All posts by Kate St. John

The Black Walnut Challenge

Black walnuts just fallen from the tree (photo from Wikimedia Commons)

10 October 2021

Black walnuts are ripe now and falling from the trees. Guarded by a black-staining husk and a very hard shell, getting to the walnut meat is a challenge for humans and squirrels alike.

Humans gather and process in bulk. Squirrels gather and eat one at a time. Humans use tools, squirrels use teeth.

Both of us get walnut stains on our hands. Squirrels also get stains in their mouths.

Stains on the hands after hulling 500 black walnuts (photo from Wikimedia Commons)

For a squirrel, husking a single black walnut takes about 8 minutes (watch 8 minutes here).

Fox squirrel opening a black walnut (photo by Donna Foyle)
Fox squirrel gnawing a black walnut (photo by Donna Foyle)

Opening the shell can take 40 minutes. (See photos and description at How to Open a Black Walnut). While the squirrel is gnawing the shell, you can hear a scratchy sound. Have you heard this sound in the woods? Watch and listen in the video below.

For an individual human it takes 3-4 weeks to gather, husk, clean, dry (3 weeks), and shell black walnuts. It makes sense to do this in bulk as shown in the video below.

Black walnuts are a challenge … so I buy them at the grocery store.

p.s. Read more about black walnuts at the Phipps #bioPGH blog.

(photos from Wikimedia Commons and Donna Foyle)

Early October Beauty

Turtleheads at Westinghouse Memorial, Schenley Park, 4 Oct 2021 (photo by Kate St. John)

9 October 2021

White turtleheads (Chelone glabra) are widely distributed in eastern North America while pink ones (Chelone lyoni) have a narrow range in the Blue Ridge Mountains. These showy flowers were planted at the Westinghouse Memorial in Schenley Park.

Arrow-leaved tearthumb (Persicaria sagittata) has very tiny white flowers enclosed in a pink bud. I used to think the flowers were pink until I examined this one.

Arrow-head leaved tearthumb, Moraine State Park, 6 Oct 2021 (photo by Kate St. John)

Purple passionflower (Passiflora incarnata) is so fancy that it must be tropical, right? Actually, it’s native to the southern U.S. This vine was blooming on 3 October on Phipps Conservatory’s garden fence. Wow!

Passion flower blooming along the fence at Phipps Conservatory, Schenley Park, 3 Oct 2021 (photo by Kate St. John)

Did you know these asters close at night? I didn’t until I saw them opening in after dawn on Friday.

Asters opening when morning light reaches them, Schenley Park, 8 October 2021 (photo by Kate St. John)

And here’s a curiosity that looks like a pinecone, but it’s not. Willow pinecone galls are made by the willow to protect itself from an insect. Inside each gall is the larva of a midge whose mother laid eggs at the tip of the branch. The larva will overwinter here and emerge as an adult in the spring … unless a bird hammers the gall and eats the insect.

Willow pinecone galls, Moraine State Park, 6 Oct 2021 (photo by Kate St. John)

(photos by Kate St. John)

Otter Have a Happy Friday

“And that is the story of how otters made me late for dinner” — Ollie @whalefern

8 October 2021

A week ago Ollie @whalefern was sitting on a fishing dock in a state park in (I think) the Pacific Northwest when seven river otters showed up.

At first the otters played and groomed but soon they fell asleep in a heap. Ollie couldn’t leave the dock without disturbing them. No way!

See Ollie’s story — “How otters made me late for dinner” — and lots of otter antics at this link. Scroll to the top after you click to get to the beginning!

Happy Friday!

(embedded tweet from Ollie @whalefern)

Earthquake At The Nest

Peregrine at 367 Collins during earthquake in Melbourne, Australia, 22 Sept 2021 (screenshot from live stream at 367 Collins)

7 October 2021

The end of September was eventful for the peregrine falcons nesting at 367 Collins in Melbourne, Australia. Just eight days before their eggs hatched a rare earthquake shook the nest.

Large earthquakes are unusual in Australia so it was surprising when a 5.9 magnitude earthquake struck near Mansfield, Victoria at 9:15am on Wednesday 22 Sept 2021(*). It rattled Melbourne 65 miles away.

