All posts by Kate St. John

East Liberty Peregrines’ Nest is Gone

12 April 2026

Adam Knoerzer monitoring every day. On 9 March he watched them fly around their territory and on 19 March he saw them bowing at the nest.

Peregrine flying around East Liberty Presbyterian steeple, 9 March 2026 (photo by Adam Knoerzer)

But on 2 April Adam wrote, “Dead quiet all week at East Liberty. Haven’t seen a single falcon the three times I’ve dropped by this week between 4-6pm.” It also looked like the sticks were gone.

Peregrine absence in those first days of April is not normal. In prior years the female laid eggs during that time. We wondered what was happening so Adam asked Ed Moore at East Liberty Presbyterian Church if he could check on the nest area.

On 8 April Ed sent the photo at right below and wrote, “Hi, Adam. Nothing up there. This pic is the ledge they were on last year. I checked all four corners and nothing.”

Two photos below show Before and After. At left is the nest with young in 2025. Notice the substrate that’s almost like mulch. At right is the same area now, circled in blue. It is completely empty.

East Liberty Presbyterian peregrine nest formerly on steeple: nest in May 2025, nothing in April 2026 (photos by Ed Moore)

What happened? My guess is the Wind!

The peregrines were using the remnants of a former red-tailed hawks’ nest which was built on the sloped steeple and held up by big sticks rimming the outside. The nest was located on the northeast corner which provided the best protection from Pittsburgh’s prevailing southwest winds as well as strong west winds.

In this Google satellite screenshot the steeple has a yellow arrow pointing to the nest location and green arrows for west winds. Unfortunately the nest was not protected from strong north winds, turquoise arrows below.

screenshot of showing East Liberty Presbyterian Church steeple. Markup shows nest location and winds (image from Google satellite map)

March was a stormy month with at least two storms that took down trees that blocked the roads. Statistics from one of those storms shows how bad the wind was.

On the night of 31 March a thunderstorm began with strong west winds at 43mph gusting to 58mph at 11:45pm. Five minutes later the wind had switched to the north gusting to 52 mph for another five minutes. The north wind is certainly a threat to the nest … if it was still there by that point.

screenshot of NWS detailed weather observations at Pittsburgh International Airport (KPIT) weather station, night of 31 March to 1 April 2026

Late in March or early April the East Liberty peregrines became homeless and had to find a new nest site because the female was ready to lay eggs. They could see a prime nest site not many miles away — the Cathedral of Learning — but it was already occupied. What to do? Harass the current residents to make them leave.

Apparently that harassment is in progress but it isn’t working yet. Over the past two weeks I’ve seen Carla and Ecco both step away from the eggs for a few moments to check the sky. Sometimes the parent on the eggs leaves the nest and the other one arrives. At one point when it was quite warm they were both gone for about an hour.

Carla checks the sky, 28 March 2026 (photo from the National Aviary snapshot camera at Univ of Pittsburgh)
Carla checks the sky, 31 March 2026
Carla checks the sky, 5 April March 2026

For Carla and Ecco retaining the nest site is more important than anything and they will put their all into it. Ideally the former East Liberty peregrines will find a nearby bridge to their liking.

Seen This Week: More Flowers and Leaves

Henbit blooming along Nine Mile Run Trail, Frick Park, 5 April 2026 (photo by Kate St. John)

11 April 2026

Despite temperatures that dipped into the upper 20s on Wednesday, spring is still making progress in Pittsburgh. This week I found more flowers and leaves.

Though they don’t look like flowers these yellow-orange structures are the inflorescence of bear corn (Conopholis americana, formerly squaw root), a underground non-photosynthesizing plant that is parasitic on beech and oak roots. The literature officially says “oak roots” but I always find bear corn under beech trees.

Bear corn in Schenley Park, 10 April 2026 (photo by Kate St. John)

The pawpaw trees (Asimina triloba) are blooming in Schenley Park. Their dark brown flowers have a faintly stinky smell to attract flies and beetles as pollinators. Pawpaw’s success is a good sign for zebra swallowtails (Eurytides marcellus). It is their only host plant.

