Archive for the 'Schenley Park' Category

Nov 23 2013

Snow?

First snow in Schenley Park, 12 Nov 2013 (photo by Kate St. John)

As of this writing we know that very cold weather is on its way (18o Sunday night!) but the question of snowfall is still up in the air.  How much will actually stick?

On November 12 the first snow of the season was quite beautiful in Schenley Park.

By now all the leaves have fallen.  Even with snow, this scene would look different if photographed today.

 

(photo by Kate St. John)

 

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Oct 29 2013

More Males Than Females

Summer tanagers, male and female (photos from Wikimedia Commons)

Here’s an amazing fact: Among birds, and especially among declining species, there are more males than females.

It’s always easier to find male birds during breeding bird surveys.  They’re clothed in conspicuous colors and put on a big show, singing and displaying to claim territory and find a mate.  Females are hard to see because they don’t sing, are often cryptically colored, and are secretive around the nest.  Unfortunately it’s not just flashiness that makes males easier to count.  The males are saying “Notice me!” because there aren’t enough females to go around.

In 2007, after reviewing hundreds of scientific papers, ornithologist Dr. Paul Donald concluded that in the vast majority of bird species males outnumber females. This means we can’t extrapolate the size of a breeding population based on the number of males we count.

Why does this happen?  Dr. Donald explained, “It’s not that females are producing more sons than daughters, because at hatching the sex ratio is generally equal. The only possible explanation is that females do not live as long as males. As generations grow older, they become increasingly dominated by males as more females die off.”

Dr. Donald also found that the skewed sex ratio is even worse among endangered birds and at its worst among the rarest species.  He hypothesized this is due to predation of females while on the nest — the double whammy of killing current and future generations at the same time.

Summer tanagers gave me personal experience with this sex ratio phenomenon.

The City of Pittsburgh is outside the summer tanagers’ range so it was quite rare that I found a pair of summer tanagers breeding in Schenley Park in 2011.   I noticed them just after their nest failed (due to a predator) because the male was impossible to ignore.  He was so angry he was shouting at everyone.

He and his lady tried for a second nest but it was too late in the season and they dispersed without success.  The next spring he was back again and easy to see.  He called and displayed, sang and sang, but she never showed up.  He was alone and that made it much easier for everyone to find him.  In 2012 he never had a mate.

This year he didn’t show up at all.   I assume both he and his lady have died.

Fortunately summer tanagers have a very wide range and their population is doing well — they are listed as “Least Concern” –  but they illustrated Dr. Donald’s finding:  Among most bird species there are more males than females.

 

(photos of summer tanagers (male on left, female on right) from Wikimedia Commons)

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Oct 27 2013

Wild Hickory Nuts

Shagbark hickory nuts (photo by Kate St. John)

Here’s something I literally stumbled on in Schenley Park:  shagbark hickory nuts (Carya ovata).

The big round balls, which cradle easily in the palm of my hand, are husk-covered nuts.  They’re green when ripe but turn brown with age (bottom right).  Their four sections naturally come open as the nut ages and sometimes burst when they hit the ground.

I didn’t need any special tools to open the husks, just my fingers.  At first I didn’t realize they were merely husks so I thought it was odd that they didn’t protect the nut but…

The nutshell is another story (center of the photo).  Irregularly shaped and slightly larger than a quarter, I tried to open it by cutting and other gentle means but it was impossible.  The meat inside is reputed to be sweet but I had to destroy the nut to taste it.

Hmmm.  Get out a hammer or hire a squirrel.

I got out the hammer.

The first nut had very shriveled meat inside.  Perhaps it had been attacked by a bug.

The second and third nuts looked promising except that the meats resembled dried Chinese wood ear mushrooms and they tasted like nothing.  (My photo doesn’t do this justice.)

Shagbark hickory nuts, hammered open (photo by Kate St. John)

Either I was doing something wrong — quite possible — or these nuts are not as good as described.

I wonder how many nuts the squirrels spend time opening only to find that the meat inside was not worth it.

(photo by Kate St. John)

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Oct 06 2013

This Is Exciting

Yellow-rumped warbler, October 2013 (photo by Shawn Collins)

They’re here!  The yellow-rumped warblers are back from Canada, on their way to the lower Ohio Valley, the southern U.S., and Central America for the winter.

Yesterday Karyn Delaney and her husband stopped counting at 100 when they found so many yellow-rumps on the Pine Tree Trail at Presque Isle State Park.  Shawn Collins snapped this one in Crawford County.

Like the first snowfall I’m excited to see my first big flock of yellow-rumped warblers in southwestern Pennsylvania.  I haven’t found a flock yet but I think I’ve heard one bird — just one — at Schenley Park.