USGS map of Australia earthquake on 21 Sep 2021, 23:15:53 UTC

When the earthquake began the male peregrine was on the nest incubating four eggs. At first he crouched low but as it continued he jumped up, looked around, and flew away with a wail. Watch him return to the nest in less then two minutes.

Incubation was successful and the chicks hatched on 30 September (watch video here). The “kids” have been growing rapidly ever since, thanks to many feedings. Here’s a recent feeding, Thursday morning 7 Oct 2021 at 7:15am(*).

Watch the Melbourne peregrines live on YouTube at 367 Collins Falcons.

When you do, keep in mind the large time zone difference between Melbourne and Pittsburgh. The feeding shown above occurred in Pittsburgh at 4:15pm on Wednesday.

(*) indicates date & time is local to Melbourne, Australia.

(screenshot from live stream at 367 Collins, videos embedded from YouTube)

Better Birds Desired

Lewis’s woodpecker (photo from Wikimedia Commons)

6 October 2021

In early October it’s easy to find pigeons, red-bellied woodpeckers, northern flickers, blue jays and chickadees in Pittsburgh. Ho hum! I wish for better birds.

At Jackson Lake in Los Angeles County, California last Sunday, there were similar but more interesting species. Here’s a sampling from Ted Keyel’s eBird checklist.

Instead of rock pigeons there were band-tailed pigeons (Patagioenas fasciata), North America’s largest wild pigeon.

Band-tailed pigeons in southern California (photo from Wikimedia Commons)

Instead of red-bellied woodpeckers (Melanerpes carolinus) there were two other Melanerpes. A flock of 40-60 migrating Lewis’s woodpeckers (Melanerpes lewis) …

Lewis’s woodpecker from the Crossley ID Guide via Wikimedia Commons

… and six acorn woodpeckers (Melanerpes formicivorus).

Acorn woodpecker (photo from Wikimedia Commons)

We have northern flickers in Pittsburgh but they are yellow-shafted (click here to see). In California northern flickers (Colaptes auratus) are red-shafted. Wow!

Northern flicker, red-shafted (photo from Wikimedia Commons)

Instead of blue jays California has Steller’s jays (Cyanocitta stelleri).

Steller’s jay (photo from Wikimedia Commons)

And instead of black-capped or Carolina chickadees they have mountain chickadees (Poecile gambeli).

Mountain chickadee (photo from Wikimedia Commons)

These are much better birds!

Note: Ted posted photos on his checklist but I do not yet have permission to use them so these are from Wikimedia Commons. Click here to see Ted’s photos.

(photos from Wikimedia Commons; click on the captions to see the originals)

Foggy Morning

Fog on spider webs (photo by Kate St. John)

5 October 2021, 8:45am

It’s foggy this morning in Pittsburgh as it has been for several days. On Saturday, heavy dew gleamed at Frick Park and laced the spider webs with beads of moisture.

Foggy morning with dew at Frick Park, 2 October 2021 (photo by Kate St. John)

Today the temperature is warm enough under the trees that there is no fog beneath them though there is plenty above.

Foggy morning in Pittsburgh; no fog beneath the trees, 5 October 2021 (photo by Kate St. John)

On Friday at Schenley Park we could see at ground level but fog above the trees made the sun look like a moon under the arch of the Panther Hollow Bridge.

Sun rising in fog just below the Panther Hollow Bridge, Schnley Park, 1 October 2021 (photo by Kate St. John)

When the fog cleared, the Cathedral of Learning emerged as from a magical kingdom.

Fog clearing in front of the Cathedral of Learning, 1 October 2021 (photo by Kate St. John

Today the fog has intensified in the last hour, no birds are stirring in the trees and Ecco is waiting at the Cathedral of Learning to start his day.

Ecco waits at the green perch, 5 October 2021 (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

(photos by Kate St. John & from the National Aviary snapshot camera at Univ of Pittsburgh)

Birds With Teeth?

Ostrich face (photo from Wikimedia Commons)

4 October 2021

Teeth are so important that every toothless animal today is descended from ancestors that had them. This includes anteaters, baleen whales, pangolins, turtles, and birds.

Giant anteater with his snout in an ant hole (photo from Wikimedia Commons)

The ancestors of birds were theropod dinosaurs. They definitely had teeth.

