Bucktoothed rodent joins region's invasive species

It's nutria, a bucktoothed rodent so pervasive in the nation's Southeast that folks swap recipes for the voracious foreign pests, which have destroyed thousands of acres of wetlands.


		Mike Urban / P-I
	Some of the region's water-loving nutria live along the shores of Lake Washington near the University of Washington campus.

A local trapper-for-hire recently nabbed nine nutria from a property on the shores of Lake Washington. Two students at the University of Washington are working on a research project to tally their numbers in wetlands near campus. And last summer, more than a dozen were caught in Skagit County in a state-led control effort.

"This is something new," said Ed Cunningham, a Highline High School educator who runs a trapping business on the side dubbed Teacher's Pest. "This is the first call I've had for this."

The semi-aquatic, chocolate-colored rodents have snuck up on local wildlife managers and residents, likely mistaken for beavers, muskrat or otters in the past.

Also called coypu, or swamp rats, the South American natives can eat one-quarter of their weight a day, powering down crops and plants of all varieties. They can weigh more than 20 pounds and burrow through marshes and levies. Females are able to produce more than a dozen offspring a year.

A population has established in Southwest Washington near Vancouver, where they've turned local dikes to "Swiss cheese," said Mike Davison, a wildlife biologist with the state Department of Fish and Wildlife who worked on the Skagit trapping project.

"It's a pretty ominous picture when you bring nutria into an area where they didn't exist before," Davison said. "There is no way of winning on this if nutria establish."

Help could be on the way. State leaders recently approved the creation of a statewide Invasive Species Council whose job it will be to track invaders such as nutria, coming up with plans for their elimination and figuring out how to get the money and manpower to do it.

"Having an Invasive Species Council is a big step forward," said Joan Cabreza, invasive species coordinator with the Northwest regional office of the U.S. Environmental Protection Agency.

Combating the invaders

A variety of foreign species has invaded Washington, requiring millions of dollars to kill them and repair their damage. The non-native plants and animals take hold in an ecosystem, preying on native species and competing with them for food and places to live and bear young. Often lacking natural enemies, they spread unchecked, destroying vegetation and wild places, trashing crops and choking waterways.

In Seattle, non-profit groups and the city are working on a 20-year plan that could cost more than $48 million to loosen the stranglehold of ivy, Himalayan blackberry vines, holly and other weeds on wooded parks and public open spaces. The foreign plants are smothering native firs and ferns. If left unchecked they could turn the land into deserts of ivy.

An attack was recently launched on a foreign species of marine life called sea squirts or "tunicates" -- squishy, globby organisms that are plaguing marinas in Hood Canal's Pleasant Harbor, Neah Bay, Blaine and likely elsewhere.

Sea squirts come in all different shapes and sizes. This variety is from Asia, looks sort of like a brown anemone and grows on stalks up to 5 inches long.

They could have "a serious impact on the shellfish industry," said Scott Smith, aquatic invasive species coordinator for the state. "It just grows over the mussels and all and completely covers them over in such dense mats it makes it hard for the shellfish to get food."

The Invasive Species Council will include six state agencies and two counties and will work with federal and other government agencies, business, tribal and non-profit groups. The council, which will meet for the first time in the next couple of months, has a $200,000 budget for this year.

There are other government groups that combat invaders -- namely noxious weed boards and an aquatic nuisance committee. The council would help address species that don't fall into those categories, raising the prominence of the issue overall and working to improve funding for addressing invaders and preventing their entry in the first place.

Some of those working on invasive species issues said it's about time that Washington caught up with other states in the region; Oregon and Idaho, for example, already have councils. Without one, important decisions and actions have languished, Cabreza said, because no single agency had the authority to act.

With invasives, a quick response is crucial.

"If you can get on these things early and get people to understand how important it is, the impact is really small," said Bill Brookreson, deputy director for the state Agriculture Department.

Experts hope that will be the case for the local nutria population.

The hunt for nutria

Toting large packs with camera gear, notebooks, water bottles and a nutria skull recovered from a road kill, Phu Van and Filip Tkaczyk are searching for the South American interlopers on the shores of Lake Washington.

The two UW undergraduates are trying to document what the rodents are eating, their numbers and where they hang out. They've set up a Web site where residents can report nutria sightings. Their work is focused on the Union Bay Natural Area, an area of fields and wetlands north of Husky Stadium.

They'd like to be able to predict where the creatures might take up residence next.

Along the shoreline, the large rodents have flattened out the grass and cattails, creating "runways" as they travel from the water to dens to fields where they graze among the Canada geese.

Then they spot one. The nutria is floating along offshore, gnawing on what appears to be the root ball from a water lily.

It's easy to identify, making three lumps in the water -- it's head, humped back and ratlike tail arched slightly out of the water.

"It's pretty distinct," Tkaczyk said. "That's a big one too."

In the 1930s and '40s, the rodents were raised in Washington and elsewhere for their fur pelts. While some animals escaped or were released, it's believed that they died out of the Puget Sound region over the years. Native to warmer climes, nutria are vulnerable to cold snaps and flooding.

Nationally, they're found in at least 15 states, including Louisiana, Texas, the Carolinas, Florida, Maryland and Oregon.

Davison, of Fish and Wildlife, suspects that they might have migrated from Southwest Washington, through the Seattle area and up into the Skagit.

He's hopeful they caught the majority of the Skagit population. With its agricultural and forestry industries and reliance on levies, the area is particularly vulnerable to economic and environmental damage caused by the pests. Traps are still being laid. Those that are caught are killed.

Cunningham, who generally deals with wayward raccoons and pesky squirrels, had never confronted a nutria when he got the call this winter from the Lake Washington homeowner. He boned up on the animals via Internet searches and reference books.

The lakeside resident was concerned about the animals defecating in his children's play areas and spreading disease.

So Cunningham deployed his traps -- a wire cage with a door that swings shut when the animals take the bait.

"Carrots work just fine, but any vegetable would work," he said. "It depends on what's on special in the grocery store when I go."

He snared nine of the rodents over a couple of weeks in February and March.

Milder weather potentially linked to global warming could have helped the nutria spread into the Puget Sound area.

A lack of predators -- caiman and alligators in their native environment -- allowed them to take hold.

"What we need to do is get some sterile alligators that like cold water," joked Cunningham. "I'm not going to get them all."

More headlines and info from Montlake, University District.

P-I reporter Lisa Stiffler can be reached at 206-448-8042 or lisastiffler@seattlepi.com. See the P-I's environmental blog at www.datelineearth.com

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