River otters are recolonizing in eastern North Dakota, but don't expect to see the torpedo-shaped, brown mammals in the Missouri River anytime soon.

The Red River of the North and its tributaries are the focus of an ongoing research project to evaluate the distribution of river otters and other mid-sized carnivores.

The man overseeing the project is Tom Serfass, a professor of wildlife ecology at Frostburg State University in Frostburg, Md. He was in Bismarck Thursday to meet with state and federal wildlife researchers.

Graduate students have been doing field work on the project for more than a year, traveling "up and down the Red and tributaries of the Red in boats, canoes and walking to detect droppings," said Serfass, who holds a Ph.D. in wildlife and fisheries science from Pennsylvania State University. The project will last two years, and not only will determine where otters are coming from, but how they are doing.

He already had put in time along the Red River with the students despite the high water.

"Walking around the last week with four inches of mud on your boots makes you feel tall," he joked.

River otters are identified as a species of conservation priority by the North Dakota Game and Fish Department.

The project will help researchers in the future keep up with the state's otter population, said Patrick Isakson, a NDGFD nongame biologist.

"We will know where when we go out in three, five or 10 years," he said. "It's important to do what we have in our power to keep them here."

Federal funding helps researchers keep up with otters and other critters that don't get the same attention as game animals, such as white-tailed deer.

"It's what State Wildlife Grants were developed for," said Isakson.

River otters once were found on all major water systems in the state and on most major waters across the country, Serfass said.

"They disappeared across a large portion of the United States in the late 1800s before there were wildlife agencies, seasons and bag limits. They were vulnerable to overharvest," said Serfass.

While many states have implemented projects to bring river otters back, the dark brown mammals are doing it on their own in North Dakota.

"They are unique here. They are coming in naturally," said Serfass. "We think they are expanding from Minnesota."

Researchers will expand to the Turtle Mountains this year in hopes of tracking distribution of otters and also fishers and martens, said Serfass.

Five otters have been documented on the Forest River, northwest of Grand Forks.

A student new to the project spotted the otters.

"We were skeptical until we saw the tracks," said Serfass.

Otters also have been seen and photographed in the Grand Forks area.

There also is an otter population on the eastern part of the Yellowstone River in Montana.

"They have been sighted at Lake Sakakawea, but not confirmed," said Dorothy Fecske, NDGFD furbearer biologist.

Otters are considered furbearers with a closed season.

Two otters were trapped accidentally last season in North Dakota, and both were turned over to NDGFD, said Fecske, who will do necropsies to determine gender and diet, among other things.

It's conceivable river otters, which are about the size and shape of a dachshund, eventually could expand to the Missouri River, Serfass said.

"In North Dakota, there's a limited amount of aquatic habitat, which is what made them vulnerable," he said.

If otters do re-establish themselves on the Missouri, they won't compete with anglers for walleyes.

"I don't think walleyes are a major part of their diet," he said. "I think the common carp. It's slow and abundant."

(Reach outdoor writer Richard Hinton at 250-8256 or richard.hinton@;bismarcktribune.com.)