Category Archives: Schenley Park

Galling

Insects, Schenley Park, Trees

Before the rain began on Saturday I took a walk in Schenley Park to check on the birds.

In addition to a flock of thousands of robins and starlings near Anderson Playground, I found American goldfinches foraging high in a stand of red oak trees.  They seemed to be picking things off the backs of the leaves.  At ground level I heard the sound of raindrops ticking on the dry leaf litter — but it wasn’t raining.  The goldfinches were dropping the shells.

I collected a leaf and took its picture.  Here you see the brown bumps the goldfinches were cracking open.  They look like tiny acorns.

In fact, they’re galls.  When I searched the web to identify them, I learned from the University of Minnesota’s Department of Entomology that there are more than 700 species of gall-forming insects in the US and Canada and 80% of them use oaks (read about it here).

Galls form when tiny insects lay their eggs on live leaves (not these dried brown leaves).  The eggs emit chemicals that stimulate the leaves to grow covers around the eggs.  This protects the larvae until they’re ready to emerge — unless a goldfinch finds them.

Were these galls made by cynipid wasps that are very common on oaks? I thought so at first(*) but …

On 12 Dec 2012, Charley Eiseman at BugTracks corrected my original theory about the galls.  He wrote:  “I believe these are actually among the few oak galls that are not caused by cynipid wasps – they look to me like the work of Polystepha globosa, a midge (Cecidomyiidae).”     This link has more information about the midge.

Thanks to the goldfinches I learned something new.

(photos by Kate St. John)

(*) My original theory was that these were cynipid wasp galls, made by very tiny wasps that are harmless to humans. They lay their eggs on oak leaves.  Each species uses a different site on the oak (root, twig, leaf) and specializes in particular species of oaks. The most amazing cynipid wasp is the one that becomes the jumping oak leaf gall. 

How Stakes Hurt Trees

Schenley Park, Trees, Winter Weeds & Trees


Every day on my way to work I pass this unusual tree in Schenley Park.  It was planted with care, probably more than 40 years ago, when stakes were provided to stabilize the young tree.

But the stakes were never removed.  The tree grew and grew.  The trunk had nowhere to go except outward.  Slowly it engulfed the stakes.

Now this tree’s in a world of hurt.  The rubber guide and wires disappeared long ago.  The stake on the right is still outside the trunk but only a short length of wire is visible (below).

 

The other stake is completely surrounded.  Its top is inside the trunk.

And now the stakes can never be removed.  Though they’ve created a weakness in the trunk, they’re the only support the tree has at that spot so they have to stay.  The damage is done.

It’s too late to save this tree, but you can help others.  Examine staked trees to make sure the guides are not girdling the trunk.  Remove the stakes 1 to 2 years after planting.

For more information see Bartlett’s plant health guide for newly planted trees.

(photos by Kate St. John)

 

The Largest Acorn

Quiz, Schenley Park, Trees

Crack open your field guides!

Today’s quiz is:  Identify this enormous acorn.

Here are some of its characteristics:

  • The acorns are huge, the largest acorns native to North America.  The cups measure 1.25″ across.
  • The outside has a rough diamond pattern with a fringe at the edge.
  • The inside of the cup is smooth.
  • The acorn itself is dark brown at this time of year (see last photo).
  • This oak is in the white oak family.
  • I found them in Schenley Park.

Here’s a close-up of the cups…

…and an acorn inside the cup.

Do you know what species this is?

Leave a comment with your answer.

UPDATE: The answer is bur oak, aka mossy-cup oak (Quercus macrocarpa).

(photos by Kate St. John)

Ubiquitous Human Noise

Musings & News, Schenley Park

Aldo Leopold at his Salk County shack, around 1940 (photo from Univ of Wisconsin Digital Archives)
Aldo Leopold at his Salk County shack, around 1940 (photo courtesy UW Digital Archives)

Imagine listening to birds without the sounds of human machinery in the background.  That’s what our world was like when Aldo Leopold was alive.

In 2012, ecologists Stan Temple and Christopher Bocast from the University of Wisconsin-Madison recreated a 1940 soundscape at Aldo Leopold’s shack in Salk County, Wisconsin. The project was amazing because they didn’t have a recording from Leopold’s time.  Instead they built it from his field notes.

Every morning Aldo Leopold listened to the birds and wrote detailed notes of the songs he heard, where he heard them, and the light levels when the birds first sang.  Using his notes, bird song recordings from the Cornell Lab of Ornithology’s Macauley Library, and newly recorded background sounds from Wisconsin, Temple and Bocast completed the soundscape.

The result is nothing like the place today.  The habitat, birds, and insects have changed and now there’s the constant hum of an interstate less than a mile away.

