring (known as kits) are born.

The most recognized edifice of beavers is their dam and the pond that forms behind it. In his seminal work The Natural Environments of Georgia (published by the Georgia Department of Natural Resources and available on-line), the late Dr. Charles Wharton included beaver ponds as a bona-fide natural environment.

What follows is a paraphrasing of some of the section on beaver ponds from the book.

Beaver ponds occur throughout the state except for the lower part of the Coastal Plain. An explanation for the lack of beaver ponds in the coastal plain is the presence of alligators. If a beaver lives on a small tributary, it will dam the tributary and build a lodge.  If the beavers reside on a larger stream, they will not attempt to dam it and will live in bank dens.  Often beavers will alternate between lodges and dens. 

Black willow and sweet gum can be found along the edges. Sedges such as beaked sedge and owl fruit sedgewith bullrushes, spike rushes, common rushes and cattails can be found close to the banks.  Arrow heads are common.

Studies on the diversity of life in a beaver pond reveal a myriad of animals live in and around beaver ponds. The following is a list of animals found in conjunction with beaver ponds.

  • Fish: small-mouth buffalo, red fin pickerel, chain pickerel, creek chubsucker, golden shiner, sandbar shiner, spot tail shiner, mosquito fish, spotted bass, black crappie, orange-spotted sunfish, large-mouth bass, war mouth, bluegill, spotted sunfish, flier, pumpkinseed, Coosa darter and swamp darter
  • Turtles: stinkpot, loggerhead musk, painted, snapping and yellow-bellied
  • Toads and Frogs: cricket frog, green frog, southern toad, tree frog and bird-voiced frog
  • Salamanders: two-lined, northern and dusky
  • Snakes: king and brown water
  • Birds: king rail, Virginia rail, American bittern, green heron, red wing blackbird, purple grackle, prothonotary warbler, myrtle warbler, red-bellied woodpecker, red-headed woodpecker, pileated woodpecker, coot, mallard, wood duck, black duck, green-winged teal and blue-winged teal
  • Mammals: beaver, muskrat, rice rat, and swamp rabbit

Although beaver ponds sometimes destroy timber, the ponds provide a diverse habitat of open water, semi-permanent water, marsh, and shrub communities. As can be seen from the previous section, beaver ponds do contain a large variety of life. Dr. Wharton speculated that Native Americans may have used drained beaver ponds as cornfields, allowing the beavers to reclaim them periodically. 

Sometimes beavers will abandon a pond. When this occurs, the pond goes through a succession toward a bottomland hardwood forest. Often, beavers will return and repair the dam on such a pond, when alder, birch and willow saplings reappear. One explanation for abandonment and reclamation by beavers is that a beaver will gnaw on a tree for only a certain amount of time. If the tree does not fall, the beaver will leave that tree and go on another. If all the trees around the pond become too large for the beaver’s “internal clock,” it abandons the pond. Without harvesting pressure from the beaver, saplings begin to grow and thrive. Once again making for an ideal home for the beaver.

While the beaver pond mentioned at the outset is not accessible by the trail system of Chicopee Woods, the careful observer should be able to see evidence of beaver activity in, and around Chicopee Lake.