Saving wildlife in a warmer world
A warmer world will have adverse effects on wildlife. We can help save animals, but it will take savvier approaches, scientists say.
Whether itâs a polar bear clinging to a melting iceberg in the Arctic or a tiny, rabbitlike pika panting atop a warming mountain in western North America, scientists say that these species and others could be historical footnotes unless people help them survive.
Pushing animals to the brink â and then trying to bring them back â is nothing new for humans. Remedies have long included setting aside land for a special habitat (spotted owls) or making it illegal to kill them (whooping cranes).
But sweeping changes that would accompany projected climate change mean that an animalâs traditional range may no longer be habitable to it in a few years â or that a key food source or resource it needs is disappearing. And that calls for different solutions from those in the past.
âThe business-as-usual approach to managing wildlife populations and resources is no longer likely to work very well,â says John Wiens, chief conservation science officer for the Point Reyes Bird Observatory in Petaluma, Calif. âWe canât say anymore, âHey, weâll do some management to control this threat, and everything will be hunky-dory,â or âPreserve some habitat and some organisms, and everything will be fine.â â
There are signs of positive action, however. After years of what many saw as foot-dragging, the US Fish and Wildlife Service (FWS) is leading states and other organizations in taking the first steps toward what could become a radical departure from todayâs species-recovery model.
The FWSâs plan is a comprehensive and predictive âadaptation managementâ plan to help troubled wildlife. Its centerpiece is the creation of eight new regional landscape conservation cooperatives (LCCs), the first of up to 20 nationwide that will enlist multiple partners to deal with global warmingâs expected effects.
Along with the US Geological Survey (USGS), states, and others, the FWS is now holding regional conferences on how to shape the cooperatives.
âWeâre just at the very beginning stages of LCC development,â says Dan Ashe, deputy director of the FWS, in a phone interview. âWe have to be able to be more predictive, to be able to look into the future to how climate change is affecting species like the grizzly bear, polar bear, or coho salmon.â
Gazing into the future is the key. Last month, Congress provided $25 million in fresh funding for the cooperatives, each of which will have a core staff of scientists to create models of probable regional climate impacts and provide scientific analysis for future wildlife management plans.
âThe LCCs are integral to climate adaptation efforts,â according to an internal agency draft âfunction and formâ document. Even so, they will not be âclimate-centric,â but will âprovide scientific support for conservation actions addressing a variety of broad-scale challenges, including water scarcity, species invasion, wildlife disease, as well as changing climate.
Using advanced computer models, LCC scientists will report how global warming could change regional ecosystems decades from now, allowing researchers to calculate whether a recovery plan in a speciesâ home range makes sense.
That, in turn, might make it possible to determine if a wildlife corridor, a way for animals to migrate past highways and cities to cooler northern climes, is possible. Or whether more drastic measures â such as translocating a species (capturing and moving it) â are necessary.
Scott Loarieâs pioneering work points to a decline of up to 59 percent in pika populations across the western US if greenhouse-gas emissions reach the higher end of the scale predicted by the International Panel on Climate Change. Even under the most optimistic IPCC scenarios, 15 percent of pikas would disappear. Higher levels of decline could bring calls for more radical adaptive techniques.
Options for the pika, which requires temperatures below 80 degrees F., could include spending more time underground to avoid the heat. But that may mean pikas couldnât graze sufficiently to get fat enough to survive the winter. says Dr. Loarie, a researcher with the Carnegie Institution for Science at Stanford University in California.
However, âif policymakers create larger areas that lessen sheep grazing and logging at higher altitudes, that management might help their chances a lot,â Loarie says.
More radical measures, such as translocating pikas, are hotly debated. âTranslocation of the pika brings up all kinds of ethical questions, mainly the issue of native versus invasive species,â he says.
âIf you take a climate refugee and bring it to another range, does it become an exotic species? It opens a huge can of worms,â he says. âDo we know enough to engineer things to get the outcome we want or [do we] risk making things worse?â
Whatâs become clear is that saving wildlife species threatened by climate change requires global cooperation, which presents challenges to scientists and negotiators.
Last month, for example, the FWS identified more than 200,000 square miles as critical habitat for the endangered polar bear. âWeâve listed the polar bear under the Endangered Species Act here in the US, but we canât begin to conserve them just within our own borders,â Mr. Ashe says. âWe are having to reach out to nine countries that manage them to put together an adaptation strategy.â
Climate impacts can appear suddenly, even for species that had been recovering well. The grizzly bears of Yellowstone National Park are an example. Their numbers had been rebounding, but now climate change-linked beetle infestations and disease have killed 60 percent of the white bark pine in Yellowstone â and much of whatâs left is expected to be dead in five to seven years.
White bark pine nuts are a critical food that helps grizzlies get fat enough to overwinter. With the white bark pine gone, some 300 to 400 grizzlies need to spread out to other areas to find food. Bears are already turning to elk as a food source and getting shot by frightened elk hunters as a result.
âWhen they hear a gunshot. thereâs a bit of a dinner-bell effect,â says Louisa Willcox, senior wildlife advocate with the Natural Resources Defense Council in Montana. âThe result is more surprise encounters [between humans and grizzlies], with bears and hunters ending up at the elk carcass at the same time.â
Grizzlies will need more âconnected habitatâ â corridors or even islands of land where they can safely move between mountain range habitats as they forage more widely for food, she says.
âConnectivityâ is a buzzword among biologists like Dr. Wiens. Enabling wildlife to migrate to survive the heat is about more than just north-south corridors. Itâs recognizing âenvironmental gradientsâ â mapping climate impacts across now-protected areas and other types of land use, and âhow land use and protection can be designed to enhance movement along the gradients,â he says.
Unpublished data released by the USGS indicates that by 2100, climate change will drastically alter the biological environment (biomes) of many of the 520 national wildlife refuges in the US. At least 65 percent of the refuges would be sharply different biomes than today, with 9 percent straddling their current zone and 26 percent remaining the same.
Such warming is widespread, with more pronounced effects in the Arctic, where sea ice hit record low levels in 2007, 30 years sooner than climate models had once predicted.
On the densely populated East Coast, where animals that need a cooler climate might be blocked by urban areas as they try to move northward, the Appalachian Trail could be used by biologists as a major north-south corridor to channel key species northward, says Douglas Inkley, senior scientist with the National Wildlife Federation.
âAs a profession, [wildlife biologists] are in the very nascent stage of figuring out how to do adaptive management,â he says. âTo do vulnerability assessments, we must downscale climate models to local levels, then model biological and ecological impacts. We donât have the climate data localized yet, which is the reason itâs such a challenge. Itâs an urgent issue.â
Editorâs note: See alsothe sidebar, Ways to help wildlife adapt to a warmer world.
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