Yesterday Before the Rain at Duck Hollow

Books & Events, Songbirds
Nodding thistle was the only spot of color on a drab day, Duck Hollow, 1 July 2023 (photo by Kate St. John)

3 July 2023

I’ve had to cancel so many bird walks this spring that I decided to hold yesterday’s 8:30am outing at Duck Hollow despite the fact that it was certain to pour within 45 minutes.

The sky was gloomy gray, the river was like glass and the fish were jumping. The only spot of color was nodding thistle (Carduus nutans), a biennial from Eurasia.

Rain is coming at Duck Hollow, 2 July 2023, 8:44am (photo by Kate St. John)

Just two of us were hardy enough (crazy enough?) to show up. It started raining steadily in only 40 minutes. We called it quits and went home.

But the birds were quite good considering the weather. Favorites were …

  • A family of belted kingfishers with two begging youngsters. One of the “kids” held his wings wide open to attract attention, like the begging move of a fledgling peregrine.
  • Two warbler species: a yellow warbler and a very wet black-and-white warbler that walked the branches of a black locust.
  • A recently fledged northern mockingbird in a mulberry tree with ripe fruit, along with house finch families with begging young.

Our checklist is here https://ebird.org/checklist/S143326273 and listed below.

Duck Hollow, Allegheny, Pennsylvania, US
Jul 2, 2023 8:30 AM – 9:10 AM
— 18 species —
Canada Goose (Branta canadensis) 10
Mallard (Anas platyrhynchos) 12
Chimney Swift (Chaetura pelagica) 10
Herring Gull (Larus argentatus) 5
Belted Kingfisher (Megaceryle alcyon) 4, Two begging youngsters
Red-bellied Woodpecker (Melanerpes carolinus) 1
Blue Jay (Cyanocitta cristata) 1
Northern Rough-winged Swallow (Stelgidopteryx serripennis) 6
Carolina Wren (Thryothorus ludovicianus) 4
Northern Mockingbird (Mimus polyglottos) 1 Recently fledged with rumpled gape.
American Robin (Turdus migratorius) 5
House Finch (Haemorhous mexicanus) 12, feeding young
Song Sparrow (Melospiza melodia) 3
Red-winged Blackbird (Agelaius phoeniceus) 7
Common Grackle (Quiscalus quiscula) 3
Black-and-white Warbler (Mniotilta varia) 1
Yellow Warbler (Setophaga petechia) 1
Northern Cardinal (Cardinalis cardinalis) 5

(photos by Kate St. John)

Panther Hollow Lake Refills

Schenley Park
Panther Hollow Lake, Schenley Park, 1 July 2023 (photo by Kate St. John)

2 July 2023

Yesterday I was curious about the status of Panther Hollow Lake after I’d found it more than half drained out on Friday 23 June. I was out of town last week so yesterday was my first opportunity to see what happened. Happily, Pittsburgh’s Department of Public Works and PWSA fixed the leak while I was away. The lake is refilling slowly as it rains.

These before and after slides show the same views on 23 June and 1 July.

Formerly a sea of mud, it now has water.

  • Panther Hollow Lake is empty here, 23 June 2023 (photo by Kate St. John)
  • Panther Hollow Lake, cone in the mud, 23 June 2023

Here’s the drain on 23 June with mud at the outflow and water on 1 July.

  • Panther Hollow Lake going down the drain, 23 June 2023

(photos by Kate St. John)

Pittsburgh’s Most Common Hawk

Birds of Prey
Red-tailed hawk in North Park, Feb 2019 (photo by Steve Gosser)

1 July 2023

Last week while in Tidewater Virginia, I noticed that turkey vultures dominated the airspace. On our way to Pittsburgh yesterday, soaring red-tailed hawks made me feel like “I’m home.”

Red-tailed hawks (Buteo jamaicensis) live quite near us in southwestern Pennsylvania, especially in the city. Here are a few shots of our most common hawk, thanks to local photographers.

