Over the years, humans have had a profound effect on biodiversity. Whether through population, land use, exploitation or lifestyle, everywhere people go, they have an impact on the environment and ecosystem services that we all rely on.
This pattern is exemplified by the beaver and its extirpation (local extinction) in the northeastern part of the country, a result of the fur trade industry between roughly 1600-1900. European demand for mammal pelts, such as the beaver, altered life for Indigenous North Americans and shifted thousands of years of traditional harvest practices.
While existing research has given us some insight, scientists hope the eager beaver and its furry cohorts will improve our understanding of the past, and better manage current and future conservation efforts for these furbearers.
Courtney Hofman, President’s Associates Presidential Professor in the Department of Anthropology, Dodge Family College of Arts and Sciences at the University of Oklahoma, is leading a project studying how human management schemes and Indigenous relationships influenced furbearers, specifically beaver, mink and muskrat.
Hofman’s work is the focus of a $1.5 million grant from the National Science Foundation. The four-year study uses ancient DNA samples derived from archaeological specimens housed at the Smithsonian Institute’s Natural History Museum and among other museums, as well as samples from modern beaver, mink and muskrat provided by wildlife managers and fur-trappers, to better understand the relationship between people and these animals. The study incorporates a diverse group of collaborators, including the Smithsonian, Middlebury College, the University of Maine and tribal partners.
“Interestingly, despite those species being really important commercially, like fur farms, there really hasn’t been much genetic study at all of their native ranges in North America,” Hofman said. “Especially with something like the beaver that almost went extinct due to overharvest and is now recovering, there is a lot of potential to estimate how many beavers were on the landscape in the past – before euro-colonial harvest – and explore questions of how ecosystems have changed due to human action and human behavior over the last several thousand years.”
Hofman said shifting baselines – the idea that as resources decline, each new generation accepts that what the previous generation experienced was normal – often make it hard to determine what should be considered normal in the area of ecological restoration. By extracting DNA from archaeological and historic specimens, scientists can get closer to the truth.
“We can use the archaeological record as a time machine to go back and see how much genetic diversity has been lost due to the fur trade and then think about how that impacts the management of these species today,” she said.
Hofman hopes working with wildlife managers will help guide future conservation efforts. Beaver managers with whom she works in Maine are interested in what the beaver landscape used to be and what it could support. By partnering with fur trappers, she and other researchers hope to collect tissue samples that will help paint an accurate picture and guide current fur trappers.
“There’s a difference between the environmental carrying capacity, or how many beavers can be maintained in the environment, and the cultural carrying capacity, or how many beavers people think or want to be there because they can mess up their fields or do things that are destructive to their landscapes or farms,” Hofman said. “Having an estimate of what was there can guide them a little bit as they manage fur trapping, which is still an important activity today. It provides information on what was, so we can think about what could be.”
As part of this research, Hofman is also studying what the extinct sea mink can tell her about the fur trade and the modern mink.
“Sea mink, now extinct, lived on the coast of Maine. It was larger and probably smellier than the American mink. It went extinct in the late 1800s, probably due to overharvesting,” she said. “The larger sea mink was more attractive because for the same amount of effort you could get a bigger skin to sell.”
Hofman said most of what we know about sea mink is from the archaeological record. There’s not much other information available except in museums.
“We have been sequencing the DNA of extinct sea mink to figure out what this extinct species was and how it relates to the modern mink that live in North America today,” she said. “But there’s a shifting baselines question here because the sea mink went extinct and on the coastal islands where it used to live there’s a great interest in protecting sea birds and nesting sea birds. Closely related American mink from the mainland have been swimming out to these islands and predating on the sea birds living on the islands. Right now, managers are removing mink when they find them on these islands to protect the birds. But there used to be sea mink that lived on these islands that went extinct before our recent memory. Perhaps the sea birds on these islands, instead of being in decline, are fluctuating to population levels when the sea mink existed on the landscape.”
Sara Williams, a University of Oklahoma dual major in human health and biology as well as microbiology, and Elizabeth Austin, an environmental science and earth and climate science major at Middlebury College in Vermont, spent time interning at the Smithsonian’s Natural History Museum, where they helped identify specimens for use in Hofman’s project, including the sea mink. They blogged about the experience before presenting their internship findings at the Furbearer’s Conference at Shoals Marine Lab in Maine, organized by Hofman and project co-investigator Alexis Mychajliw. This workshop brought together wildlife managers, fur trappers, archaeologists and Indigenous community members to help direct future research.
Not only does the study detail the effect of the classic Euro-American fur trade on beaver, mink and muskrat, it also delves into the historical exploitation of Indigenous peoples.
This past June, Hofman and Mychajliw attended an archaeological field school led by Bonnie Newsom, a Penobscot Nation citizen, assistant professor at the University of Maine and senior personnel on the project. Newsom has done extensive work on Indigenous archaeological methods, utilizing language experts in her workshops to connect objects to the language.
“We’re using archaeological material from Wabanaki ancestors, so we want to make sure this project is inclusive of the people who lived on these landscapes and continue to live on these landscapes and seascapes,” Hofman said. “We’re looking at the human influence on the furbearers as part of this project, so making sure that those communities are represented is incredibly important.”