California's record-setting winter is providing a much-needed boost for wildlife, including blooming wildflowers and the fish and ducks that depend on thriving rivers and streams.

Still, for other animals, the rising waters are perilous. Just ask the bunnies.

In the Central Valley, evacuations are underway for endangered riparian brush rabbits. The small brown cottontails, only about a foot-long, are finding themselves stranded on small areas of dry land as nearby rivers overtop their banks.

The San Joaquin River has spread far beyond its banks as the snowpack melts in California's Sierra Nevada.

The San Joaquin River has spread far beyond its banks as the snowpack melts in California's Sierra Nevada. / NPR

A team from the U.S. Fish and Wildlife Service has captured and moved more than 360 rabbits to higher ground in an effort to protect a species that's coming back from the brink of extinction. Given the low numbers, a flood can be devastating for the population.

Very little riverside habitat is left in California's Central Valley, so the rabbits lack higher ground to move to when waters rise. Wildlife officials say with climate change bringing bigger weather disasters, it's an example of how the country's wildlife refuges may need to expand to help animals handle bigger extremes.

U.S. Fish and Wildlife Service refuge manager Eric Hopson (left) and team transport riparian brush rabbits to new habitat.

U.S. Fish and Wildlife Service refuge manager Eric Hopson (left) and team transport riparian brush rabbits to new habitat. / San Luis National Wildlife Refuge Complex

Rabbit search and rescue

To find the rabbits, the Fish and Wildlife team heads out into the San Joaquin River National Wildlife Refuge in aluminum boats. The wide, sprawling river is rushing with meltwater from the Sierra Nevada snowpack, spreading far into the surrounding groves of cottonwood trees. It's a rare scene — this river often runs completely dry some years, because it's so heavily used by farmers and cities.

The riverside habitat is the only place in the world where riparian brush rabbits are found. Today, less than 1% of the habitat remains, after much of the land was converted into agricultural fields. The San Joaquin River National Wildlife Refuge is among the few pockets left.

Refuge manager Eric Hopson pulls the team's boat onto a sandy bank covered in shrubs.

"So we have this strip of high ground that isn't flooded, but some of this is going to be flooded when the water comes up another 2 or 3 more feet," he says. Most of California's record-breaking snowpack has yet to melt, meaning the flood risk could stretch for months.

Ahead, he spots a wire cage hidden in the brush — a baited trap his team set for the rabbits. He checks and finds a rabbit waiting inside.

"In the late 1990s, they were thought to be near extinct," Hopson says. "In fact, there was a period of time when they were actually thought to be extinct."

After small groups of rabbits were discovered, a captive breeding program began to reintroduce them here. But major floods, like the ones this year, can take a toll on the highly endangered population.

Hopson's team has rescued dozens of rabbits clinging to the branches of trees and shrubs, the only place they could climb to after the floodwaters rose. This rabbit will be loaded into a cat carrier and relocated to higher ground. It will also be vaccinated against rabbit hemorrhagic disease, a deadly virus that has recently spread here.

Making wildlife refuges climate-ready

These rabbits didn't always need rescuing. Historically, flooding was the natural cycle of Central Valley rivers, which seasonally swelled when the snowpack would melt. When that happened, the rabbits would simply move to higher ground. But now, the farm fields surrounding the rabbits provide no cover from predators. With no place to move to, the rabbits are trapped.

Hopson says the refuge is looking at acquiring more land to provide higher ground for species, but it can be challenging in a prime agricultural area.

"Very few farmers are willing to sell that land, and when they are, it's very highly priced," he says.

Still, as the climate changes, California will likely see bigger weather extremes, with wet winters and hotter temperatures creating a greater risk of flooding. National refuges may need to grow and shift to provide habitat that will help wildlife adapt and be more resilient to rapidly changing conditions.

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Tags: U.S. Fish and Wildlife Service  rabbits  wildlife  California flooding  climate change