Archive for the 'Musings & News' Category

Dec 08 2015

Invasive Species: Earthworms!

Robin feeding earthworm to its nestling (photo by William H. Majoros via Wikimedia Commons)

Robin feeding earthworm to nestling (photo by William H. Majoros via Wikimedia Commons)

We’re all familiar with this sweet scene of a robin feeding earthworms to its young, but did you know this worm is non-native and invasive?

It’s true. 10,000 years ago the glaciers killed North America’s native earthworms.  Though there are still some natives in the south they work deeper underground than the European and Asian worms that arrived with immigrants in potted plants, root balls and dry ballast (soil).

Until quite recently I thought earthworms were native. All my life I’ve watched robins yank them out of the soil and seen them on the sidewalk after heavy rain.  Gardeners and composters are happy with them, too, but…

Lumbricus terrestris is an invasive earthworm in North America (photo from Wikimedia Commons)

Lumbricus terrestris is invasive in North America (photo by James Lindsey at Ecology of Commanster, Belgium via Wikimedia Commons)

What’s good for the garden is lousy for North America’s forests. Earthworms churn the soil column and devour leaf litter, invertebrates and fungi that our northern forests rely on. The result is a lack of ground cover and poor regeneration of the trees.

The problems are especially acute at the edge of the earthworm advance around the 45th parallel, Minnesota for example.  Studies have shown this lowly garden friend is responsible for the decline of ovenbirds in northern Midwest forests and the decline of forest orchids. Oh my!

Like the emerald ash borer, we humans have accidentally introduced a species that’s bad for the forest.  The only way to stop it is for us to stop moving worms and soil.  Composters and gardeners take note!  If you’re on the edge of the earthworm advance — in Minnesota or Maine, for instance — don’t buy worms.  (Pittsburgh isn’t on that edge; earthworms have been here a very long time.)

Meanwhile, thank heaven that robins eat them!

Want to learn more? Watch this 10 minute video from the Smithsonian Environmental Research Center.


(robin photo by William Majoros via Wikimedia Commons. Earthworm photo by James Lindsey at Ecology of Commanster, Belgium via Wikimedia Commons.  Click on the images to see the originals)

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Nov 28 2015

Anyone Home?

Published by under Musings & News,Trees

Anyone home? (photo by Kate St. John)

Hole in a sugar maple in Schenley Park (photo by Kate St. John)

When I see a hole like this I wonder if an animal is inside.

In the winter it could be sheltering chickadees or tufted titmice.  If it’s big enough it may hold a squirrel … or something even better.

When you’re in the woods on a cold sunny afternoon, look for tree holes.  You might see an owl peeking out of one.

Anyone home?


(photo by Kate St. John)

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Nov 06 2015

What Happens At A Clearcut?

Tree removal project at Central Catholic, 30 Oct 2015 (photo by Kate St. John)

Before I retired from WQED in September 2014, this was the view outside my window … except there were trees.

Last month contractors removed all the trees on the hillside between CMU’s new Tepper Quad and Central Catholic’s football field.  By the time I saw it a week ago it looked like this.

Hillside denuded by tree removal project at Central Catholic, 30 Oct 2015 (photo by Kate St. John)

To give you an idea of what it used to look like, here’s a view of the remaining trees behind WQED.

Trees remaining on hillside behind WQED, 30 Oct 2015 (photo by Kate St. John)

In the grand scheme of things this was a small woodlot surrounded by parking lots and an astroturf field, host to many invasive species.

Does it matter that humans removed this small landscape?

It does to the animals who lived there.

In the remaining woodlot behind WQED two squirrels fought a territorial battle. The loud one said, “This is mine! You have to leave!” The other cowered but stayed nearby. Probably a refugee.

Winter or a predator will determine who survives.


(photos by Kate St. John)

p.s. Does anyone know whose project this is (CMU or Central Catholic?) and why it was done?

UPDATE:  I haven’t been back to the site for a week but friends confirm that this is a CMU project and that all the trees are gone now.  Every single one.

7 responses so far

Oct 06 2015

Food For The Extinct

The "monkey ball" fruit of the Osage Orange tree (photo from Architect of the Capitol via Wikimedia Commons)

The “monkey ball” fruit of the Osage Orange tree (photo from Architect of the Capitol via Wikimedia Commons)

Why is the Osage orange (Maclura pomifera) “monkey ball” such a prolific fruit when almost nothing eats it?

Why is the avocado seed so large?  (Persea americana)

Open avocado showing huge seed (photo from Wikimedia Commons)

Open avocado showing huge seed (photo from Wikimedia Commons)


Why does the honey locust (Gleditsia triacanthos) have huge thorns on its trunk?  And…

Honeylocust thorns (photo from Wikimedia Commons)

Honeylocust thorns (photo from Wikimedia Commons)

… large seed pods that no one eats?

