With the rapid spread of West Nile, more communities are faced with the question of whether to use pesticides to control mosquitoes, which carry the virus. One town is trying a new approach: fish. The Great Lakes Radio Consortium’s Lisa Phillips reports:
Transcript
With the rapid spread of West Nile, more communities are faced with the question of whether to
use pesticides to control mosquitoes, which carry the virus. One town is trying a new approach –
fish. The Great Lakes Radio Consortium’s Lisa Phillips reports:
Non-native “mosquito fish,” also known as gambusia, have been used for years as a weapon
against the insect in parts of Asia and the American West. One town in upstate New York,
Guilderland, is trying something a little different: stocking a town pond with native species such
as sunfish and golden shiner.
Ward Stone is New York State’s Wildlife Pathologist. He says more communities should
consider doing the same.
“West Nile’s going to be around, and by lowering the mosquito population it makes it a little bit
safer. And they’re not applying any pesticides to it. We should encourage that.”
Stone says the fish program is limited because mosquitoes often breed in pools of water too small
for fish. But complaints about mosquitoes have decreased in the neighborhood near the pond,
and the town has decided to expand the program.
For the Great Lakes Radio Consortium, I’m Lisa Phillips.
A new federal plan will grant state wildlife officers the ability to control local populations of double-crested cormorants. The Great Lakes Radio Consortium’s Karen Kelly reports:
Transcript
A new federal plan will grant state wildlife officers the ability to control local populations of
double-crested cormorants. The Great Lakes Radio Consortium’s Karen Kelly reports:
Double-crested cormorants are big fish eaters. And the birds have wreaked havoc on game fish
populations throughout the Great Lakes.
Up until now, states needed a federal permit to disturb or destroy the cormorant eggs and the
birds themselves. A new federal plan will allow agencies in 24 states to control the cormorants
on their own.
Shawna Hanisch is a biologist with U.S. Fish and Wildlife.
“It allows them to carry out control more quickly. They don’t have to go through the permit
process. And if there’s a problem, they want to prevent it before it even gets started, you know,
before it becomes a serious problem, they can go ahead and take action.”
Hanisch is quick to point out that state and tribal officials are the only people allowed to kill or
disturb the birds.
The service ruled against a cormorant hunting season.
For the Great Lakes Radio Consortium, I’m Karen Kelly.
Researchers collect as much information as they can to take advantage of the rare opportunity of being close to a
tranquilized moose. Photo by Stephanie Hemphill.
Biologists fit the moose with tags. The study will track 60 moose for five years, to learn what factors are limiting the population in Northeastern Minnesota. Photo by Stephanie Hemphill.
A bull moose walks away after being fitted with a radio collar. Photo courtesy Pam Coy, Minnesota DNR.
Many wildlife lovers consider moose to have a special mystique. Adult moose are bigger than horses, and they seem fearless. But biologists don’t know much about many moose populations. A team of researchers is just beginning to learn about one herd of 4,000 moose in the Northwoods. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:
Transcript
Many wildlife lovers consider moose to have a special mystique. Adult moose are bigger than
horses, and they seem fearless. But biologists don’t know much about many moose populations.
A team of researchers is just beginning to learn about one herd of 4,000 moose in the
northwoods. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:
Half a dozen big four-wheel-drive pickups are parked at a boat landing on MacDougal Lake. It’s
about 30 miles west of the Lake Superior shore, in the heart of the Superior National Forest in
Northeastern Minnesota. The forest is twice the size of Delaware.
It’s 25 degrees. At the edge of the frozen lake, men in conservation officer uniforms are standing
around a small fire. They’re waiting to hear from the helicopter. The crew on the helicopter is
shooting moose with a tranquilizer gun. They need to get up close to the animals to learn more
about them.
Scientists think more moose could be living in this area. Mike Shrage is a biologist with the
Fond du Lac band of Chippewa. He says they’d like to know why there aren’t more moose here.
There are several possible reasons.
“Wolves, bears, lack of habitat, hunting and other kinds of human-related mortality, automobile
accidents.”
Shrage is listening to a radio cradled in a canvas holster on his shoulder. He cocks his head to
catch every word.
“There’s three of them there.”
The helicopter crew has spotted some moose.
“Yeah, I think they’re bulls.”
“These are three bulls. It’s not uncommon this time of year, you’ll get small groups of them
hanging together for awhile. Little bachelor groups.”
Shrage says the helicopter crew will try to chase one of the moose into an open area, like a frozen
lake, where they can get an easy shot.