Red-tailed hawk in flight, January 2022 (photo by Christopher T)
Red-tailed hawk nestling, Frick Park, May 2021 (photo by Charity Kheshgi)
Red-tailed hawk family in a nest in Schenley Park, 14 May 2018 (photo by Gregory M. Diskin)
Red-tailed hawk family in a nest in Schenley Park, 14 May 2018 (photo by Gregory Diskin)
Immature red-tailed hawk on light pole, 2013 (photo by Chuck Tague)
Pair of red-tailed hawks on Hammerschlag Hall at CMU, April 2011 (photo by Peter Bell)
Immature red-tailed hawk at Pitt Law School window, fall 2019 (photo by Kim Getz)

(photo credits in the captions, click on the links to see the photographers’ websites)

Bird on a Groundhog?

Mammals, Travel
Cattle tyrant bird on a capybara (photo from Wikimedia Commons)

30 June 2023

You’ll never see this bird and mammal wandering in North America.

The bird is the cattle tyrant (Machetornis rixosa) of South America, related to the great kiskadee whose northern range extends into south Texas.

The mammal is the world’s largest rodent, a capybara (Hydrochoerus hydrochaeris), also in South America.

Capybaras are semi-aquatic (“hydro” in their genus name) and very social, living in groups of up to 100 individuals. See both characteristics in this video.

Capybara’s are so large that a raptor can look small when perched on one of them as shown in this vintage article.

Caracara, Capybara

Bees’ Hair Stands on End

Insects, Plants & Fungi
Honeybee collecting pollen (a featured picture from Wikimedia Commons)

29 June 2023

When bees visit flowers they collect two kinds of food: nectar for energy and pollen for protein and nutrients. The pollen is food for their larvae in the hive so they carry it home in the pollen sacks on their legs.

Honeybee with full pollen sack (photo from Wikimedia Commons)

Filling the pollen sacks requires static electricity, grooming and a bit of nectar to make the pollen clump.

When a bee lands on a flower, the hairs all over the bees’ body attract pollen grains through electrostatic forces. Stiff hairs on their legs enable them to groom the pollen into specialized brushes or pockets on their legs or body, and then carry it back to their nest. 

— Michigan State University, MSU Extension: Pollination

Because bee’s hairs are oppositely charged from the flowers, their the hairs stand on end as they approach them …

Common eastern bumblebee, Wisconsin (photo from Wikimedia Commons)

… and this makes it easier to find the flowers in flight. Learn more in this 2016 article:

Bees and Electricity

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

Long Term Success of Dune Grass Fails in Major Storms

Water and Shore
Dune grass at Delaware Bay (photo from Wikimedia Commons)

28 June 2023

It’s time for summer vacation when we climb over grassy dunes to get to the beach.

Steps over the dune (photo from Wikimedia Commons)

Beach grass planted on our sandy coasts stabilizes dunes and protects against storms. As the grass expands it holds down larger areas and provides more protection, but a new study published this month in Science Advances found that dune grass fails in major storms.

The same scientists that taught us the value of dune grass realized they’d never tested it for major storms. Rusty Feagin, a coastal ecologist at Texas A&M University, decided to simulate the effects of Hurricane Sandy (October 2012) so he teamed up with Oregon State University where they house the largest wave tank complex in the U.S. It’s longer than a football field (104 m).

The team set up two dunes, one planted in dune grass whose roots spent six months taking hold, the other a bare dune. “VD” = vegetated dune, “BD” = bare dune

Dunes built for simulated extreme storm event (from Science Advances: Does vegetation accelerate coastal dune erosion during extreme events?)

Then they pounded the dunes with a Hurricane Sandy simulation — 19 hours of punishing waves — stopping every half-hour to laser-scan the dunes.

On the bare dune the waves rolled straight up slope (“BD runup”) and removed sand but left the slope basically the same. On the vegetated dune the waves undercut the grass and caused a cliff, making the dune more vulnerable in future storms. (“VD runup” and yellow circle)

Here’s what the vegetated dune looked like near the end of the storm (from above and the cliff face).

