It was a race against nightfall. As he hurried across the sandy, bristling landscape of California’s Carrizo Plain, ecologist Ian Axsom stopped every 10 yards to place an aluminum live trap on the ground, eventually distributing traps over an area the size of two baseball fields. Against the rolling playas and tawny mountains, the traps glinted with golden remnants of the September dusk.
Axsom had no time to admire the view. Then again, as a land steward at the Sequoia Riverlands Trust, he’d already seen plenty of striking skies. “If you spend enough time out here, you will inevitably end up trying to take pictures of amazing sunsets on your phone, and it never quite captures it the way the colors look,” he said.
Three of his teammates trailed behind him, pausing at each trap to insert a fistful of bird seed mix and set its trigger. Finally, the traps were ready for their target: the nocturnal giant kangaroo rat, Dipodomys ingens, a keystone species of the Carrizo Plain.
The trapping was part of the trust’s ongoing effort to monitor kangaroo rats on the Carrizo Plain, located at the southwesternmost edge of the San Joaquin Valley, which stretches 250 miles from Stockton southeast to Bakersfield. The valley is a geographical palimpsest marked by urbanization, drilling and, most of all, agriculture. But the Carrizo Plain is still relatively undeveloped — a time capsule, a remnant of the ecosystem that predated European settlement.
Regular surveys of the giant kangaroo rat — named for its two-legged hopping gait — indicate how the species and its habitat are faring. In particular, they provide a baseline for measuring the effects of the plain’s development, which now includes two solar farms.
By the time Axsom’s team set up the last trap, the sun had set behind the mountains, and the group used cellphone flashlights to return to their vehicles. The day’s scorching temperatures had fallen, a prelude to the night’s chill. It was time to drive away and wait.
THE CARRIZO PLAIN is one of Central California’s best-kept secrets. The semi-arid grassland lies more than 1500 feet above the San Joaquin Valley floor, sandwiched between the Caliente Range to the southwest and the Temblor Range to the northeast. It’s best known for the weeks-long spectacular superblooms that occur when droughts are followed by unusually heavy rainfall. But most of the time, the Carrizo sees little human presence. As one frequent visitor noted in his blog, “In all the trips I’ve taken to the Carrizo, I still have seen far more pronghorn than I have other people.”
Axsom, who grew up in San Luis Obispo, less than two hours’ drive away, said he didn’t even know about the plain until he was an adult.
The Carrizo Plain’s scarce precipitation has long limited human activities. The Chumash, Yokuts and other Indigenous peoples lived on and around the plain for millennia and still have cultural ties to the landscape. In the 1800s, after European colonists had decimated California’s Indigenous population through introduced disease and forced labor, settlers on the plain began to practice dryland grain farming and livestock grazing. California’s state and federal irrigation projects, built in the 19th and 20th centuries, never made it here, so the plain largely avoided intensive agricultural development. Mid-20th-century plans to build more than 7,000 homes never took off, though the area saw a boom in marijuana cultivation and the construction of two solar farms in the 2010s. Today, the few thousand people who live in the area still rely on wells and bottled water.
“In all the trips I’ve taken to the Carrizo, I have seen far more pronghorn than I have other people.”
Since humans have largely stayed away, the plain — especially its southern portion — has become a refuge for native species. It is currently home to one of the highest concentrations of vulnerable species in the state, including more than 36 rare and endangered plants. Blunt-nosed leopard lizards and San Joaquin antelope squirrels emerge from their burrows during the day, and San Joaquin kit foxes and American badgers awaken at night. In winter, migratory birds take refuge at the ephemeral Soda Lake at the north end of Carrizo Plain National Monument, where fairy and brine shrimp provide a vital food source. Tule elk graze on the plain year-round.
The Carrizo Plain and the surrounding San Joaquin Desert “is not the prettiest place on Earth,” acknowledged Tim Bean, an ecologist at California Polytechnic State University in San Luis Obispo. “But the thing that makes it really special is the animals that live here that are found nowhere else.”
