In Washington’s Cascade Range, warmer summers and rainy winters deprive Mount Rainier’s white-tailed ptarmigan of the alpine snow it depends on year-round. On the east coast, rising seas are engulfing the wetland habitat of the Salt-Pasher Sparrows. And on the Hawaiian Islands, forest birds like the ‘I‘The iwi are being driven upwards as warming temperatures allow mosquitoes – and the deadly avian malaria they carry – to spread to higher altitudes.
These and other at-risk birds, according to the US Fish and Wildlife Service (FWS), are helping to underscore the need for a proposed policy change that would allow wildlife managers to establish “test populations” of species. threatened or endangered in areas where they have never lived before. The Endangered Species Act (ESA) generally allows these introductions outside of where a species currently lives, but only within its historic range. But climate change is already forcing species to raise their stakes, according to the FWS, so the new policy would allow the agency to greenlight the introduction of listed species into new habitats.
“Recovering species and preventing their extinction will require innovative, proactive and science-based conservation policies and actions that address the growing impacts of climate change and invasive species before it is too late,” said said Martha Williams, director of the FWS, in a June 6 press release announcing the proposal. The agency will accept public comments until August 8 before drafting a final rule.
ESA scientists and experts tell Audubon that the proposed change would give wildlife managers the flexibility to preserve vulnerable species in a deepening climate crisis. “This is the type of bold thinking we really need to mitigate threats,” says Michael Scott, a retired conservation biologist from the University of Idaho. “It could become a major tool with climate change.”
The new policy would provide “a useful tool and a necessary tool,” says Patrick Parenteau, a professor at Vermont Law School, of the proposed change. “We have to do things that we have never done before to deal with climate threats, that we have never seen before.”
Others warn, however, that the plan could have unintended consequences for ecosystems. “I think it’s potentially disastrous,” says Daniel Simberloff, an ecologist at the University of Tennessee at Knoxville. He and his colleague Anthony Ricciardi, an invasion biologist at McGill University, have previously warned that introducing a species outside of its historical range – assisted colonization or assisted migration, as scientists often call it – poses many risks.
Introduced animals could compete with native animals for food, for example. If not quarantined appropriately, they could carry insects or pathogens hitchhiking through the ecosystem. “All you do is play green,” says Ricciardi. “You spin the roulette wheel enough times and you will have disasters.”
The introduction of red squirrels to Newfoundland is one example, Ricciardi says. Released in the 1960s as prey to boost the declining pine marten population, red squirrels have begun to compete with native red crossbills for black spruce seeds, threatening the survival of the bird. Native species like the Red Crossbill have evolved over millennia in their particular environments, making it difficult to fully understand how they might behave when a new animal is introduced, even after years of research and planning. thorough.
But taking such bets may be necessary on a rapidly warming planet, others argue. “The theme is one that is going to be important for many Endangered Species Act programs, and that is that climate change is transforming ecosystems in ways that could make areas outside the range current and even historical distribution of a species — and even areas that might not be currently occupiable — occupiable,” says JB Ruhl, an environmental law expert at Vanderbilt University.
In line with that thinking, the Biden administration announced on Thursday that it was removing a Trump-era definition of the word “habitat” from the ESA framework. This narrow interpretation made it more difficult to protect places not currently occupied by a species that climate change might make suitable or that might be restored to provide habitat. “The growing extinction crisis highlights the importance of the Endangered Species Act and efforts to conserve species before declines become irreversible,” said Shannon Estenoz, deputy secretary of the Department of Nature. ‘Indoor for Fish, Wildlife and Parks, in a press release. “Today’s action will bring the implementation of the law back into line with its original purpose and intent.”
Several endangered birds have already benefited from the current policy for experimental populations, including whooping cranes, Guam rails and California condors. Lead poisoning and other dangers reduced the condor to a small, captive population In the 1980s. But this group of breeders became the source of two experimental populations in the western United States, including a new one in May managed by the Yurok tribe in northern California. Thanks to these experimental populations, more than 300 adult California condors are free-flying.
The revised policy could help other avian species achieve similar success outside of their historic range. “I think it allows us to move things forward when it comes to our conservation actions,” says Brooke Bateman, director of climate science for the National Audubon Society. Bateman cites finches as potential beneficiaries of change. All three North American species – the black, brown-headed and grey-crowned finches – spend the summer at high elevations around remnant snowfields, which will shrink as temperatures rise. The birds are not listed as part of the ESA, but left behind on these isolated peaks, similar to island species that have little nearby habitat to migrate to, much of their current range will disappear. Moving them to more northerly peaks in the Rocky Mountains that remain cooler may become necessary to save the species. “It will be an interesting future to see how that plays out,” Bateman says.
If the FWS finalizes and implements the proposed change, it is crucial that the government does not give up on protecting existing habitat as it considers transplanting species to new territory, several experts said. Audubon. “Be careful when abandoning historic habitat and throwing in the towel,” says retired FWS biologist John Morton. Assisted migration may be a new reality on a changing planet, he says, but it should be the last resort.