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January 2021 Newsletter

Happy New Year!

We hope you enjoyed a safe and healthy holiday season. We are excited to start the new year as we explore options for providing new and innovative learning opportunities in 2021. Water Center staff has connected virtually with our community through several captivating videos and many fun and educational social media posts. Discover videos and other environmental facts on our Online Community Learning Page or through Facebook and Instagram.

Please continue to stay connected, especially as we support one another during these unprecedented times. We appreciate your continued patience and are always available at [email protected] if you have questions or comments. #StaySafe #StayHealthy #StayStrongVancouverWA

Beaver: Nature’s Builders - by Suzanne Hebert, Water Center Educator

The North American Beaver (Castor canadensis) is an iconic species on our landscape, often leaving signs of their presence without being seen. These shy aquatic mammals are the largest native rodent on the continent and play a pivitol role in maintaining the health of riparian ecosystems found along the shores of rivers, streams and lakes. Their story is one of resilience and renewed appreciation.

Prior to European colonization, North America was home to an estimated 60-400 million beaver. Abundant and thriving, they lived in balanced partnership with indigenous tribes while building habitat that supported fish, amphibians, reptiles and insects.

However, by the early 1900s European fur trapping enterprises like those based at Fort Vancouver, had hunted beaver to near extinction. Beaver pelts were primarily manufactured into fashionable felted hats. At the time, trappers and explorers didn’t seek to understand that beaver are a keystone species and removing them from the landscape imposes significant impacts on the composition of plants and animals in the environment. In fact, overhunting of beaver contributed to the degradation of salmon habitat and is considered the first human-caused impact on salmon. Fortunately, beavers are making a slow comeback with rough population estimates ranging from 6-12 million. Over the past 100 years, much has been learned about beavers and the benefits they bring to the land, wildlife and people.

Beavers are nature’s builders—true ecosystem engineers. They actively modify and manage the natural environment to maintain their preferred habitat which requires ponds of slow-moving water. To achieve this, many beaver build dams in rivers or streams to create ponds where lodges or bank dens with hidden underwater entrances are constructed. They also dig Beaver Dam canal systems that provide safe passage (USFWS National Digital Library) between feeding sites. Beaver themselves are slow moving on land, preferring to spend most of their time in water where they are less vulnerable to predators like coyote, mountain lions and bears. If danger is near, they warn family members using their distinctive flat tail to slap the water. Beavers use their nimble, hand-like front paws to dig canals and build their dams and lodges using mud, wood, stones and leaves. Lodges Beaver Lodge include hollowed out chambers located (USFWS National Digital Library) above the water line where beavers sleep, eat, groom and care for their young. Beaver families consist of a monogamous breeding pair, yearlings and kits-of-the-year. Kits usually stay with the family for two years before moving on to establish their own territory and family.

Beavers are choosy herbivores. They can eat a wide variety of plants, but have their favorites. In the Pacific Northwest they are partial to willow, cottonwood and alder. They’ll eat the leaves, twigs and cambium layer of trees and shrubs that grow near water. Their self-sharpening teeth grow continuously preventing them from wearing down despite chewing hardwoods. Once a tree is felled, beavers drag it to the water Beaver Chew Stump and use their canal system to float it back to the safety of their lodge or den to share with family or store away for a future meal. Beavers protect their food supply and territory from unrelated beavers by surrounding their ponds with scent mounds —piles of mud mixed with castoreum (concentrated form of urine) from members of the family. Over 100 scent mounds may be placed within a territory to deter potential invaders. Unfortunately, scent mounds failed to provide protection to Beaver Scent Mound beavers during the fur trade. Instead, their presence assisted trackers in locating beaver colonies.

The benefits of beaver activity extend far beyond creating safe habitat for beavers. As water slows and pools behind beaver dams, it spreads across the land expanding scarce riparian areas that provide up to 80% of wildlife with habitat at some point in their lives. Canals create braided and more complex habitat within the ecosystem. Beaver ponds trap nutrient-rich sediment Beavers create 'emerald refuges' creating fertile soils and act as water filters during wildfires (ESA Journals) that capture and prevent pollutants from travelling downstream. Ponds also create speed bumps against flooding by spreading out the water and slowing it down as it moves through the drainage area. This allows groundwater supplies to replenish and provides insulation from the effects of drought. Research has found that fish in streams with slow water habitat created by beaver are larger and more abundant than those in streams lacking slow water habitat. In Oregon, a study found beaver ponds represented only 9% of the habitat, but supported 66% of the coho salmon found in the system. Recent studies have also shown that beaver dammed areas of river valleys are less affected by wildfire and provide valuable emerald refuges for wildlife.

Beaver provide numerous benefits to ecosystems, but conflict with humans can still occur in both urban and rural environments. Fortunately many organizations are working with landowners to facilitate a peaceful and productive coexistence between beavers and people. Seeking to learn more about beavers in the last 100 years has sparked renewed appreciation for them, and choosing to engage with beavers as partners creates enormous potential for improving water quality, habitats and entire ecosystems that humans and wildlife can benefit from now and into the future.

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