Last Resort: Moving Endangered Species in Order to Save Them

At the identical time, people have purposefully or by accident introduced invasive species to habitats all over the world. The brown tree snake, which devoured Guam rails, together with other native birds, lizards, and bats, is a classic example.

Now climate change is further altering the habitats of the world’s species —warming lakes and oceans, transforming forests to grassland and tundra to woodland, and sending glaciers flooding into the ocean. This spring, the Intergovernmental Panel on Climate Change released a report estimating that as much as 14 percent of the tens of hundreds of terrestrial species in its assessment could face extinction if the world warms 1.5 degrees Celsius above pre-industrial levels, which it’s now on course to do.

In response to those changes, lifeforms are rearranging themselves, migrating to follow shifting conditions. But many species, especially people who have already lost much of their habitat, just like the Guam rail, may have human help to achieve places where they’ll survive.

Currently, the U.S. Fish and Wildlife Service — which, together with the National Marine Fisheries Service, enforces the Endangered Species Act — rarely moves threatened and endangered species beyond where they’re known to have occurred previously, because it did with the Guam rail. Its regulations allow it to ascertain “experimental populations” of species only of their “probable historic range,” except in extreme cases.

Recently, though, Fish and Wildlife proposed a revision to its regulations that may allow it to maneuver species beyond their historical range, calling this a “obligatory and appropriate” step in response to the dual threats of climate change and invasive species. With increasing numbers of species prone to extinction, says Tim Male, founding father of the nonprofit Environmental Policy Innovation Center, “we may have this tool rather a lot more often.”

The power to maneuver species beyond their historical range can be a small change on paper, but one which each supporters and opponents of the revision say could significantly impact American conservation.

When Congress passed the Endangered Species Act in 1973, it gave the National Marine Fisheries Service and the Fish and Wildlife Service the power to maneuver species from one place to a different, a practice called “translocation.”

“The agency knew for species just like the bald eagle, they were going to must translocate individuals from Alaska to the Lower 48, where it had been extirpated in lots of locations,” says Patrick Shirey, an environmental scientist and legal scholar on the University of Pittsburgh. “Congress gave the express authority for translocation.”

It further clarified this authority in a 1982 revision to the Endangered Species Act, giving the wildlife agencies the power to create “experimental populations” of listed animals and plants. While Congress offered no limits on where the agencies might establish experimental populations, stipulating only that they have to be physically separate from “non-experimental,” or wild, populations of the identical species, Fish and Wildlife provided limits of its own. In regulations it adopted in 1984, the agency restricted itself to establishing experimental populations only inside a species’ “probable historic range.”

“Historic range” was each ill-defined and Eurocentric, in a rustic where written records extend back lower than six centuries, but where human history — and ecological impact — extends back tens of hundreds of years. It also took a static view of the living world, seeming to assume that the past range of a species represents that species’ ideal range. This view was at odds with the fossil record, which showed that the arrangement of species is continually in flux, especially during times of climatic change. It was also increasingly at odds with the fact of climate change in the current.

Since at the very least the Eighties, scientists have debated the merits of a really specific variety of translocation called “assisted migration” (and sometimes “assisted colonization” or “managed translocation”), which goals to conserve species by moving them to climatically suitable places outside of the range that they currently or recently occupied. Some scientists argued that habitat destruction would make it inconceivable for a lot of species to maintain up with the pace of climate change, and that without human help those species could face extinction. Others, pointing to the destruction wrought by invasive species, maintained that moving species to latest habitats as a conservation method was too dangerous.

Many years later, despite a whole bunch of educational papers and countless media reports on the subject, though, there are relatively few real-world experiments in assisted migration. Scientists have moved butterflies, lichens, and rock lobsters, together with a handful of other creatures. A bunch of personal residents planted the endangered Florida Torreya, an evergreen within the yew family that’s native to riparian areas in Florida and Georgia, far to the north, throughout the eastern United States. Plenty of timber corporations, state and federal forestry agencies, and tribes within the U.S. and Canada have moved trees, most of them common species.

The Fish and Wildlife Service’s regulations appear to offer for the potential of assisted migration experiments. In “extreme” cases where the agency’s director determines that a species’ critical habitat has been “irreversibly altered or destroyed,” the agency may establish an experimental population outside of the species’ historical range. The agency relied on this exception to maneuver the Guam rail to Rota.

“That’s pretty clearly unsuitable and irreversible,” Shirey, of the University of Pittsburgh, says, speaking of the rail’s habitat in Guam. “A nonnative, invasive predator that eats all the things, and a bird that may’t fly away.”