Here’s a real life example of major storm damage to a grassy dune.

Cliff-like erosion at the edge of dune grass (photo from Wikimedia Commons)

Feagin says we should still use dune grass, but change our expectations. Science Magazine explains:

Even if the plants cause dunes to erode in severe conditions, Feagin says, it’s still worth having them for protection from milder storms. “When that medium-small storm hits, [the dune] is going to do its job, but the giant [storm] every 10 years is gonna take it out.” And vegetated dunes have advantages over concrete walls for storm protection, because native plants can grow and spread. That means the plants can help dunes increase in size as they trap sand, and perhaps keep up with rising sea levels.

The take-home point of paper is “more about managing expectations” of vegetated dunes, Feagin says. They are not a panacea for coastal protection, he suggests — and land managers shouldn’t expect them to deliver permanent stability.

Read more about the dune grass experiment in Science Magazine: In a twist, beach grass could make dunes more vulnerable to storms. See the study itself in Science Advances.

(photos from Wikimedia Commons and Science Advances: Does vegetation accelerate coastal dune erosion during extreme events?, Creative Commons license)

Panther Hollow Lake Found Empty Last Friday

Schenley Park
Panther Hollow Lake bottom exposed, 23 June 2023, 8:38am (photo by Kate St. John)

27 June 2023

On my Friday morning walk in Schenley Park (23 June 2023) the first thing I noticed from the Upper Trail was that Panther Hollow Lake looked really odd. When I got down to the edge I found out why. The lake had drained out, leaving half of it a sea of mud.

Panther Hollow Lake was built in 1892 by damming Panther Hollow Run and directing its outflow to a sewer pipe containing its original drainage, Four Mile Run, plus sewage. Last week something went wrong at the outflow point and the lake emptied.

Panther Hollow Lake, drained out at this outflow point, 23 June 2023, 8:56am (photo by Kate St. John)

Within 15 minutes of my Friday call to Pittsburgh 311, employees from two City Departments arrived on the scene. By mid-morning the Department of Public Works and Pittsburgh Water and Sewer Authority were working to fix the outflow.

DPW at Panther Hollow Lake outflow awaiting PWSA, 23 June 2023, 10:15am (photo by Kate St. John)

Today (27 June) Panther Hollow Lake is probably filling again but I’m out of town and haven’t had a chance to see it. If you visit the lake this week, leave a comment to let me know how it looks.

Meanwhile, this episode does not fix Panther Hollow Lake’s underlying problems of summer algae blooms and its unnatural concrete edge that prohibits lakeside vegetation. The algae blooms in part because the lake is shallow. The lake is shallow because it’s passing through the normal life cycle of a lake, illustrated in this diagram from NHLakes: The Life of a Lake.

diagram from The Life of a Lake at NHLakes.org

Once formed, lakes do not stay the same. Like people, they go through different life stages—youth, maturity, old age, and death. All lakes, even the largest, slowly disappear as their basins fill with sediment and plant material. The natural aging of a lake happens very slowly, over the course of hundreds and even thousands of years. But with human influence, it can take only decades.

… Eventually, the lake becomes a marsh, bog, or swamp. At this point, the drying-up process slows down dramatically; limnologists aren’t sure why. Eventually, the lake becomes dry land.

— The Life Cycle of Lakes, National Geographic

At this point eutrophic Panther Hollow Lake is “old” and somewhat like a marsh, a state that can last a long time without much change. But the lake’s 130 year history is filled with human intervention, from construction in 1892, through two “renovations” (1909 and 1957), and plans made in 2010-2016 to renovate again. Those plans fell through last November and put Panther Hollow Lake on hold.

