Record heat waves have scorched the Pacific Northwest in recent weeks, prompting raging fires and devastating droughts across the region. The extreme weather has been blamed for the deaths of hundreds of people. But the toll among the region’s animals has been far greater, with the shifting climate threatening to permanently alter the area’s biodiversity.
Conservationists and scientists say the changes have been coming for years: Rising temperatures have coincided with drier conditions in parts of the Pacific Northwest, shaping the ways habitats interact with organisms. The full scope of the ramifications is still being studied, but it is expected to be extensive.
“It’s a big unknown,” said Jay Kehne, a conservationist and member of Conservation Northwest, an organization that aims to protect and conserve the region’s wildland and wildlife. “It’s really hard to grasp all the changes that can come from those really incremental changes.”
How does extreme heat affect animals?
Extreme heat, coupled with drier conditions, can significantly alter animals’ habitats. Dry winters can weaken plants and their leaves, diminishing potential food sources for wildlife. Mussels, barnacles and seaweed populations have faltered, impacting shoreside food chains. The shrubsteppe, a parched ecosystem located in eastern Washington, is an essential habitat for much of the state’s fauna. However, under the strain of development and climate change, an estimated 80 percent of the shrubsteppe has been lost, according to the Washington Department of Fish and Wildlife.
Climate change “is going to affect how different plants live and or survive from seedlings on up into their adulthood,” Kehne said. “That’s going to change some of the species that occur across the landscape.”
How are animals responding to extreme heat?
Animals have different tools to protect themselves from the effects of extreme heat. Some stay in the shade, while others lurk in creeks or lakes, according to Patrick Taylor, chief of interpretation and education at Death Valley National Park.
Adult birds tend to look for shady spots across a habitat, staying in the shadows until temperatures drop. Some birds also utilize a tactic called gular fluttering, vibrating their neck muscles while their mouths are open to regulate their internal temperatures, according to Nat Seavy, the director of migration science for National Audubon Society’s Migratory Bird Initiative.
However, there is only so much an animal can do. Wildfires have scorched large sections of the Pacific Northwest’s plains and forests, depriving wildlife of an essential barrier to extreme heat — and opening the door to mass casualty events.
The same outcome has been seen elsewhere in recent years.
“One of the places where this has really been studied has been in Australia, where there have been mass mortality events during heat waves,” Seavy said. “Birds have packed into very small areas of shade, and you find hundreds if not thousands of birds that have expired from the heat.”
Which species are most at risk?
The effects of climate change on wildlife have been especially noticeable among certain species, Kehne said. Fauna that once dominated the land — such as lynxes, pygmy rabbits, sage grouse — have dramatically declined. Lynxes and pygmy rabbits are already considered endangered species in Washington state, while the greater sage-grouse population has decreased 80 percent since 1965.
The seas are also under threat, according to Chris Harley, a University of British Columbia professor and marine biologist. Vast beds of shellfish were baked alive in British Columbia earlier this month, the consequence a fatal mix of extreme heat and low tides.
Stationary organisms like mussels, barnacles and seaweed are at the most risk, Harley said.
However, extreme heat poses a threat even to animals that are more mobile because they may rely on organisms decimated by the extreme conditions.
“The mussels feed a lot of starfish. There’s migratory birds that rely on them,” Harley said. “All those species — mussels, barnacles, seaweeds — provide a lot of habitat for other things.”
How are experts responding?
As the effects of climate change become more and more evident, some experts are reevaluating their prior projections. One of Harley’s graduate students brought propane camp heaters down to the shore in the hopes of simulating a heat wave earlier in the month.
The actual heat wave that hit British Columbia was far hotter than the experiment.
“We’ve had to recalibrate our expectations and now we’re focused on what might happen in the very near future,” Harley said.
For Kehne, that means a closer examination of the effects of gradual climate change on habitats. More extreme climate events, like wildfires and lightning storms, tend to grab the headlines, Kehne said. But it’s the slight changes, those unseen by the naked eye, that threaten to disrupt the livelihoods of all sorts of wildlife across the Pacific Northwest.
“This is going to be a continual rise,” he said. “That’s really hard to get your head around and harder and harder for people to understand that it’s actually happening and try to take action to correct that.”
Experts have long looked toward extreme environments for guidance, hoping to draw meaningful lessons from habitats already facing extreme conditions, including the Mojave Desert in California and parts of Australia, Seavy said. With this information, experts hope to better predict the impacts of climate changes in other parts of the world.
What can we do?
The situation looks bleak, especially as wildfires continue to rip through the valleys and hills that cover much of the Pacific Northwest. However, there are actions people can take in the interim to help provide temporary reprieve for some species.
Extreme heat places nesting birds at significant risk, Seavy said, a consequence of their less mobile nature. Still, nesting boxes and bird-friendly garden landscapes can provide birds with safe alternatives to their natural habitats — which is especially crucial when those environments are under threat, Seavy said. Audubon has a database of native plants that attract and protect birds on its website.
Shocks in seafood production also threaten to harm shellfish growers and Indigenous communities in the United States and Canada. As those communities assess the long-term impact of climate change on their local shoreside environments, it may open up new possibilities for sustainability and conservation.
The implications of climate change are far-reaching and will only continue to threaten at-risk populations, Kehne said. Climate-related migration will likely increase, as will mass mortality events. Just last year, half of Washington’s pygmy rabbit population was killed during wildfires. Now, only about 90 remain, Kehne said.
Still, experts remain hopeful that the worst impacts can be averted. Climate change is becoming more evident to both researchers and the general public. As the problems become clearer, perhaps so will the solutions, Harley said.
“I think it is important not to lose hope,” Harley said. “It’s really bad. But if we can understand it, that helps us plan. And hopefully, we can all make small steps to make these things less likely in the future.”