Here’s a weird fact: Every time someone buys an assault weapon in the US, such as an AR-15, they’re funding wildlife conservation. The same is true if they purchase a handgun, a shotgun, or any other kind of gun or ammunition.

That’s thanks to a law most people have never heard of: the Federal Aid in Wildlife Restoration Act, commonly known as the Pittman-Robertson Act. Passed by Congress in 1937, the law channels revenue from a tax on firearms, ammo, and archery equipment to state wildlife agencies — government organizations that restore wildlife habitat, monitor threatened species, and oversee hunting and fishing. Levied on firearm manufacturers and importers, the tax is 11 percent for long guns and ammunition and 10 percent for handguns, and it sits on top of other common taxes.

Over the last decade, the law has channeled close to $1 billion a year into state wildlife agencies across the country, amounting to a substantial share of their budgets. One recent analysis found that Pittman-Robertson made up about 18 percent of state agency budgets, on average, in 2019. (License fees for fishing and hunting, along with a hodgepodge of other revenue streams, including a similar tax on fishing gear, make up the rest.) And revenue from Pittman-Robertson has been increasing, roughly doubling in the past two decades — in no small part because gun sales have surged.

Despite the dedicated tax revenue, wildlife agencies are still chronically underfunded. They oversee the bulk of the nation’s imperiled species — which now comprise more than one-third of all plants and animals in the US — and threats to biodiversity like climate change are only getting worse. These agencies need all the money they can get.

As a result, “wildlife agencies have a clear incentive to increase firearm use if they want to sustain themselves,” said John Casellas Connors, a researcher at Texas A&M University and one of the leading experts on the Pittman-Robertson Act. “There’s a desire to increase access to opportunities to shoot, to ensure that people keep buying guns and using guns.” Indeed, the purchase of firearms of any kind helps pay for staff, wildlife monitoring, and many of the other conservation tasks they do.

This raises an important question: Is it okay to fund conservation with tools of violence?

The link between conservation and guns is as old as the modern conservation movement itself. For a long time hunters were the movement.

In the late 1800s, elite and influential sportsmen like Theodore Roosevelt raised concerns about vanishing wildlife — deer, elk, bison, waterfowl, and other game species they liked to hunt. Ironically, rampant, unregulated hunting for profit is what threatened these animals in the first place. Around the turn of the 20th century, for example, market hunting drove now-abundant white-tailed deer populations close to extinction, and similarly eliminated all but a few hundred bison.

As much as Roosevelt and his peers recognized hunting as a problem for wildlife, however, they also saw sportsmen as conservation champions.

“In a civilized and cultivated country, wild animals only continue to exist at all when preserved by sportsmen,” Roosevelt said. “The genuine sportsman is by all odds the most important factor in keeping the larger and more valuable wild creatures from total extermination.”

That sentiment gave rise to the conservation movement that we know today — and to state wildlife agencies, most of which first appeared in the late 1800s and early 1900s. Staffed with biologists and ecologists, these government divisions sought to preserve habitat and regulate fishing and hunting, a remit still reflected in many of their names (Arizona Game and Fish, California Department of Fish and Wildlife, Pennsylvania Game Commission, and so on).

But they needed money.

That’s where Pittman-Robertson came in. The idea behind the law — named for its two Congressional sponsors, hunters Key Pittman and Absalom Willis Robertson — redirected an existing excise tax on certain firearms (and later, through amendments, all firearms) to state wildlife agencies. The law also prohibited states from redirecting revenue from selling hunting licenses away from those agencies.

The law put into practice what’s known as a “user-pay” model of conservation, the idea being that hunters rely on wildlife, so they should pay to preserve it — in this case through revenue from their hunting licenses and weapons. It also fueled the now-pervasive idea, perpetuated by hunters, that they pay for conservation.

That was largely true for a time, but over the last few decades the number of hunters in the US has slowly declined — from more than 14 million hunters who are 16 years and older in 1991 to fewer than 11.5 million in 2016. The share of people in that age range who hunt has fallen even more, from 7.4 percent to 4.5 percent over that same period.

This trend has been worrying for wildlife agencies precisely because they have relied so much on hunters for funding.