Pawpaw flowers, Schenley Park, 10 April 2026 (photo by Kate St. John)

This week I finally noticed that the flowers on henbit (Lamium amplexicaule) and purple dead-nettle (Lamium purpureum) are nearly the same unusual shape — like the mouth of a tiny cave with a double landing pad at the opening. Duh! Of course they are similar. Both are in the Lamium genus, native to Eurasia.

In a patch of flowers along the Nine Mile Run Trail I found both plants in close proximity. The first photo has henbit in focus, the second focuses on purple dead-nettle so you can compare them.

Henbit (and purple dead-nettle) blooming along Nine Mile Run Trail, 5 April 2026 (photo by Kate St. John)
(Henbit and) Purple dead-nettle blooming along Nine Mile Run Trail, 5 April 2026 (photo by Kate St. John)

Jetbead (Rhodotypos scandens) has both flowers and leaves this week. Native to China and Japan it was planted in Schenley Park as an ornamental. Unfortunately it is invasive.

Jetbead in bloom, Schenley Park, 10 April 2026 (photo by Kate St. John)

Ohio buckeyes (Aesculus glabra) in Schenley Park have gone from merely leaves to blooming flowers in just one week. This tree had mild frost damage. If you look closely you’ll see a few dark green, shriveled leaves.

Ohio buckeye in bloom, Schenley Park, 8 April 2026 (photo by Kate St. John)

And yet, despite all the greenery the woods are still mostly bare. Sunlight reached the forest floor yesterday prompting woodland wildflowers to bloom.

Shadows and pale green leaves, Schenley Park, 10 April 2026 (photo by Kate St. John)

By 5 May all the trees will be leafed out and the spring wildflowers will have gone to seed.

Red-Tails Nesting in Schenley Park

Red-tailed hawks switch at the nest, Schenley Park, 3 April 2026 (screenshot from Dana Nesiti, Canonusr on Youtube)

10 April 2026

Last year in early April Dana Nesiti was filming great-horned owl siblings in Schenley Park but this year their nest is gone and the owls have relocated, we don’t know where. Instead Dana has found a red-tailed hawk nest where the pair is incubating eggs.

Red-tailed hawks are the most common hawk in southwestern Pennsylvania with at least three territories in Schenley Park, one of which is Dana’s favorite pair. On 3 April he visited them to see how their nesting is progressing.

video embedded from Dana Nesiti, Canonusr on Youtube

Last Friday was warm and very windy and it roared while Dana filmed the male on the nest.

The music he selected for Five Minutes in the Wind is calming and briefly dramatic. Enjoy.

video embedded from Dana Nesiti, Canonusr on Youtube

Urban Mallards Are Nesting Already

Female mallard (photo from Wikimedia Commons)

9 April 2026

In just three weeks there’s been a dramatic change in the number and mix of mallards seen at Duck Hollow.

In mid-March I reliably saw at least 20 from the parking lot and almost all were in pairs.

Mallard pair, female and male (photo from Wikimedia Commons)

At the end of March I watched a female checking out the thickets near this concrete path while her mate watched from the river’s edge. Their paired searching is typical of the female mallard’s nest site selection process so I paused to watch.

Duck Hollow, old boat launch at the Mon River, 28 March 2026 (photo by Kate St. John)

The female checked various bushes and walked up the bank (behind this view). Eventually she realized that too many people, including me, use the path so she rejected the spot and rejoined her mate in the river.