“And if it lays down right in the lake, then they can sit down on the ice next to it. It makes
everything a lot easier.”
“Yeah, he’s gonna hopefully drop in the spot where they can get right to him.”
“I think they must already have a dart in him and they’re just waiting for it to take effect.”
The helicopter drops off a crew member to stay with the moose, and comes back to the boat
landing to pick up a radio collar.
(sound of helicopter)
Counting moose is a challenge. A recent survey in this area showed a drop from 5,000 to 4,000
animals in one year. But researchers admit there could be a 25% margin of error in those figures.
That’s because it’s hard to find the moose in heavily wooded areas. The collaring project will
make counts more accurate.
Three biologists are gathered around the latest moose to be fitted with a collar. He’s a mature
bull. He’s lying on his side in the middle of a huge frozen swamp.
He’s blindfolded to make the process less stressful. He seems to snore, while the biologists poke
and prod.
They take blood samples to check on hormones and blood chemistry, and to look for disease.
They also pull a tooth to send to a lab. They can get an exact age by measuring the rings on the
tooth.
Glenn Delgiudice takes notes on the animal’s fat reserves. That’s a good indication of its overall
health.
Delgiudice even uses an ultrasound machine to measure the fat in the moose’s rear end.
“Rump fat is one of the main fat depots of these animals, and also one of the first to go. They
mobilize their fat depots generally in a sequence. So we measure the depth of the fat with
ultrasound.”
Another key indicator of the animal’s health is the condition of its hair. This moose has most of
its hair. They aren’t all so lucky. Some of them have scratched a lot their hair off.
“Rick yesterday saw a calf of one of our cows that was, ‘what’d you say Rick, only 25% hair?’ So
that one’s been rubbing and scratching for a long time. And, of course, when they’re doing that
rubbing and scratching and biting, they’re not foraging, and it can drain them over time.”
The collar has to fit just right. If it’s too loose, a moose can get a foot caught in it. If it’s too
tight, it can bind, especially in the fall mating season when the bulls’ necks get thicker.
“Yep, that looks good.”
(clicking)
Finally the moose is given an antidote to the tranquilizer, pain-killer, and sedative that have kept
him immobile for about half an hour.
“You know, you’ll see his ears twitch, and he’ll start to lift his head,” Delgiudice says. “The
moose are better at getting up than deer typically. They just get up, loosen up a little bit, and
then lope away.”
The moose struggles up, stands for a minute, and then saunters off toward the trees.
That’s moose number five for the day. The team is planning to track 60 moose for five years.
It’ll tell them what kills these moose and what’s keeping the population from growing.
For the Great Lakes Radio Consortium, I’m Stephanie Hemphill, in the Superior National Forest.
Plants and animals that come from overseas sometimes out-compete species that are native to the region. Scientists have long debated what makes the invaders so successful. One hypothesis is that invasive species have fewer natural enemies. New research supports this idea. The Great Lakes Radio Consortium’s Rebecca Williams has details:
Transcript
Plants and animals that come from overseas sometimes out-compete species that are native to the
region. Scientists have long debated what makes the invaders so successful. One hypothesis is
that invasive species have fewer natural enemies. New research supports this idea. The Great
Lakes Radio Consortium’s Rebecca Williams has details:
Invasive animals and plants have fewer parasites and diseases than their native competitors.
That’s according to two new studies published in the journal Nature. In one study, researchers
analyzed parasites of 26 invasive species, including the zebra mussel.
Kevin Lafferty is an author of the study. He says when a foreign species invades a new area, it
leaves most of its parasites behind. He says importing those natural enemies might be a good
way to control invasives.
“There’s still several species, on average, about 13 parasite species back in the introduced
species’ home range, that we could consider for biological control, and of course an important
part of that process is to determine which ones might be safe, in terms of not infecting our native
species.”
A second study looked at nearly 500 plants that have been brought into the U.S. Researchers
found that plants that leave behind the most pathogens are the most likely to become invasive.
For the Great Lakes Radio Consortium, I’m Rebecca Williams.
A soon-to-be-published study concludes that deer overpopulation is having a devastating, long-term impact on forests. The study will come out next month in the journal Ecological Applications. The Great Lakes Radio Consortium’s Cindi Deutschman-Ruiz reports:
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A soon-to-be-published study concludes that deer overpopulation is having a
devastating, long-term impact on forests. The study will come out next month in the
journal Ecological Applications. The Great Lakes Radio Consortium’s Cindi Deutschman-Ruiz reports:
The U.S. Forest Service study was conducted in Pennsylvania’s
Allegheny National Forest. It examined deer densities
ranging from 10 deer to 64 deer per square mile.
