Dam Beavers, for a more sustainable world

Abstract

Beavers are everywhere…but not literally though. In fact, they are nowhere nearly as ubiquitous compared to where they used to be. Estimates suggest that while as many as 400 million beavers (Castor canadensis) were present in North America prior to European colonialization, there are around 10 million now. In Europe, by the end of the 19th century, the total number of Eurasian beavers (Castor fiber) was estimated to be just 1200 individuals scattered across eight isolated populations. A recent estimate puts the Eurasian beaver population at 1.5 million individuals (Mamm Rev 2021).

The reintroduction of beaver populations represents a major conservation success. Although modern beaver populations remain a fraction of their historical numbers, due to centuries of trapping and habitat loss, their recovery can be attributed to a suite of factors including not only effective conservation and legal protections, habitat restoration, and conflict resolution strategies, but also increased public awareness. Their resurgence, juxtaposed with the near-extirpation of C canadensis and C fiber from North America and Europe, respectively, may contribute to the perception that beavers are now widespread. However, recognizing this recovery within the context of historical population baselines underscores the continuing need for conservation and habitat restoration efforts.

Human fascination with this cute, orange-toothed, semi-aquatic rodent is encapsulated in several successful popular press books including Eager: The surprising, secret life of beavers and why they matter (White River Junction, VT: Chelsea Green) by Ben Goldfarb; Beaverland: How one weird rodent made America (New York, NY: Twelve) by Leila Philip; and Bringing back the beaver: The story of one man's quest to rewild Britain's waterways (White River Junction, VT: Chelsea Green) by Derek Gow. And there is now among the public a growing recognition of the ecological roles beavers play across the landscape. As ecosystem engineers, they actively shape their environments by regulating water flow, enhancing landscape resilience to wildfire, and creating critical habitat for a diverse array of species. A review out of the University of Helsinki of the ecosystem services that beavers provide would put a value of about $900 per hectare per year where beavers are active (Mamm Rev 2021).

Our lab began studying beavers after a 15-meter-long dam appeared seemingly overnight in one of the University of Vermont's Natural Areas. While students celebrated the new habitat, reactions were mixed, prompting us to reroute a trail and install signage highlighting the ecological benefits of these ecosystem engineers. This event sparked a series of research initiatives examining the ecological and social dimensions of beaver activity. We analyzed water quality upstream and downstream of beaver dams to assess their role in nutrient retention, surveyed aquatic macroinvertebrate communities to evaluate species composition shifts, and conducted experimental surveys to compare the perceptions of beavers by landowners with those by the general public. Additionally, we employed qualitative coding techniques to analyze the text from American newspapers since 1691, tracing shifts in societal values toward beavers from utilitarian resource to luxury commodity, conservation priority, and nuisance species. Through this interdisciplinary approach, we gained insights into the ecological functions of beavers and their complex interactions with human communities.

We learned that beavers serve as an ideal model for examining the interconnectedness of socioeconomic and ecological systems, prompting us to adopt diverse methodologies to explore both natural and social science questions at the landscape scale. After studying beavers for over two years, we confirmed what many readers of Frontiers likely already appreciate: that beavers offer a powerful lens for investigating ecological processes, landscape dynamics, and species interactions. Their capacity to shape ecosystems makes them a valuable focal point for assessing ecosystem services; informing restoration efforts; and examining human–wildlife interactions, conflicts, and coexistence. Moreover, their near-extirpation and subsequent recovery, albeit with a dramatically shifted baseline, highlight the fluid nature of human value systems and the ways in which they evolve over time and across contexts.

Many species mirror these aspects of beavers, and could be a foil for teaching, research, and practice in conservation and ecology, but beavers are just super obvious on the landscape. They are charismatic, fun to watch, mischievous—and the costs and benefits of having them move into your neighborhoods are observable in mere days. It has been so rewarding to look at the landscape, our ecological networks, and our social systems through the lens of one, albeit incredibly charismatic, creature.

In our chaotic, rapidly changing, and often disheartening current climate, we have found that slowing down—by zooming in on and deeply engaging with a project you find fascinating—can be good medicine. In our often oversubscribed, resource-limited, and hectic lives as scientists and students such an inspiring focus, like Castor spp, can allow us, for at least for a short time each day or week, to ignore the hourly changing winds of our sociopolitical context and smile at the constantly changing natural world around us.