There’s a lot more to mallard nest site selection and building than we realize. This information paraphrased from Birds of the World is useful when you’re watching mallard behavior:

  • Mallards begin searching for a nest site within a few days of selecting their breeding home range (territory). The search is generally 5–10 days after the first “Persistent Quacking” by the female. (I’ve noticed that no one is quacking now!)
  • The female selects the nest site, usually on the ground in an upland area near water. For maximum concealment she places the nest under overhanging cover or in dense vegetation. In urban settings this might be underneath ornamental bushes, in woodpiles, in planters, hidden near docks, etc.
  • The pair does their best to make sure the area is safe from predators. “Experimental evidence suggests that mallards and several other dabbling ducks may be able to assess mammalian predator abundance and hence predation risk when selecting a nest-site by detecting (smelling!) these animals’ urine.”
  • The female makes the nest by forming a shallow depression or bowl on the ground in moist earth (‘digging the scrape’). She does not carry material to the nest but rather uses what she can reach and pull toward her with bill while sitting on nest.
  • During the laying phase, she improves the nest by lining the bowl with vegetation and plant litter from nearby. She also pulls and bends tall vegetation over to conceal herself and nest. After incubation begins, she plucks down from her breast to line the nest and cover the eggs when she takes a break from incubation.

This urban mallard chose a flower box for her nest and was probably surprised so suddenly that she didn’t cover her eggs.

Mallard nest in flower box. Notice the down feathers surrounding the eggs (photo from Wikimedia)

When I stopped by Duck Hollow on Tuesday 7 April there were only 6 mallards present. All but one of the ladies were missing. They are all on hidden nests.

Migration Looks Good Tonight, New Birds Tomorrow!

BirdCast’s Bird Migration Forecast for 8 April 2026 (accessed on 20260407 at 5:30am ET), birdcast.org, Univ. of Illinois, Purdue & Cornell Lab of Ornithology

8 April 2026

Tonight’s weather looks encouraging for bird migration over southwestern Pennsylvania. BirdCast’s forecast map shows them streaming from Texas to upstate New York along the Mississippi and Ohio Valleys. Oh boy! We’ll see new birds tomorrow.

The expected woodland migrants are the same species as last week, but with one addition. Fox sparrows and golden-crowned kinglets are on their last big push through the area, the warblers are here to breed, and the blue-headed vireo is not expected yet but has already arrived in Pittsburgh’s East End.

Other expected migrants include horned grebes and 7 duck species — lesser scaup, ring-necked duck, hooded merganser, red-breasted merganser, blue-winged teal and bufflehead. This year most of the ducks are passing through without stopping, so I felt lucky to see a pair of buffleheads at Duck Hollow yesterday.

Bufflehead pair (photo by Bobby Greene, photographed in 2011)

Check out Birdcast’s Migration Dashboard for Allegheny County for statistics and the ever-changing list of expected birds.

How Does a Snake Stand Up Like a Flagpole?

screenshot from embedded video of Snake Standing Up by IFLScience on YouTube

7 April 2026

Heads up: If you don’t like snakes you won’t want to look at this. 😮

Perhaps you’ve seen a garter snake stand up to look over the grass.

video embedded from WildUpmQua on YouTube

But this small feat is nothing to what this snake did at the zoo. Eventually it swayed too far to the left and … plop.

video embedded from Traveller Singh RS on YouTube

How do snakes do this?

To find out, scientists studied three brown tree snakes and a scrub python moving on a path with a vertical gap in the middle. At first the gap was 12 inches and each snake easily moved up to the higher level. For subsequent runs, the vertical gap was increased until the snakes had to stand straight up to reach the higher one 31 inches away.

The brown tree snakes could reach the upper perch even when the vertical distance exceeded 50 percent of their total body length. The scrub python’s climbing abilities were even more impressive, exceeding 70 percent of its total body length.

Smithsonian Magazine

Here’s one of the snakes running the course. Watch what he does.

video embedded from IFLScience on YouTube

After collecting the data …

The researchers used mathematical modeling to make sense of the snakes’ gravity-defying feats. The animals probably focus their muscle activity on a “boundary layer” at the base of their bodies near the lower perch, the team found. When the snake holds the part of its body above the “boundary layer” in an upright, nearly straight position, gravity has little leverage to pull the creature down.

“Curvature and muscular activity are large near the lower perch where the snake turns upwards, while in regions where the snake is vertical, no muscular forces are required since the gravitational torque vanishes there,” the researchers write in the paper.

Getting into the vertical pose doesn’t seem to require much energy. But holding the pose appears to be much more demanding, which is probably why snakes sway a bit when they’re upright.