To get “clean” background sounds Temple and Bocast searched for a quiet place in Wisconsin.  It was very hard to find because, as Temple points out, “in the lower 48 states, there is no place more than 35 kilometers [21.7 miles] from the nearest road, making it nearly impossible to tune out the hum of human activity, even in places designated as wilderness.”

I’m familiar with the problem.  I’m used to noise near my city home but I go to the woods to be quiet and listen to nature.  In the last 15 years I’ve noticed an increase in human-generated sounds in the woods.  It’s impossible to avoid the sound of cars, trucks, trains, motorcycles, airplanes, chain saws, all-terrain vehicles, boats and jet skis.

I don’t like it. Perhaps I’m not alone.

On Sunday I watched a flock of robins in the trees along the Bridle Trail in Schenley Park, directly above the Parkway East.  I tried to locate the birds by sound but could not hear them over the roar of the interstate.

The birds probably couldn’t hear well either. It was more than annoying. It was stressful.

I wonder what they think of ubiquitous human noise.

 

Click on the photo above or on this news article at University of Wisconsin-Madison.  Then scroll down and click on the Soundscape link to hear what Aldo Leopold heard.

 

(photo of Aldo Leopold, courtesy UW Digital Archives.  Click on the image to read the article and listen to the recreated soundscape.)

A Pretty Color But…

Plants & Fungi, Schenley Park

Are you collecting fall foliage to dress up a flower arrangement?

Don’t touch this plant!

Poison ivy is putting on quite a show as it turns beautiful shades of red and orange that highlight its white berries.  Birds love the berries but most humans develop a rash — or worse — from touching the plant.

If you’re not sure how to identify poison ivy, click here for the clues that will spare you an itchy experience.

Leaves of three, let them be!  … even when they’re red.

 

(photo of poison ivy in Schenley Park this week, by Kate St. John)

Haws

Schenley Park, Trees

This week I found a bumper crop of haws littering the sidewalks in Schenley Park.

Haws are the fruit of hawthorn trees:  short trees with low branches, tangled twigs and long, thin, leafless thorns (1″-2″ long).  The thorns are a great clue for identifying the tree.  Haw+thorn.

Hawthorn fruits look like small apples or rose hips, all members of the rose family.  They’re a favorite food of robins and cedar waxwings, and people sometimes preserve or ferment them into jam, jelly, snacks and beverages.  The trees occur worldwide in the northern hemisphere so there are many recipes.

Hawthorn trees are really easy to identify as a genus (Crataegus) but difficult as a species because they hybridize and speciate so often.  At one point botanists listed more than 1,100 species in North America but they’ve since clumped them down to about 100.

The Sibley Guide to Trees says hawthorn species are so similar that identifying them is best left to experts.  However, armed with rudimentary knowledge and my Sibley guide, I’ll go out on a limb for these Schenley trees.

My guess is that they’re a variant of Downy Hawthorn (Crataegus mollis) because the haws are ripening in August and the ripe ones soon fall to the ground.

(photo by Kate St. John)

Taking A Dip

Bird Behavior, Birds of Prey, Schenley Park

  • Immature Red-tailed Hawk, bathing at Schenley Park, August 2012 (by Gregg Diskin)

We’ve all seen robins splashing in water but how many of us have seen a hawk take a bath?

Last Saturday it was already hot when Gregg Diskin took a walk through Schenley Park with his camera.  Near Bartlett Playground he saw a hawk disappear under the bridge so he walked down the path to investigate.  There he found an immature red-tailed hawk taking a dip in the stream.

Bathing is a relatively vulnerable activity so we rarely see adult hawks doing it.  My hunch is that this bird was one of the two immature red-tails who starred in Monday’s blog.  He had almost no fear of people, felt right at home, and continued to bathe while Gregg snapped a series of pictures.

Click on the photo above for a slideshow of the red-tail’s bath.  At the end he has something to say to Gregg.

(photos by Gregg Diskin)

Whatcha Got There?

Birds of Prey, Schenley Park
Juvenile red-tailed hawks in Schenley Park, July 2012 (photo by Jim Funderburgh )

6 August 2012

This spring two red-tailed hawk babies fledged from the Panther Hollow Bridge in Schenley Park.  They’re already as big as their parents but they don’t act grown up.  They’re not wary of humans and they whine when they’re hungry.

At this stage they’re learning how to capture and kill prey with their feet.  They’ve been watching their parents for tips but they always hope their parents will deliver dinner.  Meanwhile the adults are waiting longer to feed them, hoping the kids will take the hint: “Feed yourself!”

The two juveniles are often found together because Little Brother, the younger of the two, follows his big sister at meal times in case she catches something.

In mid-July Jim Funderburgh found the two hawks exploring the park on their own. Little Brother whined but his sister had nothing to give him so he found a mouse-size object and practiced his prey techniques.

In the video he clutches to kill it … but it surprises him.  Yikes!

Whatcha got there, Little Brother?

A pinecone!

(photo and video by Jim Funderburgh)