Chattanooga beavers are especially eager this year to acquire building materials for their dams from Ross's Landing, where the city's Parks and Outdoors Department is taking unusual measures to manage the damage to the trees along the riverfront.
The parks team recently planted new trees along the riverfront at Ross's Landing, and team members chose to plant bald cypress trees because beavers usually leave those alone. But the trees repeatedly were being damaged or taken down completely, sometimes within 24 hours of planting, city of Chattanooga Parks and Outdoors Communications and Marketing Director Brian Smith said in an email.
The beavers' chewing can damage or kill the trees and cause them to fall onto the nearby playground and path, making them a safety hazard, he said.
The parks team tried several methods to deter the beavers from gnawing on the trees. Team members put fences around them, but the beavers climbed the fences and continued to chew. Then they put hot sauce on the trees, which kept the beavers from chewing them, but the sauce washed off in the rain.
Park staff cannot trap and relocate the beavers, because according to state law, beavers must be euthanized if trapped, Smith said.
The best solution they settled on -- which is recommended by the Humane Society of the United States -- was to paint the trees using nontoxic interior latex paint diluted with water and mixed with sand, which irritates the beavers' teeth enough to encourage them to look elsewhere for a snack.
"This is the first year we have seen beavers in this area repeatedly," Smith said, adding that since staff members don't know where the beavers are taking the trees, it's difficult to say whether the area has a large beaver population. "Our parks team believes that due to the small size of the trees, this may have attracted them."
But beaver chew marks also have been spotted on other, older trees in Ross's Landing as well as in the nearby plaza surrounding the Tennessee Aquarium.
"What is also a curious trend is chewing patterns noted on magnolia trees, shrubs and redbud trees, which is unusual," Smith said.
Staff members think the beavers may be chewing more aggressively to use the trees to build dams to impress potential mates during mating season.
Beavers also eat bark and twigs from trees, with a preference for maple, willow, alder and birch. They store branches under water near their lodges, according to the Tennessee Wildlife Resources Agency website.
Park staff observed light chew marks on some of the painted trees, so the new method appears to be deterring the beavers. It is the first time staff members have used the painting method, which can also be used by citizens experiencing problems with beaver damage, Smith said.
"Beavers are considered a keystone species, shaping our ecosystem by providing a wetland habitat for several native species when building their dams," Smith said of the importance of beavers. "We have seen damaged trees in other locations, which are part of the ecosystem, but in this case, these trees are close to the path and playground, and a more concentrated effort, thus we needed to act for the safety of our citizens."
DID YOU KNOW?
– Beavers' ears and nostrils close when the animals are in water.
– Beavers' upper incisors are bright orange and continue to grow throughout the animals' lives.
– Beavers have flat, scaly tails that serve as rudders when they are swimming and as warning devices when slapped on the water. Their tails are also used for support when standing on land or dragging logs.
– Male and female beavers are thought to be paired for life. They begin mating in January and February. Gestation is around three months, and kits are born fully furred, with eyes open, and are able to swim right away.
– Beavers typically have two to four kits per litter. Parental care begins at birth and continues until young have reached self reliance, usually at 1-2 years old.
– Average beaver colonies consist of six or seven animals, usually including parents and their kits of two age classes.
– The beaver is the largest rodent in North America.
– Beavers are primarily nocturnal, although they may sometimes be seen during the day.
Source: Tennessee Wildlife Resources Agency