It’s hard to take a bad picture of an American red squirrel (Tamiasciurus hudsonicus). When they pose they look so cute that it’s hard to believe they are asocial, combative and confrontational.
Though they rarely encounter each other — perhaps for their own safety — red squirrels fight when there’s more than one. Most of their battles are a lot of shouting and chasing while the resident squirrel defends his territory.
Defending the midden (food store) is a matter of survival that’s learned in the first year of life. Juvenile red squirrels must find a territory and midden before their first winter or they won’t make it to next spring. Only 22% survive to one year old.
For a few, just 15%, their mothers bequeath them a territory but it still has to be defended. The red squirrels who survive are the most confrontational.
(photos from Wikimedia Commons; click on the captions to see the originals)
Les Leighton had his camera set up at Canada’s Vancouver harbor when a drama played out in front of him. A gull zipped by with both a bald eagle and peregrine falcon pursuing it in flight. What was it about that gull that attracted two predators at the same time?
Watch the chase and notice the difference between the eagle’s and peregrine’s hunting techniques. Why did both of them give up?
Peregrine at the California Avenue Bridge (vicinity of McKees Rocks Bridge), 23 March 2022 (photo by Jeff Cieslak)
28 March 2022
Since my last update on 14 March a Big Thank You goes out to everyone who went looking for peregrines in Southwestern PA, especially to Jeff Cieslak, Dave Brooke and Dana Nesiti. Jeff’s photo, above, has a second message. If you ever doubted the sorry condition of Pittsburgh’s bridges take a look at the underside of the California Avenue Bridge. Yikes!
At every site except Speers/Belle Vernon at least one peregrine has been seen this month. At sites with eggs it’s common to see only one bird. (Click here for a regional map of these sites.)
From March 18 to 30 Morela laid 5 eggs (24-hour clock matches the falconcam).
3/18/2022, 08:31
3/20/2022, 20:09 (approx guess)
3/23/2022, 04:40 (approx)
3/26/2022, 06:32
3/30/2022, 19:08
The overnight egg-times were hard to determine but her 4th egg was easy to see just before dawn. After the 4th she resumed incubation immediately.
I believe that incubation began on 23 March so we can expect Hatch Day on or about 26 April 2022. Watch the nest “live” on the National Aviary falconcam.
Downtown Pittsburgh:
Downtown peregrine at nest on Third Avenue, 23 March 2022 (photo by Jeff Cieslak)
From the top of Mt Washington on 23 March 2022 Jeff Cieslak photographed a peregrine on the nest ledge at Third Avenue Downtown. The pair has not been seen simultaneously since 17 March.
Railroad bridge over the Ohio River from Monaca to Beaver (photo by Kate St.John)
Dante Zuccaro now reports a single peregrine almost every day, seen from the mouth of the Beaver River, most recently on 27 March.
Ambridge-Aliquippa Bridge, Ohio River:
Ambridge Bridge with a peregrine on top, 20 Feb 2020 (photo by Kate St. John)
No news since 8 March. If you’re in the vicinity, please take a look.
Sewickley Bridge, Ohio River:
Peregrine on the Sewickley Bridge, 27 March 2022 (photo by Jeff Cieslak)
After frequently seeing both peregrines at the Sewickley Bridge Jeff Cieslak found only one on 27 March. I’m encouraged that this bird is perched on the pier rather than the superstructure since the underside of the bridge is a much safer place for youngsters. Perhaps they have eggs in a nest under the bridge.
McKees Rocks Bridge / Ohio River Blvd, Ohio River:
Peregrine on the smokestack near McKees Rocks Bridge, 22 March 2022 (photo by Jeff Cieslak)
On 22 March Jeff Cieslak saw a peregrine perched near Alcosan (which is near the McKees Rocks Bridge) but could not figure out where it came from. When it flew he followed it as best he could and returned the next day to investigate.