Honey locust seed pod (photo from Wikimedia Commons)

Honey locust seed pod (photo by Andrew Dunn from Wikimedia Commons)

These fruits are food for giants that are now extinct.

Just 13,000 years ago the Americas were inhabited by mammoths, horses and giant ground sloths whose diet included “monkey balls,” avocados and honey locust pods.  Only a giant could eat such large fruit in one gulp and pass the seeds through its digestive track.

The giant ground sloth (Megatherium) for instance weighed 4 tons (8,000 pounds) and could reach 20 feet up when he put his paw on a tree trunk and stood on his hind legs.  He could also damage the trees so the honey locust evolved big thorns for protection.

Megatherium, extinct ground sloth (illustration from Wikimedia Commons)

Megatherium, extinct ground sloth (illustration from Wikimedia Commons)

He’s been extinct for 10,000 years, but the tree remembers.


For a fun 5-minute video about the fruits that point to missing mammals, watch below.



(photos from Wikimedia Commons. Click on each image to see its original)

Notes and links:

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Oct 02 2015

A Bird In Hand

Published by under Musings & News

Jonathan Nadle with bird in hand at Bird In Hand, PA (photo by Lori Nadle)

Jonathan Nadle with bird in hand (photo by Lori Nadle)

My Tuesday article about hand feeding chickadees (A Bird On The Hand) prompted my friend Jonathan Nadle to send me this photo.

He said it was difficult to find the bird at this location but he was determined not to miss the chance to hold this exceptional species.


(photo by L&J Nadle)

p.s. The man who invented the pink plastic flamingo died last June. Did you know that for 37 years he and his wife always wore matching outfits? Click here to read more.

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Sep 30 2015

Pay Attention To What I Eat

Yellowhammer, male (photo from Wikimedia Commons)

Yellowhammer, male (photo from Wikimedia Commons)

Here’s the story of a great idea that went sour really fast because people didn’t observe bird behavior.

During the 1800’s many Britons emigrated to New Zealand and began farming. As the settlers cleared the forest, New Zealand’s native birds (which are flightless) retreated or became extinct.

Soon insect pests proliferated and the farmers clamored for a solution.  Someone had a bright idea, “I know! Birds eat bugs. Let’s import a bird.”

The Acclimatisation Societies decided to import the yellowhammer (Emberiza citrinella), a sparrow-like Eurasian bird famous for his pretty song.  They lined up dealers in Britain who captured local yellowhammers and shipped them overseas.  New Zealand’s farmers welcomed them with open arms.

It didn’t take long to find out this was a terrible mistake.  The birds ate the crops, not the insects.

Look at his conical bill and you can tell the yellowhammer eats seeds all year long.  In fact, he only supplements his diet with insects during the breeding season.

Soon New Zealanders hated the yellowhammers.  In 1880, only 15 years after the first birds arrived, the last shipment was turned away and sent to Australia.  Farmers hunted, poisoned and raided yellowhammer nests, trying to rid the country of this once welcomed bird but it was too late.  Yellowhammers were firmly established in New Zealand and are widespread today.

They’d have saved a lot of trouble if someone had paid attention to what yellowhammers eat.

Read the full story here at Science Daily.


(photo from Wikimedia Commons. Click on the image to see the original)

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Sep 28 2015

In Case You Missed It: Tick Check!

Lyme Disease incidence in U.S. 2014 (map from

Lyme Disease incidence in U.S. 2014 (map from

In case you missed it on the radio …

Oh no!  That dark blue spot on the map is bad news.  Each microscopic dot represents an incident of Lyme disease in 2014.  Look at western Pennsylvania!

This year Lyme disease came closer to home than ever before. Several friends of mine caught it this summer in Allegheny County, in suburban Pittsburgh.

Do these anecdotes represent a real increase in local Lyme disease?  If yes, what is causing it?  And does it have anything to do with our weather or climate change?

I posted my question on the iSeeChange website (here) and The Allegheny Front‘s Kara Holsopple investigated.  She found out that Lyme disease is increasing in western Pennsylvania and there’s more than one reason for it.  Warmer winters (climate change) do play a part.

Read and hear the story here at:  Tick Check: Why Lyme Disease is on the Rise in Pennsylvania.


(Lyme disease incidence map from  Click on the map to see the large PDF version)

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Sep 22 2015

Undrinkable in Pennsylvania

Undrinkable: acid mine drainage (photo by Kate St. John)

Acid mine drainage in well water (photo by Kate St. John)

Two weeks in Maine where the water is clean re-opened my eyes to something I take for granted in Pennsylvania: some places have orange water.

Perhaps you’ve been to this restroom at the Route 528 boat launch in Moraine State Park.  The restroom is clean but the water is not.  “Notice. Non-potable water. Not for Drinking.”   The metallic smell and orange-stained sinks and toilets make you wonder, “If the water’s that bad, should I use it to wash my hands?”