As deer increased, tree species declined.
Red maple, sugar maple, white ash, yellow poplar, and
cucumber trees were all adversely affected, and native yew has been practically eradicated in the forest.
Steve Horsley is the study’s co-author. He says the next step is to determine
whether the impact of deer on forests is as great in areas where there
are also housing developments and
farmland.
“Deer tend, for example, when agriculture is in the mix, to
spend their time eating alfalfa and corn,
which have more digestible energy than most of the
plants that you find in the woods.”
Horsely says in the meantime, deer populations must come down,
preferably to less than 20 per square mile. In the Allegheny National Forest, that would mean cutting the
population in half.
For the Great Lakes Radio Consortium, I’m Cindi Deutschman-Ruiz.
Growing numbers of Canada geese are taking up residence in the Midwest instead of migrating in the spring and fall. As the Great Lakes Radio Consortium’s Annie MacDowell reports, government officials and environmental groups are coming up with creative ways to control the growing population:
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Growing numbers of Canada Geese are taking up residence in the Midwest instead of
migrating in the spring and fall. As the Great Lakes Radio Consortium’s Annie
Macdowell reports – government officials and environmental groups are coming up with
creative ways to control the growing population:
Canada geese are becoming a familiar sight on front lawns and in retention ponds across
the Midwest. Goose excrement is a nuisance to residents and bacteria in their feces can
make people sick. Vid Rapsys owns an Illinois franchise of the “Geese Police.” This
special force uses border collies to gather and frighten geese away from private property
without hurting them.
“Tell the dog to come by while it’s in the water. It’s going to swim in a clockwise motion
around the geese in the water. The geese become very unnerved when animals come in
the water after them. Especially animals that looked like they were stalking them on land
and now there’s someone after them in water.”
But Rapsys adds the Border collies don’t offer a permanent solution. Usually the birds
just fly a couple of miles away and settle in someone else’s lawn or pond. More
permanent options involve shaking goose eggs or covering them with vegetable
oil, which stops the growth of the embryo. But aside from killing geese during hunting
season, people are not allowed to harm a Canada goose. They’re protected by a law
written in the early 1900s.
For the Great Lakes Radio Consortium, I’m Annie
MacDowell.
New research is showing that a foreign fish might be aiding the transfer of toxic substances into sportfish populations. The Great Lakes Radio Consortium’s Mark Brush has more:
Transcript
New research is showing that a foreign fish might be aiding the transfer
of toxic substances into sportfish populations. The Great Lakes Radio
Consortium’s Mark Brush has more:
Fish such as bass, trout, and walleye normally eat small native fish.
Now, these large sportfish have learned how to eat a new foreign fish – round
gobies. The gobies can contain toxic pollutants because they feed on
zebra mussels. And because of the way zebra mussels feed they can take up
a lot of pollutants like PCBs.
David Jude is a research scientist at the University of Michigan. He’s
been studying fish living near polluted areas.
“Yes, a lot of sportfish are eating round gobies, we found them in a lot of
predators we looked at in the St. Clair River – perch, brown trout,
walleyes – so the possibility of transferring PCBs into a
lot of the sportfish that people catch is certainly real.”
Jude says he hopes his research will determine ways to control goby
populations where they’ve become a problem.
For the Great Lakes Radio Consortium, I’m Mark Brush.
In recent years, the double-crested cormorant population has
exploded. And commercial fishermen say their business has suffered as a
result. The Great Lakes Radio Consortium’s Karen Kelly reports on a
new federal bill intended to reduce the population of this controversial
bird:
Transcript
The numbers fo bass and perch in the Great Lakes have declined. And many say the cormorant is to
blame. Now New York congressman John McHugh and Minnesota representative Collin Peterson are
proposing a solution. McHugh says they want to give states the option of creating a hunting season
for cormorants.
“The cormorant population is at an all-time high and I think most people who are even a
disppassionate, casual observer can understand that the cormorant population is having a
devastating effect on the fisheries and on the general environment.”
However, the National Audubon Society opposes the measure. They say the birds are protected under
the Migratory bird treaty act. The bill has been sent to the House committee on Resources. McHugh
hopes to have public hearings on the issue next spring.
For the Great Lakes Radio Consortium, I’m Karen Kelly.
The United Nations estimates that sometime between now and October 1999,
the world’s population will reach six billion. This has Great Lakes
Radio Consortium commentator Suzanne Elston wondering – How much is too
many?:
