In November, the U.S. Fish and Wildlife Service (USFWS) published a plan to cull nearly half a million barred owls across the lush old-growth forests of the Pacific Northwest and California. 

But by killing these owls, the agency is hoping to save owls—albeit a different species of the bird. Officials plan to remove a portion of the abundant barred owl population over a three-decade span to clear up space and resources for the threatened northern spotted owl, of which only around 4,000 remain on federal lands. Native to the region, spotted owls have faced a number of threats in the past few decades, including forest loss due to logging and competition with the barred owl, which has been more successful at hunting and adapting to a variety of territories than its vulnerable avian cousin. 

Scientists are still not certain how or where the barred owls came from, but research shows that they began to expand their range westward concurrently with European settlement and as human-caused changes altered habitats in the Great Plains and northern boreal forest. As a result, many say the barred owls are an invasive species and must be removed to protect native species, reports NPR. 

However, the USFWS culling plan has triggered a spate of backlash since it was announced; just last week dozens of wildlife organizations published a letter condemning this effort and arguing that it “betrays a willful failure to anticipate the wide range of adverse consequences such a plan will invariably unspool.” 

The plan has also resurfaced a longstanding debate over what makes a species “invasive,” and how nonnative plants and animals should be treated within an ecosystem. Today, I am diving into the details of the invasive debate, and how it could affect wildlife management moving forward. 

What’s in a Name? The author Charles Elton was the first to use the term “invasion” to describe foreign plants and wildlife in his 1958 book “The Ecology of Invasions by Animals and Plants,” reports The New York Times. 

Scientists have identified countless nonnative invasive species across the U.S.—from cane toads in Florida to fingernail-sized zebra mussels in the Great Lakes. In most cases, these species are introduced by humans who may accidentally carry them over on transit or intentionally release them. While many nonnative species are relatively harmless to an ecosystem, others can have catastrophic consequences; for example, feral pigs have destroyed crops and spread disease across at least 35 states in the U.S., according to the USDA. 

A 2021 study found that invasive species have cost North America more than $26 billion per year since 2010. Additionally, a growing body of research shows that climate impacts such as drought and fire could be creating ideal conditions for invasive species to thrive, or opening up new pathways for nonnative species to enter different ecosystems.

The U.N. has deemed invasive species as one of the five main drivers of global biodiversity loss. However, it’s important to note that these animals are biodiversity themselves, said Cebuan Bliss, a doctoral candidate at Radboud University in the Netherlands who studies animal and biodiversity governance. 

“The words we use determine what courses of action are deemed acceptable and appropriate,” Bliss told me over email. “When we call something invasive, we may show less regard for their welfare.” 

Bliss pointed to certain inhumane methods to kill nonnative species such as traps once used in the Netherlands to kill muskrats by holding them underwater until they drown. Other researchers have also questioned the term “invasive.”

“It’s not that it can’t be descriptively true at times, there can be nonnative species moving into an area, causing damage, which is emblematic of the meaning of invasion,” William Lynn, a researcher at Clark University in Massachusetts who studies animal and sustainability ethics, told me over the phone. “But to label species ‘invasive’ simply because they’re nonnative or they’re immigrant species, or to blindly bandy about the term ‘invasive’ species when it’s not clear that that’s what’s going on, is the problem.” 

The Owl Conundrum: The northern spotted owl is listed as threatened under the Endangered Species Act, meaning that the USFWS is legally required to protect it. This led the government to enact rules limiting the area that timber companies could log, sparking backlash from industry and residents in the region for its economic impacts. 

Now, the Service has deemed this cull a necessity in following through with this obligation. 

“Barred owl removal is not something the Service takes lightly,” Jodie Delavan, a public affairs officer with USFWS in Oregon, told the Guardian. “However, the Service has a legal and ethical responsibility to do all it can to recover northern spotted owl populations. Unless invasive barred owls are managed, the federally listed northern spotted owl will be extirpated in all or a significant portion of its range.”

The U.S. government has performed a barred owl culling experiment before, but at a much smaller scale than the new USFWS project. Over a decade ago, a team of researchers led by the U.S. Geological Survey killed more than 2,400 barred owls, and found that their efforts helped temporarily stabilize spotted owl populations over the next five years, according to a 2021 study.  

At that time, Lynn was a member of the government’s “Barred Owl Stakeholder Group,” which performed an ethics review before the project took place. 

Despite the groups’ “deep discomfort with killing barred owls,” they deemed it necessary to cull several thousand barred owls in order to save the spotted owl species, Lynn said. Overall, though, he said that the experiment “failed” because while it slowed the decline of the spotted owl, it did not act as a long-term solution.  

“It’s a very different situation now,” said Lynn, adding that he does not think this new cull will save the spotted owl. 

Wildlife managers have tackled other invasive species using a similar strategy, and even recruited the help of the public to control populations. In my home state of Pennsylvania, there was a widespread “stomp and smash” campaign in 2022 to kill invasive spotted lanternflies, complete with t-shirt merchandise. Currently, the Florida Fish and Wildlife Conservation Commission is asking individuals to hunt invasive Burmese pythons throughout the state after completing a training course. 

Lynn says nonnative species control should be determined on a “case by case basis,” and the main factors to consider are “effectiveness and ethics.” 

“There’s no reason to fall into a moral panic because a non damaging nonnative species is making a niche within a new ecology,” he said. “If you’re going to kill ‘invasive species’ with no prospect of real effect, then there’s not only the ethics of harming those individuals or those social groups in and of themselves, there’s also a question of doing so for no real beneficial purpose.”

More Top Climate News

On April 10, the Environmental Protection Agency (EPA) announced the country’s first-ever limits on “forever chemicals” known as PFAS, in drinking water. The ruling will require utilities to decrease perfluoroalkyl and polyfluoroalkyl substances to “the lowest level they can be reliably measured,” writes Michael Phyllis for the Associated Press. 

The Biden Administration says these limits will help protect 100 million people from PFAS exposure, which has been linked to immune system issues, developmental delays and breast cancer. But this won’t happen overnight; public water systems have three years to test six different types of PFAS and five years to decrease levels to the new standard. Some estimates suggest that installing technology to remove PFAS from the tap will cost up to $4 billion, writes Sara Novak for National Geographic.

“We’ve learned lessons over the past few decades that once these compounds get into our environment, they’re extremely difficult to remove,” Scott Belcher, director of the Center for Environmental and Health Effects of PFAS at North Carolina State University in Raleigh, told National Geographic. 

In other PFAS news, states are starting to require clothing companies to phase out forever chemicals, but that doesn’t solve the toxic substances lingering behind in secondhand clothing, reports Bloomberg. While buying pre-worn clothes can be a more sustainable option than purchasing new ones, experts worry about the long-term staying power of forever chemicals in legacy products. 

“Once it’s in the clothing, it’s really hard for us to tell or deal with it,” Yiliqi, a scientist and project manager at the environmental group Natural Resources Defense Council, who goes by one name, told Bloomberg. Yiliqi added that individuals should try not to buy new or used products that are known to have PFAS.