Tuesday, February 20, 2024

NOTES FROM THE FALLEN TREE: Many Ecosystems Depend on North America’s Largest Rodent – The American Beaver (Castor canadensis)

The American beaver (Castor canadensis). Photo by W. Kruegel.

An animal that many people are surprised to learn is in our area is the beaver, which is the largest rodent in North America. 

A distinguishing characteristic of rodents is that their teeth, or incisors to be more specific, grow throughout their entire life. In order to prevent their teeth from impeding their ability to eat, they must file their teeth down by gnawing on objects like wood. It doesn’t hurt that their preferred food is the fleshy cambium layer under the bark of trees. 

The tail of a beaver is significant as it can provide several uses. One, it stores fat for the cold winter months during which the beaver is still active. Two, it alerts family members to predators by slapping its tail on the water, making a loud sound. Three, the tail is used for balance while felling a tree. Fourth and finally, as a paddle when swimming in the water, where the beaver can hold its breath for up to 15 minutes. 

The beaver does not use its tail to pat down mud on the dams it is compelled to make. The dam is meant to drastically change the habitat from a moving body of water to a pond where they will build a lodge in the center with underwater entrances. It is the sound of running water that drives the beaver to create dams and stop the flow. 

This provides new habitats for snakes, birds, salamanders and other wildlife species. This makes the beaver a “keystone species” or, according to the Oxford English Dictionary, “a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.”

The only other mammals that will change their environment in order to live in it are humans. Beavers can be a pest in some areas as they create flooding where humans also reside but I’m sure the beavers would say the same about humans.

Jennifer Correa-Kruegel, Warren County Naturalist
Jennifer Correa-Kruegel, Warren County Naturalist

Jennifer has a Masters in Parks and Resource Management from Slippery Rock University. She worked as a Park Naturalist for Hunterdon County Park System from 2003-2006 and then at the NJSOC full-time from 2006 - 2020, starting as the Program Coordinator and evolving to an Environmental Educator. Jen is a New Jersey native and has lived in Warren County with her family since 2004. She is excited to be offering programs to this community she has grown to love.