Wetland Wonders : The Beaver Effect

By: Jordan Zapata

Beavers (Castor canadensis) may seem unassuming, but they play an outsized role in their environments. They’re considered ecosystem engineers. They change the environment to suit their needs. By doing so, they support our goals of restoring native species here at the Rosewood Nature Study Area.

Beavers are a semi-aquatic mammals native to much of North America, including Nevada. They are the largest rodent native to North America. Once abundant throughout its range, the beaver was nearly driven to extinction due to the fur trade. In fact, when biological surveys were conducted in the Sierra Nevada’s in the early 1900s, the species was already missing. Fortunately, regulations and reintroduction efforts have brought the species back to much of its original range. The beaver present at the Rosewood Nature Study Area is likely a result of these conservation efforts.

If you’ve been out to our wetlands recently, you may have noticed more water is staying on the landscape. While water level fluctuation in the streams and ponds throughout the seasons is normal, the higher water levels may be thanks to a beaver making a home here and building a dam. 

While many believe that beavers build dams to be their shelter, they don’t live in the dams. They build separate lodges to live in. They weave together rushes, cattails and sticks for another reason; protection. By holding back the water and creating a small pond behind the dam, the beaver is safe from predators that can’t swim well. Just the sound of running water is enough to trigger the beaver’s dam building instincts. 

The beaver will then build its lodge in the pond, which is accessible only to the beaver because the entrances are underwater. Besides living there and raising their young, they also store food and are kept warm through the winter in their lodge.

How does all this water affect the wetland? By building the dam, the beaver slows the flow of a river or stream, allowing the water to spread across the landscape. This gives it time to soak into the ground. By keeping water in the wetland, the risk of flooding in residential and developed areas is reduced. Slower water also means that minerals and nutrients have time to settle to the bottom, increasing water clarity and quality. Even more remarkable is that the ponds provide habitat for insects, amphibians, fish and aquatic plants. In fact, researchers have found that beaver dams support populations of Lahontan cutthroat trout in Crowley Creek, north of Winnemucca. 

Beavers are doing their part to increase the health of our ecosystem. Next time you’re out for a walk in the wetlands, make sure to observe all the ways beavers are affecting the landscape.

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About the Author

Jordan Zapata

Wetland Restoration Technician 

Born and raised in the great state of Michigan, Jordan  graduated with a bachelors in Plant Biology from Michigan State University in the spring of 2024. After working as a botanist for the Michigan Natural Features Inventory, he came to Reno to gain experience in ecologicalrestoration. He is  now serving as a restoration technician and is excited to use his experience in wetland restoration and working with native plants to further restoration efforts here atRosewood! Outside of work, Jordan enjoys hiking, biking and IDing new plants on INaturalist.