But here’s the thing: While hunters have declined, gun sales in the US have increased — dramatically so. Estimates from the Trace, a newsroom that reports on gun violence, indicates that gun sales have roughly doubled since 2000. That means people are buying more guns but for purposes unrelated to hunting, such as handguns and AR-style weapons for self defense or for use at shooting ranges. Indeed, more than 70 percent of firearm and ammo sales these days are intended for purposes other than hunting, according to a 2021 report from the market research firm Southwick Associates.

This has funneled more money overall to state wildlife agencies — just not from hunters. “The money that is going toward this largely is being borne by people who may never, ever step into the field, may never go into a duck blind, may never go out to a hunting stand,” said Mark Oliva, managing director of public affairs at the National Shooting Sports Foundation, a trade group for the firearms industry. And that, in turn, has prompted wildlife agencies to cater to this growing population of firearm users.

State wildlife agencies generally have two main goals: to manage hunting and fishing programs and to conserve native species and their habitats. That often entails things like removing invasive species, reintroducing animals back into the environment, and studying the spread of zoonotic diseases. Bringing wolves back to Colorado, for example, was a project led by the state’s wildlife agency, Colorado Parks and Wildlife.

But because of Pittman-Robertson and the ever-present crunch for funding, these organizations have become incentivized to encourage more gun and ammo purchases. Along with a handful of more recent amendments to the law — which make it easier to spend Pittman-Robertson funds on shooting activities — that incentive has led wildlife agencies to increasingly fund or build their own public shooting and archery ranges. Pittman-Robertson funding has supported more than 120 new ranges since 2019.

By promoting firearm use (and related ammo purchases), target ranges do indirectly support wildlife conservation. But they are of course not wildlife conservation, said Christopher Rea, a sociologist at Brown University, who’s studied Pittman-Robertson. This is an important point, considering the speed at which ecosystems and animal species are declining across the US — and considering that agencies are supposed to use their resources to stem such losses.

“Pittman-Robertson has drifted from preserving the biotic community and moved instead towards preserving firearms use,” Rea and Casellas Connors, of Texas A&M, wrote in a 2022 paper.

Some environmental groups have argued that, by using their limited resources to support sport shooting, wildlife agencies are pulling back on their responsibility to safeguard native species. “During a global extinction crisis requiring an all-hands-on-deck effort to conserve and protect declining species, state agencies are instead abusing the nation’s largest pot of restoration funding to promote recreational gun use and other ‘shooting sports,’” the advocacy group Wildlife for All said in a post on its website.

Wildlife for All estimates that about a quarter of Pittman-Robertson funding for state agencies goes towards shooting and archery ranges, hunter education, and promoting shooting sports. But still, the group found, most of that money is spent on wildlife restoration and projects to safeguard animals and their habitats. And barring a resurgence in hunting, promoting other uses of firearms is a way for wildlife agencies to maintain as much funding as possible for increasingly essential conservation projects.

There is, however, a deeper concern about funding conservation with firearms, though it has more to do with the human animal. Casellas Connors, Rea, and many other researchers point out that guns and gun ownership rates are linked to a higher risk of homicides and suicide. That means conservation is also tied to violence and harm.

“As a matter of my own personal politics and moral preferences, I don’t think we should be funding conservation by selling [what are] essentially tools of violence,” Rea, of Brown, told me. “That’s really problematic.”

Oliva, with the firearms trade group, strongly disagrees with the idea that more firearms means more violence. National crime rates have fallen substantially, he said, relative to the late 1900s. The number of gun deaths has declined in the last few years, too, even though there are more guns in the US than ever. (One major caveat here is that gun deaths are still well above pre-pandemic levels, and suicide-related gun deaths have continued to increase.)

Gun laws are, of course, among the most contentious topics in US politics, and it’s unlikely that questions about funding wildlife agencies will change opinions on either side. But even if you think promoting or benefiting from the purchase of guns is morally wrong, it’s hard to argue that — under the existing budgetary circumstances — losing nearly a fifth of funding wouldn’t decimate wildlife agencies’ work. There’s no getting around the fact that any laws that have the effect of meaningfully reducing firearms sales would also likely eat into critical funding for conservation.

