Researchers with state and federal agencies say Wyoming's population of loons, aquatic nesting birds found in many parts of North America, is down to just 14 pairs of the animals.

The population in the northwest corner of the state is one of just a few remaining in the western United States, say researchers attempting to find out why their numbers are dwindling and if that decline can be reversed.

The Biodiversity Research Institute, a nonprofit working out of Maine, is in the second year of a 5-year study in collaboration with Wyoming's Game and Fish Department and a number of federal agencies.

"We're trying to stabilize the population and identify threats," institute Executive Director David Evers said. "Loons are very poor colonizers. If you lose your population, even though it's good habitat, it could be a long, long time before you see more loons breeding here."

A number of factors are behind the decline in loon numbers, experts said, including destruction of habitat, climate change and acid rain.

Loons are also threatened by lead shot in the environment from hunting; an adult loon that ingests lead shot can die within weeks, they said.

They are also prone to human disturbance, Evers said, stressing the importance of educating people about loons.

Contrary to what some people believe, loons and humans can share a water habitat, he said.

"If people give loons space, people can live on the lakes and boat on the lakes," Evers said. "Some of the threats we know from human disturbance are people coming into loon territory and just not knowing how to behave or not knowing loons are there."

Loons, whose main food source is fish, need lakes with a surface area of a minimum of 20 acres for their nests, building them on shorelines or on small islands within a lake.

Loon pairs generally produce just a single chick every other year, making it difficult to keep populations up in the face of threats, experts said. They are strong swimmers, but because of placement of their webbed feet they don't walk on land, but instead scoot, so their nests are close to the water.

Some state and federal wildlife agencies have proposed building artificial floating islands for loons to use as nesting sites.

There are also proposals to move loon chicks to new locations or into other struggling populations -- similar efforts have been successful in helping bolster swan populations -- but such translocations have never been attempted with loons, said Wyoming Game and Fish Department biologist Susan Patla.

The state of loon populations can be an indicator of problems in the ecosystem of water environments, she said.

"If something was going on with the species, it could point a finger or help us understand what was going on with the wetland environment."