Tag: mice

Mice Morphing at Warp Speed

  • Oliver Pergams used a tiny caliper to measure the mice, tracking changes in size over the years. (Photo by Gabriel Spitzer)

Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much
faster than nearly anyone thought. Gabriel Spitzer has more on those
changes, and how they seem to be linked to humans:

Transcript

Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much
faster than nearly anyone thought. Gabriel Spitzer has more on those
changes, and how they seem to be linked to humans:

Tall Trees Park is a little patch of green in Glenview, Illinois – a
northern suburb of Chicago. About a hundred years ago, a lot of this area
looked a lot like this. It was mostly farms and pasture and forest. And now
of course it’s a lot of strip malls and subdivisions and stuff. And the
population has grown seventyfold. The climate has changed, too. It’s
gotten a little warmer, a little wetter.

And all this has made life a lot different for the northern white-footed
mice who live here. It’s actually not just made life different for the
mice, it’s changed the mice themselves.

That gets back to a guy named Oliver Pergams. He’s an ecologist, and in
the mid-90s, he was looking at deer mice who live on the Channel Islands
off the coast of California. And he was taking these mice and comparing
them to museum samples of the same kind of mice from the same place, but
decades earlier.

“And I found something kind of strange – that the older specimens were
larger than the newer specimens, so they shrunk in size over a period of
about 30 or 40 years.”

That got him wondering if those relatively quick changes are happening in
other places. So years later, now on the faculty at the University of
Illinois at Chicago, he gathered up some of those White Footed Mice from
the Chicago suburbs. And he went to the Field Museum of Natural History…

(sound of a cabinet opening)
… where they have a hundred years of dead mouse specimens stored in
white metal cabinets.

“Here we have trays and trays of the northern white-footed mouse.”

With a tiny caliper, he’d measure their skulls, their feet, the distance
from their eyes to their noses.

“So this one here was collected by Aikley in 1903.”

And he compared mice from before and after 1950.

“Here are some skulls, this one was collected in 1989.”

Lo and behold, these mice had grown: by more than 10% on some measures.

This phenomenon goes way beyond Chicago. Pergams measured more than 1,300
rodents from four different continents – Alaskan lemmings, Mexican
gophers, Filipino rats. Some of them got bigger, some smaller. But across
the world, most of the animals have changed over time spans thought to be
mere evolutionary eyeblinks.

The next step is to figure out why.

“You can’t get in a time machine and go back and look to see what
actually happened. So the next best thing is to see if there’s
associations or correlations with big factors.”

He found the variations correlate with changes in climate and human
population density. The exact reasons aren’t clear – more people might
mean more yummy trash for the mice to eat, for example. That’s going to
take more research to figure out, and these critters might be overdue for
some extra attention.

“One of the questions is, well, why didn’t anybody notice this before?
And I think the answer is, they haven’t looked.”

Larry Heaney curates the Field Museum’s mammal collection. He says
Pergams’s research opens up new questions about how animals respond to
changes driven by humans.

“The implication is, these animals are changing very, very rapidly. So in
a sense, it’s good: they can change. But the other side of the coin is,
they’re having to change.”

Now, the question is, is this happening in other species, too? What about
birds or bugs or plants?

“There’s been this default attitude that if you go to one place and you
capture or you observe animals or plants, that essentially there’s going
to be the same animals or plants 50 years or 100 years later. I don’t
think that’s possible to assume at all. We have to include the fact of
this change in all of our decisions, from ecology to evolutionary biology
to conservation.”

Pergams’s findings show that even the most common creatures have more to
teach us – when we ask the right kinds of questions.

For The Environment Report, I’m Gabriel Spitzer.

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Plastics Chemical Causes Defects

A new study finds low doses of a chemical used in plastics increases developmental
defects in mice. Rebecca Williams reports the study adds to the growing body of
research that has some scientists wondering if there are human health effects:

Transcript

A new study finds low doses of a chemical used in plastics increases developmental
defects in mice. Rebecca Williams reports the study adds to the growing body of
research that has some scientists wondering if there are human health effects:


The chemical’s called bisphenol A. It’s used to make everything from plastic baby bottles
to the lining of food cans.


The researchers exposed pregnant mice to the chemical. They found that the female
babies those mice were carrying were more likely to have eggs with chromosome defects.
So it’s a three-generational effect. Exposure in the pregnant female mouse increases the
likelihood her grandchildren will have defects.


Patricia Hunt is an author of the study, published in the Public Library of Science
Genetics. She notes this is an animal study and humans are more complex:


“But we also need to bear in mind that this is one chemical of many that have these
effects, they can mimic the actions of hormones in the body.”


Hunt says there’s a growing level of concern among scientists that the developing fetus
might be especially sensitive to chemicals that mimic hormones.


For the Environment Report, I’m Rebecca Williams.

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Study: Diet Worsens Air Pollution Effects

A lot of studies have linked air pollution with heart and lung problems. A new study suggests your diet can worsen air pollution’s effects on you. The Great Lakes Radio Consortium’s Michael Leland has more:

Transcript

A lot of studies have linked air pollution with heart and lung
problems. A new study suggests your diet can worsen air pollution’s
effects on you. The Great Lakes Radio Consortium’s Michael Leland
has more:


Every time you inhale, you’re breathing in tiny particles from dust, soot
and smoke. They can increase both the plaque buildup in your arteries,
and the risk of a heart attack or stroke.