But few cases are so clearcut or so legally defensible. In a 2010 paper with Gary Lamberti, an ecologist on the University of Notre Dame, Shirey argued that while this exception looked as if it would allow for assisted migration experiments of rare, endangered species, normally it might be too difficult to prove that a species’ habitat is irreversibly altered or damaged, or that its situation was “extreme.” Because the biodiversity crisis progresses, the barrier for designating cases as extreme is getting higher. Fish and Wildlife spokesperson Karen Armstrong noted that it’s increasingly routine for climate change and invasive species to threaten species’ habitat. “These are not any longer ‘extreme cases,’” she wrote.

In 2018, Fish and Wildlife began to contemplate changing its regulations, and this past June it published its proposal to remove the words “historical range” from its regulations on experimental populations.

The proposed rule drew greater than 500 comments. Many were critical of the proposed changes, calling them unnecessary or misguided, suggesting that they might allow the service to release endangered species — and the laws and regulations they bring about — nearly anywhere within the country.

Some were concerned concerning the possible reintroduction of wolves and other predators, noting that the wolves that Fish and Wildlife reintroduced into Yellowstone and parts of the Southwest within the Nineteen Nineties have killed ranchers’ cattle and sheep. Other commenters echoed longstanding arguments against using assisted migration, suggesting that translocating creatures carried an excessive amount of risk of unintended consequences.

Ben Novak, lead scientist at Revive & Restore, a nonprofit focused on using cloning, gene editing, and other genetic technologies in conservation, says that fears that latest experimental populations might turn into invaders are overblown. While translocated species have caused ecological disasters — as when people brought cane toads from Hawaii to Australia, for instance, or introduced Indian mongooses to the West Indies — nearly all of those species were translocated for economic or cultural reasons, not as a part of conservation efforts, Novak says.

Last 12 months, Novak and his colleagues published a paper analyzing the purposeful translocations of greater than 1,000 species within the U.S. over the past 125 years as a part of conservation efforts. They found just one conservation translocation — of a fish — that resulted within the loss of great biodiversity.

Within the late Eighties, Fish and Wildlife moved 200 endangered watercress darters from its native Black Warrior River drainage, near Birmingham, Alabama, into Tapawingo Springs, 15 miles northwest. But Tapawingo Springs, it turned out, was home to a different rare species, the push darter, which was only described as a species in 1998. By 2001, the now-thriving population of watercress darters had worn out the spring’s population of rush darters (although the species persists elsewhere). Such mistakes are rare, Novak says. “I actually think ecologists have a powerful history of creating predictions. We will do that well.”

In its proposal, Fish and Wildlife didn’t make an explicit connection between its proposed ability to ascertain experimental populations outside of species’ historical ranges and the decades-old debate over assisted migration. But evolutionary geneticists Janna Willoughby and Avril Harder did, in a comment they submitted to Fish and Wildlife with other members of the lab that Willoughby leads at Auburn University. The biodiversity crisis means regulators “need to significantly consider conservation actions which might be currently deemed too extreme,” Harder said. Willoughby agreed: “What we expect is extreme today could also be common in a reasonably short time period.”

Mark Schwartz, a conservation scientist at University of California, Davis who was an early skeptic of assisted migration, said that it’s hard to say exactly what effect Fish and Wildlife’s rule change can have on conservation efforts. On the one hand, he said, the relative dearth of assisted migration experiments could also be due less to the present legal barriers and more to a scarcity of scientific and societal consensus on the practice, making wildlife managers reluctant to make use of it. However, he said, “I do think the dearth of policy has hindered experimentation, in that it is usually not an option on the table due to a scarcity of policy that allows it.”

Schwartz was a part of a team that developed a risk-analysis framework for the National Park Service to make use of in considering potential assisted migration experiments, published last 12 months. He’s now working with the Fish and Wildlife Service’s Pacific Region subdivision to develop an analogous framework for that agency.

Gwen Iacona, a conservation scientist at Arizona State University, said that Fish and Wildlife’s proposed rule change is beneficial, but what would really make the Endangered Species Act more practical is more funding. “Lack of funding is way and away the largest limitation to ESA recovery,” she said. “The ESA has the potential — still — to do its job well, but we as a society have to provide it a probability by funding the actions that its implementation demands.”

Karen Armstrong, at Fish and Wildlife, said that the agency couldn’t say when it might publish a final version of the rule change, nor did it formulate the rule with any particular listed species in mind. But she did note that it recently proposed moving one other species outside of its historical range, citing extraordinary circumstances: the Guam kingfisher, or sihek.

The kingfisher is as boldly appointed because the Guam rail is unassuming. It has dark blue wings, an orange head and body, and a dark stripe over its eyes like an old-fashioned burglar’s mask. The kingfisher was driven to extinction within the wild by the brown tree snake and has continued for the reason that early Eighties only in zoo-run breeding programs. But these programs are at capability. To create space, and prepare for the day when Guam is rid of brown tree snakes, Fish and Wildlife plans to release a small population of kingfishers into the wild — not on Rota, but on Palmyra Atoll, 3,650 miles to Guam’s east.