Unfortunately, just like snow I soon tire of them.  I remember at Magee Marsh last May when my first reaction to seeing yellow-rumped warblers was “Wow!” and within an hour it was “Darn!  Another yellow-rump.”  Their abundance becomes boring.

But I haven’t seen them yet, so for the moment this bird is exciting.

 

(photo by Shawn Collins)

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Oct 05 2013

Beggar-Ticks

Published by under Plants,Schenley Park

Beggar Ticks (photo by Kate St. John)

Related to Spanish needles, most of the Beggar Ticks (Bidens frondosa) in Schenley Park have not yet gone to seed.

When they do they will stick tight to my clothing.  It happens every year.

Click here to see the seeds.

(photo by Kate St. John)

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Oct 03 2013

Acorns Are Connected

Acorns of northern red oak (photo from Wikimedia Commons)

Stop and listen in Schenley Park right now and you’ll hear acorns falling, blue jays calling and squirrels scurrying.   It looks like a bumper crop for acorns in Pittsburgh. (*see p.s.)

Right now the red oaks are putting on a show.  Acorns in the white oak group mature in the same year they flower.  Acorns in the red oak group take two years to mature so those falling now were formed in the hot spring and summer of 2012, influenced by spring precipitation, summer temperatures and the date of the last killing frost.

Though we (usually*) don’t eat them, acorns are a key link in the woodland food web.  They’re so popular that oaks have evolved an abundance-scarcity strategy to throw off their consumers.  In some years acorns are so abundant that the crop overwhelms the acorn-eaters.  In other years they’re so scarce the consumers go hungry.  To further confuse things the oak groups cycle on different schedules: white oaks have a bumper crop in 4-10 years, red oaks on a 3-4 year basis.

Who eats these acorns?  Squirrels and chipmunks are the obvious consumers but plenty of other species depend on them including white-footed and deer mice, blue jays, red-headed woodpeckers and wild turkeys.  Deer, ruffed grouse, bears, mallards and wood ducks eat acorns, too.

The bumper crops have a ripple effect.  A 24-year study, headed by Clotfelter and Pedersen in the southern Appalachian Mountains of Virginia, followed the effects of acorn crops on rodent abundance, raptor abundance and the nesting success of ground-nesting birds.  They focused on white-footed mice, deer mice and dark-eyed juncoes and found these amazing acorn effects:

  • The population of white-footed and deer mice increases in the year after a bumper crop of acorns.
  • Rodents attract predators so the raptor population increases.
  • Too many rodents and raptors causes junco nest failure due to predation on eggs, nestlings and birds.
  • Mice eat gypsy moths so the gypsy moth population drops.
  • The number of ticks increases as white-footed mice and deer increase.

And then, this information from PLOS links acorns to Lyme disease:  Lyme disease increases predictably two years after an acorn bumper crop because white-footed mice are a main reservoir for the Borrelia burgdorferi bacteria.

Don’t blame the acorns.

Everything is connected to everything else.

 

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

*p.s. Is this a bumper crop year?  I wrote about acorns because I’ve been dodging them in Schenley Park as they fall, but not all the trees are prolific.  Hmm….

*”We don’t usually eat acorns”:   Well, we can … after a lot of work.  See kc’s comment!

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Aug 22 2013

Now Blooming: White Wood Aster

Published by under Plants,Schenley Park

White wood aster in Schenley Park (photo by Kate St. John)

If you wait long enough mysteries reveal themselves.

In April 2012 I displayed this photo of squawroot and asked readers the identity of the green leaf on the left side of the picture.  I thought it might be an invasive species.

Squawroot in Schenley Park, 2 April 2012 (photo by Kate St. John)

Mark Bowers and Loree Speedy answered it was probably White wood aster (Eurybia divaricata) which grows in large patches and therefore might look invasive, though it’s not.

Last week I finally put the lonely leaf and its flower together when I found the asters blooming in the same place where the leaves appear in the spring.

And yes it was in patches, small and large.  Small above, large below, in Schenley Park.

Patch of White wood aster in Schenley Park (photo by Kate St. John)

Mystery solved.   …Unless I was fooled again.

 

(photos by Kate St. John)

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Aug 20 2013

Are My Ears Ringing?

iBroad-winged tree cricket, Oecanthus latipennis (phoito from Wikimedia Commons)

This month as I enter Schenley Park and walk up tree-lined Greenfield Road I begin to worry.  With the sound of the expressway on my left and street traffic on my right my ears are overloaded with an additional high-pitched noise.   Are my ears ringing?

I experiment by looking up while listening.  It’s worse.  I plug my ears.  It’s a little better.  The sound of traffic makes it hard to pick out.  What is that high-pitched whirring sound?