Now, a study led by Dr. Lung Chi Chen at New York University’s
School of Medicine says a high fat diet combined with bad air led to a
faster buildup of plaque in the arteries of mice. He says that’s because
air pollution affects lipids – fats – in the blood. It changes their
characteristics, or oxidizes them, which leads to more plaque on artery
walls.


“If the mice are fed with high-fat, then the level of the oxidized
lipid will be higher, because they have more lipid in their blood.”


Dr. Chen says arteries of mice on a high-fat diet and breathing dirty air
were 42-percent blocked. Mice breathing clean air had arteries that were
26-percent blocked.


He hopes the study not only encourages people to eat better, but also
persuades the government to toughen air quality standards.


For the GLRC, I’m Michael Leland.

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A Rare Visit From a Northern Neighbor

  • The Great Gray Owl is a rare sighting south of the U.S.-Canadian border. (Photo by Matt Victoria, Camillus, NY. www.fickity.net)

The Great Gray Owl usually lives deep in the northern forests of Canada. But due to scarce food, thousands of the big owls have drifted south. They’ve drifted into southern Ontario and Quebec, even crossing the border into Minnesota, Wisconsin, and Michigan. Last month, a Great Gray was spotted in New York, the first one documented there in almost a decade. The Great Lakes Radio Consortium’s David Sommerstein was there when it
happened:

Transcript

The Great Gray Owl usually lives deep in the northern forests of Canada. But due to scarce food,
thousands of the big owls have drifted south. They’ve drifted into southern Ontario and Quebec,
even crossing the border into Minnesota, Wisconsin, and Michigan. Last month, a Great Gray
was spotted in New York, the first one documented there in almost a decade. The Great Lakes
Radio Consortium’s David Sommerstein was there when it happened:


Ornithologist Gerry Smith had invited me to see some of the best raptor habitat in northern New
York. We took off in his cluttered Saturn wagon.


“Here we go!…” (sound of engine turning on)


Gerry wears a beat up canvas hat, green sweatshirt, and always has one hand on his binoculars.
He started birdwatching when he was 13 as a sort of therapy.


“My father passed away when I was 15, but he was terminally ill, and I needed an escape, you
know, obviously as a 13 year-old kid I didn’t know that, but I got hooked, and the rest, as they
say, is history.”


More than 40 years later, he’s never had a job not related to birds. And he’s in his element
cruising the back roads of Upstate New York.


These farm fields are near the St. Lawrence River. They’re ideal for hawks and owls. They’re
grassy with occasional tree stands. And they don’t get as much snow as other parts of the state.
So birds can snag the mice and voles they live on all winter long.


In no time, Gerry’s spotting raptors. There’s a hawk perched in a twisted elm…


“Yep, it’s a Red-tailed Hawk and I think it’s got prey because it’s bending down like it’s eating.”


A rough-legged hawk soars above us, black and white plumage glowing in the sun.


“The bird was just lofting along.”


A Short-eared Owl glides past a farmhouse.


“Look how that is flying. It’s flying like a big fruit bat. Cutting left across the hay bales, coming
toward the house, above the house now, and drifting left.”


Smith’s also seen a snowy owl this year. But still no sign of the Great Gray owl.


The Great Gray usually lives in the far northern forests of Canada. But this year it has flown
south to the upper Great Lakes region by the thousands. Conservation biologist Jim Duncan is a
Great Gray Owl expert with the province of Manitoba. He says the phenomenon happens
cyclically, when the Great Gray’s main food source – the meadow vole – becomes scarce.


“It’s a regular migration. It’s like a robin migrating in response to food availability, except in the
case of the Great Gray Owl, it’s a longer period of time. It’s three to five years.”


Gerry Smith’s still waiting for the Great Gray in New York. It’s been spotted just across the St.
Lawrence River in Canada.


“There’s a single Great Gray Owl on Amherst Island, but not one, as far as we know, has made it
into northern New York despite the fact that a whole lot of us have been looking.”


Now, I know you’re going to call that easy foreshadowing. But believe it or not, just an hour
later, Gerry pulls the car over, grabs his binoculars, and peers at something big perched on a tree.


“We have the first Great Gray Owl that’s made it across the border. I’ll be a son of a gun. That is
so…Now I’m very enthusiastic. Hey, I’m gonna set up my scope.”


While Gerry unpacks the telescope, a raven flies to a branch just above the owl and tries to scare
it away. Birders call it “mobbing.”


“Now don’t you mob that owl, you fiend. I think that’s what he’s thinking of doing. Watch this.”


The owl holds its ground, and Gerry gets it in the telescope’s sights.


“That is so cool. It’s not facing us, it’s back is to us, but take a look, that shape is very
distinctive.”


It’s slate gray with some brown and white, round head, stocky body, as big or bigger than the
raven.