On 23 March he found a peregrine at the Ohio River Blvd bridge (below) which flew to the California Avenue bridge (shown at top). Perhaps this pair is nesting in the area of the McKees Rocks Bridge but not on it. Meanwhile, did you know that the decrepit California Ave bridge (at top) is rated in “fair” condition? Hmmm!
Peregrine at Ohio River Blvd Bridge, 23 March 2022 (photo by Jeff Cieslak)
Westinghouse Bridge, Turtle Creek:
Male peregrine comes in for a landing at Westinghouse Bridge, 26 March 2022 (photo by Dana Nesiti)
At the Westinghouse Bridge on 26 March Dana Nesiti watched the male bring in food and stash it near the nest area. He may have heard the female call from the nest but can’t be sure because a noisy train went by right then.
Male peregrine at Westinghouse Bridge, 26 March 2022 (photo by Dana Nesiti)
62nd Street Bridge / Aspinwall Riverfront Park, Allegheny River:
Aspinwall RR Bridge, 12 Feb 2022 (photo by Kate St. John)
On 15 March Andrew Mumma saw gulls harass a peregrine falcon perched on the Aspinwall Railroad Bridge, shown above. Where did the peregrine come from? We don’t know but the 62nd Street Bridge is not far away.
62nd Street and Highland Park bridges as seen from underneath Aspinwall RR bridge (photo by Kate St. John)
Look for peregrines at the 62nd Street Bridge from either side of the river — on the Pittsburgh side or Etna Riverfront Trail. Tell me what you see. (Click the links to see maps.)
Tarentum Bridge, Allegheny River:
Female peregrine at Tarentum Bridge, 22 March 2022 (photo by Dave Brooke)
When Dave Brooke visits the Tarentum Bridge now he sees only one bird at a time, as on 22 March above. On 19 March his distant observation of the nestbox indicated that the female may have laid her first egg. The male was perched alone that day.
Male peregrine at the Tarentum Bridge, 19 March 2022 (photo by Dave Brooke)
The best place to watch this bridge is from the Armstrong Trail near or under the Graff Bridge. Park here on Water Street in Manordale (click link) and walk north (upstream) on the Armstrong Trail. Tell me what you see.
Speers Railroad Bridge, Washington County, Monongahela River: No news since February. Any news at all — seen or “didn’t see” — would be welcome! Click here for a map of the best vantage point.
Central stem of a white pine cone missing all its seed scales, bracts & seeds, Moraine State Park, 24 March 2022 (photo by Kate St. John)
27 March 2022
On a walk last week in Moraine State Park we found a pile of pine cones in various stages of undress. Some were uneaten, some were half eaten and many were stripped bare like the stem above.
White pine cones at the red squirrel’s midden: uneaten to completely gone
We can know this because of the focus on pine cones, how the cones were denuded, and the sizeable midden. Conifer seeds make up the majority of the red squirrel’s diet and he defends his midden territory year-round against every other red squirrel.
Red squirrels are highly territorial and asocial with very few non-reproductive physical interactions. The majority of physical interactions are in male-female matings and between females and their offspring before the offspring disperse to their own territories. The non-reproductive physical interactions recorded (0.6% of all recorded behaviors in one 19-year study) were all instances of chasing an intruder from a territory.
Flowering cherry in Pittsburgh, 24 March 2022 (photo by Kate St. John)
26 March 2022
This week the elms, maples, ornamental cherries and northern magnolias began to bloom in Pittsburgh. Their flowers have not yet reached their peak and that’s a good thing. Tomorrow night the low will be 19 degrees F and will devastate the tender petals.
Above, an ornamental cherry shows off its delicate pink-white blossoms in the sun on Thursday 24 March. Below, a northern magnolia flower peeks out of its winter coat in Schenley Park on Tuesday 22 March.
Northern magnolia flower bud, 22 March 2022 (photo by Kate St. John)
Red maple flowers, 22 March 2022 (photo by Kate St. John)
Cornelian cherry (Cornus mas), one of the earliest shrubs to bloom in western Pennsylvania, is a Eurasian member of the dogwood family. It can also look like an understory tree.
