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.
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.
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.
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.
Fox sparrow (photo by Charity Kheshgi)
Golden-crowned kinglet (photo by Steve Gosser)
Louisiana warbler (photo by Steve Gosser)
Yellow-throated warbler (photo by Steve Gosser)
Blue-headed vireo (photo from Wikimedia)
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)
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.
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.
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.
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!)
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)
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.
(*) 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.
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.”
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 yellow buckeyes in Schenley Park.
Yellow 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.
Coltsfoot in snow, 19 Mar 2026
Coltsfoot bud and flower, 3 April 2026
Coltsfoot blooming, Schenley, 3 April 2026
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)
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.
Louisiana waterthrush, early April 2020 (photo by Steve Gosser)
2 April 2026
Now that it’s early April a whole new set of birds is expected to arrive on migration. Here are three woodland birds to look for this coming week.
Louisiana waterthrushes (Parkesia motacilla), pictured at top, first arrived in southwestern Pennsylvania on Monday 30 March, basically right on time. They were reported in at least seven locations 30-31 March but eBird considers them “rare” until 1 April so all of those March sightings generated Rare Bird Alerts.
Watch for a sparrow-sized bird with bubblegum pink legs that walks along the edges of babbling creeks. While it walks it keeps its tail cocked up and bobs the back end of its body as well as its tail. Listen for its song; click here to watch it singing.
Yellow-throated warblers (Setophaga dominica) aren’t here yet but it’s only a matter of days. They were reported in Bridgeport and Elkins, West Virginia on 30-31 March. Look for them high in sycamore trees along creeks and rivers. Unlike most warblers this one stays high in the trees and walks the largest branches. It is relatively slow moving compared to an American redstart, but then redstarts are almost frantic.
Yellow-throated warbler, May 2022 (photo by Steve Gosser)
Not really new but easier to find this week, a handful of golden-crowned kinglets (Regulus satrapa) have been in southwestern Pennsylvania all winter but the first big push of migrants arrived in the third week of March, around the time of the Spring Equinox. This week the Merlin app hears a golden-crowned kinglet whenever I’m out birding (I can’t hear them.)
On April Fool’s Day 2008 the BBC published a tongue-in-cheek video about the “discovery” of a flock of flying penguins who migrate to the rainforests of South America.
Notice how the background documentary-type music sucks you in to make it more believable. This has gotta be real, right? The music says it is. 😉
Simultaneously the BBC also published The Making of Penguins April Fool that shows how the spoof was made using top notch production techniques and the latest special effects of 2008. They recorded the narrator on green screen, created physical models of penguins in flight, and used animation to bring them to life on the screen.
To our 2026 eyes it all looks so old. It was only 18 years ago but for this type of video it is ancient history. Nowadays it would be generated by AI.
Bird Bonus Fact:
In the “Making of” video they say they modeled the fictitious flying penguins on a similar bird that actually does fly. The common murre (Uria aalge), called a common guillemot in Eurasia, lives on northern oceans in the sub-Arctic and low-Arctic zones. I have seen them nesting in Newfoundland. Their body shape and lifestyle make them the Penguin of the North.
Here’s a short flight video with a tufted puffin in the mix.
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