Velociraptor, a theropod ancestor of birds (image from Wikimedia Commons)
Tyrannosaurus rex, skeletal head (photo from Wikimedia Commons)

Then about 116 million years ago a common ancestor of all birds developed genetic mutations that inactivated the genes for tooth formation. Eventually birds’ teeth disappeared, replaced by horn-like beaks.

There are probably several reasons why teeth disappeared but the main one is this: In order to fly well it’s important to reduce excess body weight. Bones and teeth are heavy so over time birds evolved hollow bones and toothless beaks. They compensate for the lack of teeth by chewing food in their gizzards.

American robin taking flight (photo from Wikimedia Commons)

They also compensated by using their beaks as multi-purpose tools to grasp, twist, pry, crack open shells, and sever tendons.

Each species developed a beak for its lifestyle. A few of them evolved beak modifications that resemble teeth.

Among tooth-billed hummingbirds (Androdon aequatorialis) the males have a “straight bill with a prominent hooked tip and backward-pointing tooth-like serrations on the distal half. The modification is absent on the female bill, and thus may be related to sexual selection,” describes Birds of the World. Perhaps the “teeth” are used for fighting.

Toothbilled hummingbird beak (photo from Wikimedia Commons)

The critically endangered tooth-billed pigeon (Didunculus strigirostris), the national bird of Samoa, has a stout curved bill with a specially toothed lower mandible.

[The bill] is adapted to feed on Wild Mahogany Dysoxylum spp. fruits, although first-year birds apparently cannot do so. These fruits have a tough capsule that it is able to open using its strong bill, removing the flesh using a sawing action with the lower mandible.

Birds of the World, Tooth-billed pigeon account 

If you want to stretch the definition of “teeth” peregrines have two of them. The tomial tooth on each side of the upper beak is used “to kill prey quickly by biting their necks and severing the vertebrae.”

Peregrine falcon showing tomial teeth on upper mandible (photo by Chad+Chris Saladin)

Does that make them birds with teeth? Not really. No dentin, no enamel, and they aren’t using them to chew.

(photos from Wikimedia Commons; click on the captions to see the originals. Peregrine photo by Chad+Chris Saladin)

Inside the Bladdernut

3 October 2021

By October the seed pods of American bladdernut (Staphylea trifolia) are papery brown three-sided puffs.

American bladdernut seed pods, Schenley Park, 1 Oct 2021 (photo by Kate St. John) (background was blurred by portrait mode on my cellphone)

If you peel one apart it becomes three heart-shaped pieces. Each piece may hold one popcorn-like seed. Some pieces may be blank.

Outside of a single bladdernut paper shell (photo by Kate St. John)

Six months ago the bladders began as small dangling flowers less than 1/4 inch long. Notice the three-part leaves that give this native shrub or small tree its trifolia species name.

Flowers much magnified with trifolia leaves, Schenley Park, 17 April 2021 (photo by Kate St. John)

By late July the bladders were green and very puffy. Each section had its own distinct point.

Bladdernut seed pods, 28 July 2020 (photo by Kate St. John)

And then the bladders dried out.

Dried bladdernut, Schenley Park, 3 Oct 2021 (photo by Kate St. John)

American bladdernuts put so much effort into seed pods that it’s surprising to find they can spread by suckers, especially in their favorite habitats of floodplain woods or stream banks in eastern North America.

Range map of American bladdernut (image from Wikimedia Commons)

Visit Schenley Park this month to see the bladdernuts. Pull a seed pod apart and look inside.

(photos by Kate St. John, map from Wikimedia Commons; click on the caption to see the original)

Birding in the Rain

Brown thrasher in a puddle (photo from Wikimedia Commons)

1 October 2021

Pittsburgh has been warm and sunny for a week now and will continue to be pleasant through tomorrow. Then we’ll have to go birding in the rain.

@GetToKnowNature found unexpected beauty in the rain at Sandy Hook, part of the Gateway National Recreation Area in New Jersey that includes the historic Fort Hancock.

Map of Gateway National Recreation Area highlighting Sandy Hook (map from Wikimedia Commons)

The narrow peninsula is a natural stopoff for migrating land birds in inclement weather.

Can you identify the bird songs in the video? The photos provide a hint.

Brown thrasher in the shadows (photo from Wikimedia Commons)

(photos and map from Wikimedia Commons; click on the captions to see the originals)