Today, three scenes of raptors in autumn.
Above, a peregrine falcon flies over the Rocky River. This photo of Hillary, who nested at the Hilliard Road Bridge in Rocky River, Ohio, was taken by Chad+Chris Saladin prior to 2011.
A bald eagle ascends at Glade Dam Lake, Butler County, October 2017. Photo by Steve Gosser.
A red-tailed hawk migrates south past the Allegheny Front Hawk Watch, October 2012. Photo by Steve Gosser.
(photos by Chad+Chris Saladin and Steve Gosser)
1 October 2017
Out in the woods, sometimes dead but often alive, you’ll find a large old tree surrounded by a younger forest. Its branches reach out as if the younger trees weren’t there. It’s called a “wolf tree.”
Wolf trees are much older than the woods around them. They were the last tree left after the original forest was cleared to make a farm. While the farm was active the wolf tree stood alone in a field, providing shade for people and animals. After the farm was abandoned the forest regrew around the ancient tree.
This wolf tree at Cedar Creek Park in Westmoreland County was probably part of the old Greenwood family farm. The tree died years ago but yet it stands, a gnarled reminder that western Pennsylvania has been through many changes.
See pictures of live wolf trees and read more about them in this article in American Forests magazine: Wolf Trees: Elders Of The Eastern Forest
(photo by Kate St.John)
In the spring we saw tents in the trees. Now we see webs. Though similar in concept, the structures aren’t made by the same species.
The springtime tent, located in the crotch of a tree, is made by eastern tent caterpillars (Malacosoma americanum) who emerge from their tent to eat young leaves as they unfurl. The webs, located on the branches, are made by fall webworms (Hyphantria cunea) who hide in the web and eat leaves that will fall off in a month or two.
Since late summer female moths have been laying egg masses on deciduous trees.
After a week the eggs hatch into tiny caterpillars who build a web to completely enclose themselves and their food. As they eat, they build the web larger to enclose more leaves.
Fall webworms avoid coming out of the web until they’re ready to pupate. Then they hide their cocoons under flaps of bark to overwinter and emerge next year.
Though the webs look ugly they don’t harm the trees because the leaves will drop soon anyway.
See webworms in action in the video above from The Capitol Naturalist in D.C. Read more in this vintage article from 2011: Coming Soon To A Tree Near You
(photo of fall webworm moth from Wikimedia Commons; click on the image to see the original)
24 July 2017
Last week Pittsburgh Today published a brief article about ecosystem health in the Pittsburgh region. One of their points caught my eye: Pileated woodpeckers (Dryocopus pileatus) have made a big comeback in our area.
I’ve noticed this too. During Pittsburgh’s 2016 Christmas Bird Count last December, many of us found pileated woodpeckers — so much so that Audubon’s summary of the count included this remark: “Pileated Woodpecker was reported at a higher than expected number. 48 individuals represents a new high count for Pittsburgh. ”
On the same day as Pittsburgh Today’s article, I also received an email from Tree Pittsburgh with news about a project this fall to replace ash trees lost to emerald ash borer (read more here.)
Without intending it, the topics are related. My hunch is that we have more pileated woodpeckers in Pittsburgh because we have more under-the-bark insects and more dead and dying ash trees, suitable for nesting, since the emerald ash borer came to town 10 years ago.
Woodpeckers are doing really well. It’s the only bright spot in the emerald ash borer plague.
(photo credits: Pileated woodpecker by Chuck Tague. Dead ash tree with pileated woodpecker hole by Kate St. John)
11 May 2017
On Throw Back Thursday:
In May we see white tents in the trees made by some incredibly social caterpillars.
“Social” caterpillars? Find out more in this vintage article from 2009:
(photo by Marcy Cunkelman)
When a wind storm blew down a tuliptree branch in Oakland it gave me an opportunity to look at the flowers.
Tuliptrees (Liriodendron tulipifera) are sometimes called “tulip poplars” but they’re actually in the magnolia family. They’re one of the tallest trees in North America — up to 160 feet — and by the time they’re old enough to bloom at age fifteen they have no branches in the first 80-100 feet so we rarely see their flowers.
