Researcher climbing up to the eagles’ nest. A pair of eaglets are nesting there. (Photo by Bob Kelleher)
The American Bald Eagle is expected to come off the endangered species list soon. Once a victim of hunting and pollution, the eagles are rebounding, but scientists say monitoring must continue, for the sake of the eagles and the sake of the environment. The Great Lakes Radio Consortium’s Bob Kelleher reports:
Transcript
The American Bald Eagle is expected to come off the endangered species
list soon. Once a victim of hunting and pollution, the eagles are
rebounding, but scientists say monitoring must continue, for the sake
of the eagles and the sake of the environment. The Great Lakes Radio
Consortium’s Bob Kelleher reports:
If you’re looking at all, it’s hard to miss the bald eagles here. The
majestic birds glide overhead, or silently perch on a waterfront tree.
Their nests – made of branches – fill the treetops – sometimes ten feet
across, close to the lakes of Northern Minnesota’s Voyageurs National
Park.
Twenty years ago you might have been hard pressed to spot America’s
national symbol. Park Biologist Lee Grim says, it was obvious that
eagles were struggling.
“We saw how some of these birds were ill, and sick, and they had avian
pox and things. Something was keeping them from being healthy.”
An eagle found here in 1989 had the highest blood concentration ever
found of contaminants like the chemical PCB.
“So, we wanted to know why is that up here in Northern Minnesota, in
the middle of a beautiful, you know, almost wilderness area.”
It’s still a mystery how industrial chemicals like PCB’s get here, but
we do know what’s hurt the bald eagles in the past. The insecticide
DDT made bird eggs fragile – more likely to break under an eagles
weight than hatch. And Grim says DDT was all over the place. It was
sprayed on the region’s forests to kill insects like the spruce
budworm.
“DDT is pretty much everywhere, it has been, you know. And it’s a
pretty long lived chemical.”
At the top of the food chain, chemicals like DDT accumulate in the
eagle’s bodies. Sick eagles can indicate a poisoned environment. To
test the environment, you test the eagles.
(snd of climbing)
A naturalist is scaling 90-feet up one of the park’s White Pine trees
to the huge nest at the top. The parent eagles circle overhead –
noisily upset. There’s a pair of hatchlings – fuzzy, beaky, and
surprisingly big 8-week old bald eagles. They have bright yellow feet,
with shiny black, and what will become very dangerous talons. Soon,
one’s squirming in an orange bag, and lowered into the hands of
graduate students Faith Wiley and Katie Parmentier.
(snd of students talking about baby eagle)
In minutes, the young female is back up; short a few feathers for
mercury testing; and a little blood for other chemical tests. There’s
a pair of metal bands riveted around her ankles.
Bill Bowerman is an environmental toxicologist from Clemson University.
His testing proves that chemicals like DDT and PCB’s are slowly going
away, but chemicals were only part of the problems for bald eagles.
Man was another problem. It took decades to get people to stop
shooting eagles; or to catch them accidentally in beaver traps, but
it’s better now.
“It’s evident, when I go out to landowners that have eagle nests on
their property, that they know how to manage their eagles; how to keep
people away; and how to protect that eagle during that critical nesting
period.”
It’s believed there were once half a million bald eagles in North
America. As people spread, by the 1950’s, bald eagles nearly vanished.
In the lower 48 states, the last few hung on in places like the Great
Lakes.
In Voyageurs Park, bald eagle numbers have jumped from seven nesting
pairs in 1973, to 28 pairs today. There are more than 7-thousand
breeding pairs nation wide, but there are always new threats. One of
the nation’s first victim’s to West Nile disease was the bald eagle in
New York area zoos. Bowerman says several pair are missing now in
Michigan, and there are always new chemicals. Traces of poly
brominated flame retardants are doubling in the Great Lakes basin every
3 to 5 years. Bowerman says the chemical industry needs strict
monitoring.
“As long as we maintain our vigilance about the environmental toxicants
that are being created each year, we should be having the eagles
protected.”
Bowerman supports de-listing, but doesn’t want the birds in the
predicament they were twenty years ago. An official announcement of
the bald eagle’s de-listing is expected later this year.
For the Great Lakes Radio Consortium, I’m Bob Kelleher.