Undergirding the ecosystem are the giant kangaroo rats, whose burrows blanket the landscape. To better spot approaching predators, they industriously clip the grass around their burrows, creating bare “crop circles” that are visible from outer space. Studies have shown that this “gardening” increases plant biodiversity, keeps invasive grasses at bay, and helps other animals move more easily through the grassland.
“When you step back and look at what makes the San Joaquin Desert function, giant kangaroo rats just keep coming up over and over,” Bean said. Plus, they’re cute: “Our state mascot should be the kangaroo rat.”
THE METAL TRAP thrummed with barely contained energy. It was around midnight, and by the light of her headlamp, one of the volunteers, a wildlife biologist named Courtney Tuskan, tipped the trap’s occupant into a cloth sack. As Tuskan reached in to fish out the squirming rodent, her colleague, Sequoia Riverlands Trust biologist Lindsay Peria, reminded her to weigh the bag first so that the rat’s heft could be calculated later. “Man, I forget everything when I’m with an animal,” Tuskan replied.
The captive was a feisty young male slightly bigger than a clenched fist. Its oversized, neckless noggin gave it a hunched posture, and its tufted tail whipped about saucily. The rat’s brindle fur was silky and warm, and its cheek pouches were so stuffed with seed bait that it seemed to be grinning.
Working as quickly as she could, Tuskan measured the rat’s head size and foot length, then marked her subject on the belly with a Sharpie to avoid measuring it twice over the next few nights. Upon release, the indignant captive calmed, and its first lazy hop brought it smack into the tip of Axsom’s boot. He couldn’t resist stroking the rat with a finger before it retreated into the shadows.
Today, giant kangaroo rats occupy less than 5% of their historic range, which spanned the length of the San Joaquin Valley. After the California State Water Project accelerated agricultural expansion in the 1960s, the species’ numbers plummeted. In the 1980s, the giant kangaroo rat was listed as a state and federally endangered species. And two decades later, in 2001, the animal’s protected status helped spur the establishment of the national monument on the southern part of the plain.
[The Carrizo Plain and the surrounding San Joaquin Desert] “is not the prettiest place on Earth, but the thing that makes it really special is the animals that live here that are found nowhere else.”
Environmental groups raced to translocate some of the species’ remaining populations to its former habitats. One such recolonization effort occurred on the Carrizo Plain in 1989. Over the years that followed, environmental groups also restored habitats degraded by trash and rodenticide use, especially on abandoned marijuana farms. Landowners and land managers grazed cattle in an effort to create more habitat for imperiled species. Around 2010, after two energy companies proposed building solar farms on the monument’s doorstep, the federal government required them to fund habitat mitigation efforts and monitor their ecological impact through regular wildlife surveys.
On the Carrizo Plain, the number of giant kangaroo rats has rebounded from an estimated few thousand in the 1990s to millions today — a healthy population now protected by the national monument. “The monument is working and doing its job,” Bean said.
The Carrizo Plain is isolated in a sea of development. But that may change: The San Andreas Corridor initiative, led by The Nature Conservancy, would connect the Carrizo with other conservation lands to create a 600,000-acre passage for wildlife. A loose coalition of environmental groups, including The Nature Conservancy and Sequoia Riverlands Trust, has been acquiring parcels of private land from willing sellers and working with ranchers and other landowners to establish conservation easements, binding agreements that protect habitat by limiting development on private land.
It was past 1 a.m. when Axsom’s group finished checking the traps, and they gathered in a circle of headlamps to tally the numbers. They had caught eight, fewer than Axsom had predicted. But he wasn’t too worried. All around them were signs of giant kangaroo rat activity: black droppings, grass clippings next to burrow entrances, piles of seed heads picked clean, and the chalky poop of the San Joaquin kit foxes that prey on the species. The entire landscape was a checkerboard of hole-dotted burrow mounds among dried clumps of fiddlenecks and invasive red brome.
Coyotes caroled in the distance, and the screeches of a pallid bat shattered the peace of the night. Under the riot of stars, the group headed home, eager for sleep.
This story is part of High Country News’ Conservation Beyond Boundaries project, which is supported by the BAND Foundation.
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This article appeared in the February 2026 print edition of the magazine with the headline “Where giant kangaroo rats thrive.”
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