The American Beaver: Nature’s Engineers!

by User Not Found | Feb 10, 2021

By Abigail Riehle, Elementary Education and History, ‘22

As I mentioned in my previous blog “How Do Animals Survive the Winter?,” the Nina Mason Pulliam Ecolab is home to a beaver colony. They make dams and clog up some of the drains in the Ecolab, which can be a challenge, but in doing so they create and maintain these highly diverse ecosystems. I have heard about the beavers during tours of the Ecolab, and wondered, what else do they do? Why do they make dams in the first place? 

First a general description: beavers are the largest rodent in North America. Adult beavers can be around four feet long and weigh 30 to 70 pounds. A beaver’s back feet are webbed for swimming. Another special feature of their hind feet is that the second toenail is split and used to groom their fur. 


This was an interesting feature found that I never heard of before! Beavers also have a flat tail. This tail is used for multiple purposes. It propels the beaver to swim faster and acts as a rudder. When a beaver is chewing a tree, the tail helps prop the body steadily on the ground. The tail is also a form of protection. A beaver will slap the water in order to warn others of a possible nearby predator. Not only does the beaver stay protected by warnings, but it can also submerge itself underwater and can remain submerged for up to six minutes! 

Beavers are known for making dams. They do this to maintain water levels in the wetlands they inhabit. A beaver’s home is called a lodge, and it can have multiple rooms to house the entire beaver family which consists of the parent, babies from this year, and babies from last year. The entrance is underwater, which would come in handy to escape from predators. The home is also warm due to the thickness of sticks and muds used to make the dam, which helps them keep warm during winter, since they do not hibernate. 

Beavers were once rare in Indiana. This was due to overharvesting most likely due to the popularity of their furs for clothing. 

beaver lodge_flickr

In 1935, a few pairs of beavers were brought in from Wisconsin to repopulate the state. Beavers can now be found in almost every county of Indiana. As a keystone species, beavers are important in helping to create and maintain important wetland habitat. These wetlands help almost half of the endangered and threatened species in North America! Their dams influence creek flow and create ponds. The ponds then become home for fish and other animals that rely on water and wetland habitats. The dams also help slow flood waters, which benefits us as well! Indiana has lost over 85% of its wetland habitats, so we need beavers to help maintain what is left and restore what has been damaged. Wetlands are highly diverse ecosystems that not only provide a home for many different types of wildlife, but also provide a lot of ecosystem services for us, such as flood control, water filtration, and groundwater recharge. 

If we do not care for the beavers, they may become rare once again. By keeping waterways clear of trash and toxic substances, and by protecting precious wetland habitats, we can help them and other wetland wildlife stay healthy. If you want to see some of their handiwork, come take a walk in the EcoLab! Their lodge is visible along the Jensen North Shore trail, and evidence of their presence is seen all around the pond and along Crooked Creek.

Beavers Belong! (2018, November 26). Retrieved November 11, 2020, from

Beaver. (n.d.). Retrieved November 08, 2020, from

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