Like magnolias, tuliptree flowers are showy and attractive to bees — so attractive that they’re considered one of our major honey plants.
Here’s a closeup of the flower.
The petals are called “tepals” because they’re combined sepals+petals, the ancestral form of flowers.
Notice that they’re orange on both sides.
Why orange? Bees can’t see red so why do the flowers have orange accents? Are the flowers hoping for hummingbirds?
(photos by Kate St. John)
Are you sneezing yet?
It’s a busy week for trees in southwestern Pennsylvania as they open flowers and unfurl new leaves.
In Schenley Park the trees are flowering everywhere, from insect pollinated redbuds (pink above) to wind pollinated sugar maples (yellow at top) and hophornbeams (below).
Last weekend it was so dry that pollen coated my car and made my throat and eyes itch … and this was before the oaks had bloomed! (Pollen note: Both oaks and pines are wind pollinated. Southwestern PA has an oak-hickory forest with few pines.)
Other busy trees include the bursting buds of hawthorns and hickories. …
… and new leaves on yellow buckeyes.
The city is a heat island so Schenley Park’s trees are ahead of the surrounding area. Our red oak buds burst yesterday so you can expect several busy weeks ahead for trees in southwestern Pennsylvania.
Are you sneezing yet?
(photos by Kate St. John)
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Spend time today to see spring’s beauty. A reminder from A. E. Housman.
Loveliest of trees
Loveliest of trees, the cherry now
Is hung with bloom along the bough,
And stands about the woodland ride
Wearing white for Eastertide.
Now, of my threescore years and ten,
Twenty will not come again,
And take from seventy springs a score,
It only leaves me fifty more.
And since to look at things in bloom
Fifty springs are little room,
About the woodlands I will go
To see the cherry hung with snow.
A. E. Housman
(poem: The Loveliest of Trees by A. E. Housman (1859-1936), #II from “A Shropshire Lad“
photo: from Wikimedia Commons. Click on the image to see the original)
The ground has thawed, the shad are running, and across the hillsides there’s white lace among bare trees.
Downy serviceberry (Amelanchier arborea) is one of the first wild trees to bloom in eastern North America. At 30 feet tall with smooth gray bark, it opens its curly white flowers in early spring. The tree stands out against the gray backdrop of the hills in April but we don’t notice it in summer. The birds do, though, because its reddish-purple berries are a favorite food.
Serviceberries have a wealth of common names. On the eastern seaboard they bloom when a special fish, the American shad (Alosa sapidissima), swims upstream to spawn. In that region it’s called a shadbush.
In Appalachia the serviceberries bloom when the ground has thawed enough to bury the dead and hold a funeral service. Where the word service is pronounced “sarvis,” it’s called a sarvisberry.
Though they’re members of the Rose family and have perfect flowers (containing both male and female parts) serviceberries can reproduce asexually and they hybridize freely, crossing and back crossing until it takes an expert to identify them. Even then there are disagreements. David Sibley’s Guide to Trees points out that the number of species has ranged from 3 to 25; pegged at 16 when the book was published. Downy serviceberry is one of them.
In Schenley Park I was able to reach a low branch and photograph the flowers. This specimen is a cultivated variety, recently planted, so I can’t identify it for sure.
But it can show you why one species has the downy name.
Downy serviceberry refers to the soft hairs on the back of its young leaves. The hairs disappear as the leaves get older.
Do you think this cultivated leaf is downy?
Maybe so.
(photos by Kate St. John)
9 April 2017
For five months Pittsburgh’s trees are bare. This month they look lacy.
In April the trees open their tiny flowers and leaves. Sunlight falls through the branches and heats the ground, prompting woodland wildflowers to bloom.
Many trees are still in bud. The redbuds look dark pink because their rosy flowers aren’t open yet.
In a few weeks the trees will be full of leaves. Now’s the time to appreciate their lacy look.
(photo by Kate St. John)