Coal mining contaminated the ground water here(*).  The orange water is acid mine drainage.  When the coal was removed it exposed pyrite which, when exposed to water, turns into sulfuric acid and iron.  Bad water from old surface and underground mines flows into streams and wells in Pennsylvania’s coal regions.

95% of the acid mine drainage in the U.S. is right in here in western PA, West Virginia, southwestern Virginia, and far western Maryland.  Visitors are shocked by the orange water we’ve come to take for granted.  Pennsylvania has more than 3,000 miles of these polluted streams, a problem too huge for individuals to solve.

The good news is that Pennsylvania stepped in with coal mining laws in the 1960’s that prevent new water contamination and PA Department of Environmental Protection (DEP) can require clean up when an old mine is reopened.  Slowly, the worst water is being treated and improved.

That’s how part of the Conemaugh River turned from orange to clear in Somerset County in 2013.  See before and after pictures and read about the impressive change here on the Allegheny Front.


(photo by Kate St. John)

(*) There are other ways to expose pyrite.  During construction of Interstate-99, excavation and rock-handling on Bald Eagle Ridge exposed pyrite that polluted nearby ground water and Buffalo Run, a high quality stream.  Though the pyrite was known to be there, construction plans ignored it.  It took two years and $83 million to fix the mistake.

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Jul 15 2015

Fossil at Ferncliff

Rock, path, with fossil at Ferncliff (photo by Kate St. John)

Rock with hashmark pattern across it (left to right) at Ferncliff, Ohiopyle (photo by Kate St. John)

Years ago when I first hiked the Ferncliff Trail at Ohiopyle I was puzzled by this pattern on the rock beneath my feet.

In those days there weren’t interpretive signs nearby so I tried to make sense of it as best I could.  I decided it was a motorcycle track, but I couldn’t figure out how the vehicle had gotten there and why it had run from the cliff into the river.

Duh!  Motorcycles don’t leave tracks in rock.  It’s a fossil.

Fossil at Ferncliff Peninsula (photo by Kate St. John)

Fossil at Ferncliff Peninsula (photo by Kate St. John)

This Lepidodendron is one of six kinds of fossils found along the river’s edge now listed on an interpretive sign as: Cordaites leaves, Lepidodendron scale, giant Calamites, Psaronius, a giant dragonfly and Sigillaria.

Though I’ve seen the other ones this is the fossil I like the best.

Lepidodendron was a tree-like plant with scales on its trunk that grew as high as 100 feet tall.

Drawing of Lepidodendron by Eli Heimans, 1911 (image from Wikipedia)

Drawing of Lepidodendron by Eli Heimans, 1911 (image from Wikimedia Commons)

It lived and died in the Carboniferous (coal making) era.  If the tree had fallen in a swamp it would have become peat and then coal, but it happened to fall on sand so the patterns of its scaly trunk were preserved in rock.

Not far away is one of Lepidodendron’s last living relatives: Lycopodium or groundpine. Only 6-12 inches tall, its tiny trunks and branches provide a visual hint of its ancestor’s appearance.

Lycopodium (photo from Wikimedia Commons)

Tree Groundpine, Lycopodium dendroideum (photo from Wikimedia Commons)

The past and present are near each other at Ferncliff Peninsula.


(fossil photos by Kate St. John. Drawing of Lepidodendron and photo of Lycopodium from Wikimedia Commons; click the images see the originals)

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Apr 17 2015

A Happy Merger

Published by under Musings & News

Hoary redpoll and common redpoll at feeder in Alberta, Canada (photo by dfaulder via Wikimedia Commons)

In Cornell Lab of Ornithology‘s eNews I encountered the only case of species “lumping” I’ve ever been glad to see.

Researchers from Cornell Lab’s Fuller Evolutionary Biology Program tested the DNA of 77 hoary and common redpolls and found that hoary redpolls and common redpolls have no differences at all across much of their genomes.  Just to make sure, Nicholas Mason and Scott Taylor examined 235,000 regions of the genome, not just 11, and they tested DNA of the lesser redpoll of Eurasia.  The lesser redpoll is the same as well.

What we’ve been calling three species are merely variations in color and size.  Other species vary, too.  Humans, for instance.

Now that the weight of DNA evidence merges hoary, common and lesser redpolls into one species it’s only a matter of paperwork, review, and voting at the American Ornithologists’ Union to make this official.

I’ll be happy when its done.  I’ve seen common redpolls but not hoary ones, and now I won’t have to go out of my way to find a hoary redpoll unless I’d like to see his beautiful pale feathers.  This simplifies my winter travel plans considerably.

Read more here about the only redpoll in Cornell Lab’s All About Birds blog.


(photo of a (formerly) hoary redpoll at left and common redpoll at right by dfaulder via Wikimedia Commons. Click on the image to see the original)

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