To Rid California Of Rodents Of Unusual Size, State To Use Detection Dogs And ‘Judas Nutria’

California has a rodent problem. And it's a big one.

Nutria are two-and-a-half foot long, 20-pound rodents that are often confused with beavers. The invasive species likes to burrow in the state's wetlands and vulnerable levees.

For the past year the state’s worked to eradicate the rodents for a second time. The rodents were brought to California in the 1900s for the fur trade and fur farming. The state thought it wiped out the species in the 1970s. But somehow, they came back.

“[The] challenge is we keep looking and we keep finding more nutria,” said Peter Tira with the California Department of Fish and Wildlife. “However, we do know there's about 1.8 million acres of suitable nutria habitat. This is the largest nutria eradication ever attempted in the United States."

They're caught by using cameras and traps. Tira says the state is also going to start using detection dogs and sterilized nutria equipped with special radio collars.

“We call it a Judas nutria," Tira said. "It leads biologists to other populations that we might not know about."

The state’s captured 410 within five counties — 330 from Merced, 65 from San Joaquin, 12 from Stanislaus, two from Mariposa and one from Fresno.

“There's just not the checks on their population here,” said Tira. “They reproduce exponentially. Nutria live in wetlands environments and over time they destroy those wetlands converting them into open water."

Tira says there was no special fund to help get rid of the nutria, but the department shifted its employees around to get a handle on the problem. Now more than $3 million in grants will be spent over the next three years to help get rid of them.

The big goal is to keep nutria out of the Sacramento-San Joaquin River Delta, which is the center of the state water and flood controls. Tira says there’s one population in the delta.

“They are especially problematic, because they typically burrow from underwater,” Tira said. “So, you don’t often see the damage until a levee collapses and there are numerous documented failures in places like Texas where nutria are out of control.”

Tira says there could be as many as 250,000 nutria in the state within five years — female nutria can have up to 13 young in a litter. To combat nutria population growth the agency would like funding for 10 full-time positions. In January, CDFW officials asked the state legislature for $1.9 million to pay for the positions and a wider effort to rid the state of nutria.

The state’s efforts are modeled after those in the Chesapeake Bay in the 2000s where more than 14,000 nutria were removed from 250,000 acres in the Delmarva Peninsula. Nutria are in more than a dozen U.S. states, but the Chesapeake Bay effort is the only successful, large-scale nutria eradication in U.S. history.