“This has been…oh, the owl just hooted. It’s a very low guttural hoot, something like a horned
owl, only deeper.”


Just then, the owl’s finally had enough. It takes flight and drifts slow and low to a stand of trees,
likely its roost. Gerry jots down the GPS coordinates and we get back in the car.


“Well, sir, we’ll finish the route and head back, but we have had undoubtedly the high point of
the day. That’s the high point of my winter.”


This Great Gray Owl migration is the biggest on record. Biologist Jim Duncan says it’s a chance
for all eager birders to help science.


“People have a real opportunity to contribute to our knowledge of the species, be they farmers,
housewives, commuters. They don’t have to be scientists.”


You do have to be respectful, though, if you want to report Great Gray sightings to wildlife
officials. Stay off private land, don’t make noise, and keep your distance. And enjoy a rare
opportunity to see a Great Gray visitor from the North.


For the GLRC, I’m David Sommerstein.

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STUDY FINDS PDBEs IN HOUSEHOLD DUST

  • Babies and children are frequently in contact with dust. Some scientists worry that potentially-harmful chemicals found in household dust will result in negative health effects. (Photo by Jason Sellers)

Chemicals that are suspected of being hazardous to human health are being found in household dust. The chemicals are flame retardants used in everything from carpet padding to TV sets. The Great Lakes Radio Consortium’s Mark Brush has more:

Transcript

Chemicals that are suspected of being hazardous to human health
are being found in household dust. The chemicals are flame retardants
used in everything from carpet padding to TV sets. The Great Lakes Radio
Consortium’s Mark Brush has more:


The chemicals are known as poly-brominated-diphenyl-ethers, or PBDEs.
Scientists already knew that these flame retardant chemicals where found in
food. Now researchers are finding the chemicals, in household dust.


Heather Stapleton is a research chemist at the National Institute of
Standards and Technology. She authored a study recently published by the
American Chemical Society.


“I went out and collected some house dust samples from areas within the
Washington D.C. metropolitan area, and brought these samples back to the lab
and just did a preliminary measurement looking at PBDE’s in the house dust
samples and found surprisingly high levels in the house dust.”


Researchers are most concerned about how the chemicals affect developing
babies. Babies have more contact with household dust than the rest of us.
The chemicals have been found to cause developmental and nervous system
damage in rats and mice.


For the GLRC, I’m Mark Brush.

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Owls Crossing Border Into U.S. For Food

  • Owls have been migrating from Canada to the U.S. in search of easy prey. (Photo by Florian Engels)

Owls have been moving from their native habitat in Canada into the United States. Researchers say the number of owls making the trip is unprecedented. The Great Lakes Radio Consortium’s Christina Shockley
reports:

Transcript

Candian owls have been moving from their native habitat into the United States, including MN, WI, MI, and IA. Researchers say the number of owls making the trip is unprecedented. The Great Lakes Radio Consortium’s Christina Shockley reports:


The Great Gray Boreal , northern hawk, and snow owls live in
the upper reaches of Canada. But hundreds of owls have been flying into the U.S. in search of food. The small mammals they prey on in their native range, like mice, voles, and lemmings, are in the midst of a population crash. Susan Foote-Martin is with the Wisconsin Department of Natural Resources. She says it’s common for small-mammal populations to rise and fall. So, even though the owls expend a lot of energy to get here, their stay is temporary.


“They’ll definitely move back. They’re only down here because the population of the animals they eat are down. But there’s also another consideration, and that’s deep snow cover in the areas where they normally live.”


Foote-Martin says the owls have a hard time catching their prey because they burrow deep into the snow. She says if the owls continue to fly into the U.S. over several years, it could signal a problem in their native habitats.


For the Great Lakes Radio Consortium, I’m Christina Shockley.

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Small Forest Patches Breed Disease

Chopping down trees for subdivisions and farm fields isn’t just bad for forests. It can also hurt people. According to new research, small patches of woodlands breed more ticks with Lyme disease. The Great Lakes Radio Consortium’s David Sommerstein reports:

Transcript

Chopping down trees for subdivisions and farm fields isn’t just bad for
forests. It can also hurt people. According to new research, small
patches of woodlands breed more ticks with Lyme disease. The
Great Lakes Radio Consortium’s David Sommerstein reports:


Felicia Keesing, a biology professor at Bard College, wanted to know
where people ran the greatest risk of getting Lyme disease, an illness
spread by ticks. She knew Lyme disease-bearing ticks are carried mostly
by the white footed mouse. And she knew that kind of mouse thrives in
small chunks of forest.


That’s because its predators need larger woods to live and have
moved away. So Keesing compared forest chunks of different sizes for
tick populations. She found a lot more ticks with Lyme disease in small
forests boxed in by houses or farmland.


“On average about seven times as likely to encounter an infected tick in a patch of woods
smaller than five acres.”


Keesing says the results send a clear message to town and village zoning boards
weighing development issues. They should do everything they can to prevent the
fragmentation of forests.


Keesing says her research doesn’t suggest small lots should be cut down altogether. But
new development could be better planned to reduce the risk of Lyme disease.


For the Great Lakes Radio Consortium, I’m David Sommerstein.

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