Proposals to repeal Pittman-Robertson have been floated before, most recently in 2022. That would be a disaster for wildlife, said Mark Duda, executive director of the outdoor market research firm Responsive Management and a former state biologist in Florida. Money made available by the law has helped bring back all kinds of once-rare species across the country, he said, from elk and turkeys to peregrine falcons and bald eagles. In Montana, for example, the state agency — Fish, Wildlife, and Parks — used funding from Pittman-Robertson to study and later bring back bighorn sheep.

Other people I spoke to agreed. “Wildlife agencies probably wouldn’t have been able to do almost any of the work they’ve done without Pittman-Robertson funds,” said Casellas Connors, of Texas A&M, who’s currently working on a book about the law. Even with that funding, they often don’t have enough staff or resources they need to adequately monitor and restore declining wildlife populations, he said.

Jonah Evans, who oversees non-game and rare species at Texas Parks and Wildlife, the state’s wildlife agency, said that money from gun taxes funds staff salaries and research on a range of imperiled native species, such as the tricolored bat and the loggerhead shrike, a songbird. “Pittman Robertson is like the backbone of wildlife management at our agency,” Evans said. In Texas alone, there are more than 1,000 animal species in decline that need help. Trying to conserve them all with the limited resources that Parks and Wildlife has, Evans said, “is an overwhelming project.”

Disentangling the firearm industry from conservation could also have other, less obvious consequences. Beyond funding state agencies, Pittman-Robertson has also helped build a diverse political coalition of support for conservation, Rea says. The firearm industry — which tends to be much more conservative than the broader environmental movement — strongly supports Pittman-Robertson, in part because it helps sustain the animals that hunters want to shoot. And, by extension, the law gives the industry’s right-oriented constituency a stake in conservation. Even sport shooters and gun owners who don’t hunt support the excise tax, Duda told me, citing survey data.

“At a time when environmentalism is evermore polarized and left-coded, Pittman-Robertson helps continually reinject pro-conservation rhetoric into a right-leaning political sphere, via its links to hunting and guns,” Rea told me. “I strongly believe it’s one mechanism that helps maintain that long history of bipartisan support for conservation.”

The moral debate aside, most people agree that wildlife agencies need more money than they have now, even with Pittman-Robertson in place. And, over the years, lawmakers have proposed additional sources.

In 2022, the US House passed a non-partisan bill called Recovering America’s Wildlife Act, which would send $1.3 billion a year to agencies specifically to help them safeguard vulnerable species. But the bill never passed the Senate, because lawmakers couldn’t agree on how to pay for it. (For scale, the war against Iran has so far cost the US about $25 billion.)

Another idea that’s circulated for decades now is to place an excise tax on outdoor gear like backpacks and hiking boots that would, like Pittman-Robertson, go towards state agencies. The logic of a so-called backpack tax follows a similar “user-pay” model: Hikers, rock climbers, and birdwatchers are also using the outdoors, so they should pay in some way to protect it. And while hunting is declining, these outdoor activities are booming.

Nonetheless, the outdoor gear industry has successfully fought against putting such a law into practice, Rea said. “That’s really disappointing,” he told Vox. “That’s a way we could solve this problem.”

I asked the Outdoor Industry Association, a trade group, about this. Kent Ebersole, OIA’s president, told me that the group opposes a backpack tax, because it would make gear more expensive and, thus, make outdoor recreation less accessible. “You’re harming people by increasing the price of an already expensive product,” he said, adding that outdoor companies are already facing steep costs of production from tariffs. ‘We do care about conservation,” Ebersole said. There are other ways to fund conservation besides burdening the industry with another tax, he said. (Ebersole highlighted a law in Georgia that directs a large portion of existing sales tax on outdoor gear to state wildlife conservation.)

Wildlife conservation is one of the rare causes that people seem to value across the political spectrum. “I’ve done 1,200 studies on how people relate to wildlife, and that is the common denominator,” Duda said. “People care deeply.” And yet, somehow, it’s hard to get anyone but the gun industry to pay for it.