August is bug season so I’ve come to the conclusion that the sound is tree crickets, probably one of these (click here).  Maybe the Four-spotted tree cricket (Oecanthus quadripunctatus) who sings day and night and is common along roadsides.

To give you an idea of what I’m hearing, click here for the four-spotted tree cricket and a video with his song.  (The video repeats with a pause at the end.  The sound on Greenfield Road never pauses, there are so many.)

I would try to find these insects but all the online sources say they’re very hard to see — and that’s coming from the experts!  So I’m accepting this as the song of tree crickets and resting assured that my hearing is not in danger.

For more information on tree crickets I recommend this website: Tree Crickets Sweet Sounds of Summer by Nancy Collins at www.oecanthinae.com where you can find close-up photos, songs and videos.

 

p.s.  In settings with less background noise I’ve noticed the tree crickets are in full force this week.

(photo of a broad-winged tree cricket (NOT a four-spotted tree cricket) from Wikimedia Commons.  Click on the image to see the original)

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Aug 08 2013

Experiments with Jewelweed

Published by under Plants,Schenley Park

Jewelweed jewels (photo by Kate St. John)

Tuesday dawned cool and clear with patchy morning fog and lots of dew.  As I walked to work through Schenley Park I noticed that the jewelweed leaves were dripping with tiny round jewels.

Jewelweed gets its name from the way water beads up on top of the leaves but I’d never before seen jewels drip from the tips so I took a picture.  Then I experimented.

What would happen if I touched a jewel?

It came off on my finger and stayed in its rounded jewel form.  It wasn’t pure water.  It didn’t roll off.
Jewel on my fingertip (photo by Kate St. John)

 

While I was experimenting with these tiny drops Art Schiavo, an avid birder from Hershey, PA, was thinking about jewelweed too (amazing coincidence!) and sent me this message:

“I’m sure you know that jewelweed is in the Impatiens Genus.  I’m also fairly certain you know that its medicinal value is insect bite, stinging nettle exposure, and poison ivy relief, but did you know that the seeds are edible and taste similar to sunflower seeds?”

Wow.  I had no idea you could eat the seeds.  A little investigation uncovered this document that explains which parts of the plant are edible and how to cook them.  There’s no need to cook the seeds but good luck catching them when the casing pops.

More experiments ahead!

 

(photos by Kate St. John)

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Jul 30 2013

Oak Wilt Strikes Again

Published by under Schenley Park,Trees

Oak wilt in Schenley Park, 5 July 2013 (photo by Kate St. John)

I love trees so much that I jump at the chance to learn more about them.

Back in February 2011 I learned about the threats facing 60% of our city park trees when the Pittsburgh Parks Conservancy presented a public event called Preserving Pittsburgh’s Trees: Action and Recovery.   I was already familiar with emerald ash borer since I first saw it in Schenley in May 2010 but I learned about something I’d never seen before: oak wilt.

While Schenley Park had been coping with the death of all its ash trees, the other three big parks — Frick, Highland and Riverview — had experienced oak wilt as well.

Oak wilt is caused by a fungus that doesn’t spread easily but can kill a tree in 30 days.  The fungus travels in the oak’s vascular system and when the tree detects it it blocks those vessels.  The blockage kills the tree. It’s the arboreal equivalent of a stroke.  Watch the 13 minute video here to see how this happens.

After the conference I began to watch Schenley’s oaks with new interest.  Two years passed.  Early this month I could tell something wasn’t right at Prospect Circle.  I emailed this and other photos to Phil Gruszka, Director of Park Management and Maintenance at the Pittsburgh Parks Conservancy, and he confirmed that oak wilt had struck again.  He also started the ball rolling to eradicate it.

Fortunately the fungus spreads slowly and that’s the key to stopping it.  It’s either carried into an open wound by sap-eating beetles (this is harder than you think) or it travels from oak to oak via root grafts.  Amazingly, the roots of adjacent oaks graft to each other when they touch underground.  In a pure oak stand they become one huge vascular system.

There is no cure but future deaths can be prevented by cutting down the affected trees, trenching the perimeter to prevent uninfected roots from entering the danger zone, and medically treating the oaks just outside the perimeter.

In the not too distant future a large patch of dead and dying oaks will be chopped down at Prospect Circle.  This will look ugly at first but will save all the other beautiful oaks along the road and hillside.

For more information about oak wilt, read these Pittsburgh Parks Conservancy blogs about the episode in our parks in 2010:

 

(photo of the oak wilt trees in Schenley Park, July 2013, by Kate St. John)

 

p.s. Learn more about the trees in our city parks at this link on the Pittsburgh Parks Conservancy website.

UPDATE on 18 October 2013 from the Pittsburgh Parks Conservancy –> click here.

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