Smithsonian Magazine

And that swaying is why the zoo snake fell down.

Read more in Smithsonian Magazine: How Do Snakes ‘Stand’ Upright Nearly Stick-Straight? New Research Points to How They Pull Off the Gravity-Defying Feat.

40 Years Later: Is Milk Still Radioactive?

Cows drink from drainage trench in Jelno, near Chernobyl, 2005 (photo from Wikimedia Commons)

6 April 2026

40 years ago today, on 6 April 1986, the Chernobyl nuclear power plant at Pripyat in the Soviet Union exploded in the worst nuclear disaster and the most expensive disaster of any kind in history.

At the time, Chernobyl was in the Soviet Union. Five years later, in December 1991, the Soviet Union dissolved and Ukraine and Belarus became independent. In 1996 the radiation exclusion zones spanned three countries: Ukraine, Belarus and Russia. Note how close the power plant was to the Belarus border.

1996 map of Radiation Exclusion and Control Zones due to Chernobyl disaster, CIA Handbook (from Wikimedia)

By 2016 it was safe enough to go on guided tours in the ghost town of Kopachi within the 10km Chernobyl exclusion zone. Here a tour guide shows his Geiger counter reading in Kopachi. (Don’t linger!)

Guide (Sergey) with Geiger Counter in Kopachi Village, Chernobyl Exclusion Zone, Ukraine, 2016 (photo from Wikimedia)

However two years later a 2018 study, published in the journal Environment International, found that cows as much as 140 miles away from the original disaster were still producing radioactive milk. The air was OK but a long-lived radioactive isotope in the soil, cesium-137, is easily taken up by the plants the cows consume and it gets into their milk.

According to the New York Times in 2018, the milk was five times the Ukrainian government’s official limit for adults, and more than 12 times the limit for children.

It is easy to see how this could happen. The cows pictured at top in 2005 were drinking water in a drainage ditch whose purpose was to gather water that cleansed radioactive isotopes from the contaminated soil. The photo caption reads:

Water drainage trenches like this one in Jelno – a village some 300 km away from the Chernobyl Nuclear Power Plant — removes excess water from the peaty soil as a first step. The next step is to diminish the content of radionuclides in the soil by ploughing and introducing mineral fertilizers. Caesium and potassium are chemical twins. Hungry for minerals, a plant will pull out caesium from the contaminated soil but if potassium is in good supply the plant prefers mineral fertilizer. (Jelno, Ukraine, July 2005)

photo caption, Wikimedia Commons

Here is a farm in 2011 within the 30km Chernobyl Exclusion Zone.

Cows on a farm in Pershe Travnia, Ukraine within the Cherbonyl Exclusion Zone, 2011 (photo from Wikimedia)

The 2018 study explained that the problem of radioactive milk could be fixed by adding hexacyanoferrate to cattle feed. This chemical binds with heavy metals, including cesium-137, but it is very expensive.

Unfortunately the problem is probably not being treated. Russia began their full out war on Ukraine on 24 February 2022(*) and there are more immediate dangers now than cancer. 40 years later the milk is probably radioactive.

For more about the Chernobyl disaster, see this documentary video from June 2019.

video embedded from OnDemand News on YouTube

Read more about the study in 2018 in the New York Times or in Newsweek.


(*) p.s. The war in Ukraine is Putin’s effort to regain what the Soviet Union lost due to a combination of factors that included the Chernobyl disaster:

The Soviet Union collapsed on December 25, 1991, due to a combination of chronic economic stagnation, unsustainable military spending, rising ethnic nationalism, and the unintended destabilizing effects of Mikhail Gorbachev’s reforms (glasnost and perestroika). These factors, exacerbated by the 1986 Chernobyl disaster and falling oil prices, led to a loss of central control and the eventual independence of its 15 republics. 

Google AI search result “why did the soviet union dissolve?”

