May 6, 2015
The Washington Post
For the giant kangaroo rat, death by nature is normally swift and dramatic: a hopeless dash for safety followed by a blood-curdling squeak as their bellies are torn open by eagles, foxes, bobcats and owls.
They’re not supposed to die the way they are today — emaciated and starved, their once abundant population dwindling to near nothing on California’s sprawling Carrizo Plain, about 100 miles northwest of Los Angeles, where the drought is turning hundreds of thousands of acres of grassland into desert.
Without grass, long-legged kangaroo rats cannot eat. And as they go, so go a variety of threatened animals that depend on the keystone species to live. “That whole ecosystem changes without the giant kangaroo rat,” said Justin Brashares, an associate professor of wildlife ecology and conservation at the University of California at Berkeley.
Endangered kangaroo rats are just one falling tile in the drought’s domino effect on wildlife in the lower Western states. Large fish kills are happening in several states as waters heated by higher temperatures drain and lose oxygen. In Northern California, salmon eggs have virtually disappeared as water levels fall. Thousands of migrating birds are crowding into wetlands shrunk by drought, risking the spread of disease that can cause huge die-offs.
As the baking Western landscape becomes hotter and drier, land animals are being forced to seek water and food far outside their normal range. Herbivores such as deer and rabbits searching for a meal in urban gardens in Reno are sometimes pursued by hawks, bobcats and mountain lions. In Arizona, rattlesnakes have come to Flagstaff, joining bears and other animals in search of food that no longer exists in their habitat.
“You think about it. In our urban environments, we have artificial water. We’re not relying on creeks,” said David Catalano, a supervisory biologist for the Nevada Department of Wildlife. “We have sprinkling systems. We water bushes with fruit and water gardens. That’s just a magnet for everything.
“We’ve seen an increase in coyote calls, bear calls, mountain lion calls — all the way to mice and deer,” Catalano said of the distress calls made to his department by residents. “At your house, everything is green and growing and flowering, and they’re being drawn to it.”
The state wildlife agency said it is preparing for a deluge of calls reporting bear sightings from Lake Tahoe this summer when berries and other foods they eat disappear for lack of rain.
About 4,000 mule deer have vanished from a mountain range near Reno since late last year, probably because of drought. “Our level of concern is very high,” Catalano said. Nevada has placed low fiberglass pools called guzzlers that hold up to 3,600 gallons of water at more than 1,000 wilderness areas across the state to provide water for wildlife.
For a second year, the Arizona Game and Fish Department warned people in Flagstaff, near Grand Canyon National Park: “Don’t be surprised if you see more wild animals around town in the next few months. Drought conditions may cause creatures like elk, deer, bobcats, foxes, coyotes and even bears to wander further into town than normal, as they seek sources of food and water.”
Don’t feed them, the department cautioned. Remove pet food, water bowls, garbage and other items that attract wild animals. It does more harm than good.
In California, where mandatory water restrictions were passed by the state water board on Tuesday, humans are already coming into contact with desperate wildlife from the 250,000-acre Carrizo Plain National Monument in the Central Valley, near Bakersfield.
“Just today, 20 minutes ago, four coyote cubs arrived” from Bakersfield’s outskirts, said Don Richardson, curator of animals for the California Living Museum, which has an animal shelter in the city.
“We actually get everything from reptiles to mammals,” Richardson said. “We have 13 San Joaquin kit foxes, an endangered species. They were abandoned, orphaned. The kit foxes’ health was impacted by the struggle to make it with reduced resources. Then, of course, we see a lot of birds of prey — owls and golden eagles.”
The animals are already suffering from the fragmentation of their habitat because of ranching and urban development. “It’s looking to be a very, very difficult year for wildlife,” Richardson said.
Endangered San Joaquin kit foxes, coyotes and birds in the wildlands outside Bakersfield all rely on the giant kangaroo rat to survive. But those rodents are struggling themselves.
“We fear that a semi-arid grassland is becoming a desert,” said Brashares. “The giant kangaroo rat can’t survive in desert.”
A study by the university recorded a 95 percent population loss since 2010.
Before the drought, 60 percent of their habitat was covered in grasses that they eat and seeds that they store for hard times in a network of underground burrows, Brashares said. Four years of little rain has reduced the cover to 18 percent.
“They simply lack food, so they starve,” Brashares said. As the state wildfire season approaches, the remaining grasses could be wiped out.
For a study, biologists caught a few kangaroo rats this year to study their condition. “They were skinny,” Brashares said. “We looked at females to see whether they had young, whether they were lactating.” They weren’t.
In this reality, where food is scarce and births are few, kangaroo rats are still a top prey, further shrinking their numbers.
The demise of this species would be unthinkable, Brashares said. There’s no overstating how important the rodent is in the ecosystem. Few others are around to feed snakes, badgers, weasels and animals already mentioned. Even the soil kangaroo rats dig for burrows creates moist habitat for insects.
A worse situation is hard to imagine, said Stafford Lehr, chief of fisheries for the California Department of Fish and Wildlife. But there is one.
Chinook salmon are in great danger, he said. For two years, only 5 percent of their eggs have survived winter and spring migrations because the cold water their eggs need to survive drains from rivers and reservoirs.
“If you draw down a reservoir, cold water at the bottom drains first,” Lehr said.
To save them, wildlife officials tried to replenish cold water that drained from Shasta Lake north of Sacramento last year. “It didn’t work,” Lehr said.
“Ninety-five percent of eggs and juvenile brood in 2014 were killed,” Lehr said. “Those would be expected to return three years later. We also had heavy mortality in 2013, expected back in 2016. The 2015 fish are spawning right now. We’re trying everything in our power to have enough cold water in Shasta so we don’t have what we had last year.”
Salmon are only part of the problem. Smelt are at the lowest number ever recorded in the state. They are a major forage fish, feeding other fish and birds in the marine ecosystem.
“It’s part of the heritage resource in the state of California. It’s our responsibility to ensure they are protected,” Lehr said. “Every time you lose something, it puts pressure on the environment.
“You lose it and something else will replace it, but it will be lost. They’re part of the ecosystem. Millions of dollars have been invested in their survival.”