North American Beaver
(𝑪𝒂𝒔𝒕𝒐𝒓 𝒄𝒂𝒏𝒂𝒅𝒆𝒏𝒔𝒊𝒔)
Conservation Status: Least Concern (Population stable)

Photo Credit: Glacier NPS/Creative Commons

Facts: The beaver, at four feet long, is the largest rodent in North America. But they are so much more than that! Built for life in the water, you can find beaver in rivers, lakes and ponds. You might hear a tail slap, which is their way of warning about danger, or you might see the familiar dam and lodge which they build with the wood from the surrounding forest. They prefer the wood of deciduous trees and will cut them down in winter, leaving mainly conifers. This preference can transform the surrounding woods into a conifer dominating forest. Who knew one animal had so much influence!

This strong influence on the surrounding landscape is why the beaver is known as a keystone species. A keystone species is a species that has a great effect on the environment on which it lives. You may be familiar with the dams beaver build, but these structures can create new wetlands, help slow erosion, raise the water table and help purify water! They build lodges of sticks and mud and when they abandon them aquatic plants take over. Soils build up, making way for shrubs and other plants to grow and eventually become a meadow. Trees will grow and that meadow will then become a woodland area. However, beavers can also have a negative effect on the environment. Their dams can slow water movement through an area and destroy habitat for local species.

Something to think about: Ever wonder how a beaver spends so much time in the water, and yet can dry its fur so quickly? Beaver waterproof their fur by coating it with an oil called castoreum. Much like the river otter we posted previously, keeping their coats dry helps keep this creature warm in the cold waters.

Sources: https://nhpbs.org/natureworks/beaver.htm, https://www.nature.com/scitable/knowledge/library/keystone-species-15786127/, https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/castor-canadensis