An Easter Trout Lily

Trout lily at Fall Run Park, Glenshaw, 4 April 2026 (photo by Kate St. John)

Easter Day, 5 April 2026

This native lily is blooming today at Fall Run Park in Glenshaw, PA. I found it yesterday while looking for Louisiana warblers (Parkesia motacilla), whom we heard but never saw.

Trout lilies (Erythronium americanum) grow from 1/2″ to 1″ oval underground corms buried very deeply compared to other lily family plants. I believe the depth is an advantage for those that grow in a flood plain that washes away or fills with silt after a flood. For instance, at Raccoon Creek Wildflower Reserve.

When you find one trout lily you usually find many because they grow in colonies. Some trout lily colonies are as much as 300 years old. Individuals in a colony often reproduce asexually from small bulbs budding off of the main corm or via a tubular fleshy stem called a “dropper.”

The trout lily’s name comes from its “gray-green leaves, mottled with brown or gray, which allegedly resemble the coloring of brook trout.”

Brook trout caught and released (photo from Wikimedia) (*)

I used to think the flower partly got its name because it always blooms during trout season in Pennsylvania. (Trout season opened yesterday at 8:00am.)

Note: Most of this article is paraphrased from the Wikipedia article on trout lily.

Seen This Week: Greening Up

Virginia bluebells in Schenley Park, 3 April 2026 (photo by Kate St. John)

4 April 2026

Woodlots in the City are greening up with the first tentative leaves …

Schenley Park is greening up, 31 March 2026 (photo by Kate St. John)

… and full leaf on the Ohio buckeyes in Schenley Park.

Ohio buckeyes are the first to leaf out in Schenley Park, 3 April 2026 (photo by Kate St. John)

New flowers bloomed in the summer-like heat: Virginia bluebells near the Visitors Center and a star magnolia near the Westinghouse memorial.

The star magnolia’s flowers were in bud during the mid March freeze so it recovered well. Unfortunately, the forecast for Tuesday night, 7 April, calls for a low of 27°F. 🙁

Star magnolia at Schenley Park, 31 March 2026 (photo by Kate St. John)

Invasive garlic mustard leafed out on 15 March and was blooming this Friday.

Garlic mustard on 15 March and 3 April (photo by Kate St. John)

Coltsfoot went from flowers in snow on 19 March to full bloom on 3 April.

The photo below shows how many trees are greening up near the Panther Hollow Bridge which is covered in tarps for the current rehab.

What you can’t see is the female American robin carrying mud and grasses in her beak. She’s building a nest that she believes will be very safe, inside the tarp in the construction zone. The gap lets her in. Maybe the nest will be very safe. Maybe it’s a bad idea. She’ll find out.

Greening trees and a gap in the tarp at the Panther Hollow Bridge, 3 April 2026 (photo by Kate St. John)

And finally, more evidence of a bird that’s not in the photo. These track lines are small holes drilled by yellow-bellied sapsuckers. The tree heals the holes by growing more bark. Sapsuckers only visit Schenley Park on migration. I saw two yesterday.

Yellow-bellied sapsucker holes in a hickory, 31 March 2026 (photo by Kate St. John)

First 2026 Eaglet Hatches at Glen Hazel (Hays)

video embedded from PixCams on YouTube

3 April 2026

Yesterday morning, 2 April at 9:20am, the first egg hatched at the Glen Hazel (Hays) bald eagle nest. This video shows a closeup of the chick emerging from the egg. Notice the mother eagle’s talons and feet near the egg. She is so large and the chick is so small.

About 40 minutes later, the light rain had stopped and the sun came out. The mother eagle got up and we could see the chick dried off and moving. His mother made a soft chirping sound while a cardinal sang in the background.

video embedded from PixCams on YouTube

This is the first year there’s been a camera on the Glen Hazel nest though it’s their second nesting season at this site after they moved here from Hays.

Watch this growing family at PixCams: Glen Hazel (Hays) Bald Eagle Nest or follow PixCams on Facebook.

There’s a story in the Post-Gazette about Pittsburgh’s eagles (behind a paywall): It’s turning into a blockbuster season for Pittsburgh bald eagles – Post-Gazette, Mary Ann Thomas