Higher mercury found in eagles

BILLINGS – Heightened levels of mercury have been blamed for the death of two bald eagles in Montana and detected in about 10 others, and officials aren’t sure why.

The Montana Raptor Conservation Center in Bozeman has been testing eagles for the element since a bird brought in several months ago with signs of lead poisoning tested negative for lead but positive for mercury.

Since then, the center has detected heightened levels of mercury in 10 to 12 bald eagles, and two have died.

It’s too early to tell if the high levels are simply a result of investigators looking for it or if something else is going on.

“We don’t know,” said the center’s Radell Key. “It’s just something we’ve started looking at.”

Kristi DuBois, chairwoman of the Montana Bald Eagle Working Group and native species coordinator for the Montana Department of Fish, Wildlife and Parks, said Montana’s overall bald eagle population is doing well, but those found with mercury “raise some red flags.”

“The fact that there are a few birds that died may be a warning sign for us,” DuBois said. “The key is to find where it’s coming from.”

There are nearly 400 breeding pairs of bald eagles in Montana, compared with just 12 in 1978. A 1972 ban of the pesticide DDT, which caused eagles’ eggs to thin and break, and increased protection measures are credited with increasing the population of bald eagles nationwide.