Cornelian cherry (Cornus mas) at Moraine State Park, 24 March 2022 (photo by Kate St. John)
Also blooming in yellow this week, forsythia is putting out tentative flowers.
Forsythia blooming (photo by Kate St. John)
And at Frick Park the hellebore planted near the Environmental Education Center is in full bloom (probably Hellebore odorus). I wonder if these nodding flowers will survive the cold.
Hellebore in bloom in Frick Park, 25 March 2022 (photo by Kate St. John)
Meanwhile I’m not worried about the new leaves on these hardy invasive plants. I doubt they’ll be damaged by the cold.
Bush honeysuckle leaf out in Frick Park, 21 March 2022 (photo by Kate St. John)Privet leaf out in Oakland, 23 March 2022 (photo by Kate St. John)Garlic mustard leaf out in Frick Park, 21 March 2022 (photo by Kate St. John)
Take a look at flowers today. They’ll be gone tomorrow night.
And finally there is the experiential illusion of a “gravity hill.”
A gravity hill, often referred to as a mystery hill, is a spot in the road where the layout of surrounding land and landmarks creates an optical illusion, making a slight downhill slope appear to be an uphill slope.
Skeptics have put the hills to the test, using magnetic detectors and levels. All indications suggest the hills are just illusions.
Because we humans can’t see ultraviolet light we miss the fact that some rocks glow in the dark after exposure to sunlight.
The glowing orange and green rock at top is a composite of willemite (normally brown glowing green) and calcite (normally white glowing orange). On display under normal light it is boring by comparison.
Other rocks can glow, too. Did you know that about 30% of diamonds glow under ultraviolet light? 99% of them glow blue but a few glow white, yellow, green, or red as shown below. See the explanation at Diamond Pro.
And here’s a rock called blueschist (benitoite-neptunite-joaquinite-natrolite) that is housed at the Carnegie Museum of Natural History. In black light it would stop me in my tracks.
Chickens were domesticated 5,000 years ago so this finding upends the notion that they came first.
Who was domesticated before chickens?
Before agriculture began 10,000 years ago, humans were nomadic in their search for food. The first two animals to be domesticated — dogs and sheep — were easily nomadic as well.
Agriculture prompted humans to form permanent settlements, which led to a spurt of animal domestication to keep the meat supply nearby. Here’s the list from dogs to chickens.
Intersex hen mallard, Duck Hollow, 20 March 2022 (photo by Michelle Kienholz)
22 March 2022
On Sunday at Duck Hollow we saw a female mallard with odd plumage. She was paired with a male mallard but she resembled a male in eclipse plumage. Was this duck a hybrid? Or was it something else?
Intersex hen mallard with her mate, Duck Hollow, 20 March 2022 (photo by Michelle Kienholz)
Michelle Kienholz was so intrigued that she took photos and sent them to the Duck ID group where she learned an amazing thing about female ducks. This odd mallard at Duck Hollow is an “intersex hen.” She is becoming male in a process called spontaneous sex reversal (SSR).
Female ducks are born with two ovaries but only one develops. The left ovary actively pumps out hormones to stifle the male genes, making the bird truly female. If a disease damages the only ovary and it stops producing hormones the female duck spontaneously turns into a male. Experiments have shown that the now-male duck is able to breed and fertilize eggs.
Because most ducks are sexually dimorphic a female with a dead ovary eventually looks male as well. The intersex hen at Duck Hollow is partway through her/his outward transformation, which is why she/he is in eclipse-like plumage.
Notice the clues in her/his feathers that indicate the transition:
tail feathers are black and curly white,
green feathers interspersed on head
breast is darkening (top photo)
color line between neck and breast is becoming white
Intersex hen: tail end is black with white feathers, green feathers on head (photo by Michelle Kienholz)Intersex hen, color line between neck and breast is becoming white (photo by Michele Kienholz)
For more information on bird sex chromosomes see Anatomy: W and Z. For photos of eclipse plumage see Mallards in Eclipse. And here is an article about spontaneous sex reversal in chickens, a problem for chicken farmers.
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