Last Friday’s drain-out will likely restart the planning process. Meanwhile, the marsh attracted two rare birds in late April (American bittern and sora) and still has nesting red-winged blackbirds. On Friday the remaining “puddle” at the deep end held two Canada geese and a great blue heron, both unbothered by low water.

Two Canada geese and a great blue heron are not bothered by low water, 23 June 2023 (photo by Kate St. John)

Curious about the life stages of a lake? See:

(photos by Kate St. John, diagram courtesy nhlakes.org)

Duck Hollow Outing, Sun July 2

Books & Events
Spotted knapweed with a metallic green bug, early July 2013 (photo by Kate St. John)

26 June 2023

Join me this coming Sunday for a bird and nature walk at:

Duck Hollow and the Lower Nine Mile Run Trail — 2 July 2023, 8:30am to 10:30am.

Meet at Duck Hollow parking lot at the end of Old Browns Hill Road.

We’ll see flightless Canada geese, swallows over the river, busy birds with young, midsummer flowers, and insects like this metallic-green bug on spotted knapweed. I’m hoping for an indigo bunting.

Dress for the weather and wear comfortable walking shoes. Bring binoculars, field guides and a scope for river watching if you have them. Don’t forget to bring water, sunscreen and a hat.

As of this moment, Scattered Thunderstorms are predicted for 2 July but we all know that could change for the better or worse so check the Events page before you come in case this outing is canceled for thunder or heavy downpours.

Hope to see you there.

p.s. This July has five Sundays so the next outing will be on Sunday 30 July.

(photo by Kate St. John)

Listen For Merlins Nesting Near You

Birds of Prey, Nesting & Courtship
Merlin family at Chatham University, Pittsburgh, PA, July 2022 (photo by Malcolm Kurtz)

25 June 2023

Last year Malcolm Kurtz found the first recorded merlin nest in Allegheny County when he heard them on Chatham University’s campus. They were easy to find because merlins are extremely vocal during the breeding season, especially late June through July when their young beg loudly. If you recognize the sound you may discover merlins nesting near you. In Pennsylvania this is a very big deal and Don Nixon, who tracks Pennsylvania’s merlins, wants to know about it.

Merlins (Falco columbarius) are small, streaky, dark, very fast falcons about the size of pigeons who, after the DDT crash, did not nest in Pennsylvania for over 30 years. When they returned they chose old unmodified crow or hawk nests in conifers in forests, cities, residential areas, school yards, parks, cemeteries, and golf courses.

Don Nixon has seen merlin numbers grow quickly in recent years and writes:

  • We now have over 100 documented merlin nests across Pennsylvania since 2006.
  • Nest sites stretch from a repeatedly used area at Promised Land State Park in the Poconos to a golf course in Somerset.
  • Nests have been reported in 24 of Pennsylvania’s 67 counties.
  • Counties reporting nests for the first time in 2022 include Allegheny (Malcom’s nest), Blair, Cameron, Clarion, Columbiana and Somerset. 
  • This year Lackawanna County is already reporting its first nest.

Don publishes an annual PA merlin map after the breeding season, 2022 shown below. The dots appear clustered because there are few observers.

Pennsylvania merlin nests in 2022 (map from Don Nixon)

Since merlins don’t use the same nest site in consecutive years these dots don’t tell you where to find merlins this year. Instead you’ll have to listen for them. The two most common calls, described by Birds of the World, are:

  • Ki-Ki-Kee (Kek-Kek-Kek) given in courtship displays, territorial or other aggressive encounters,
  • Food Begging Whine: a monotonous call, given by female soliciting food transfers from male. Sometimes given after copulation. Also given by nestlings but softer and quicker.

Here are three examples:

Alarm near the nest, Xeno Canto 666137:

Female calling after mating with male, Xeno Canto 642023:

Adults and begging juvenile, Xeno Canto 583041:

If you hear these sounds look for merlins. If you heard them in Pennsylvania, Don Nixon wants to hear from you. Add your own dot to the PA Merlin Map. Contact Don at:

Don Nixon
1009 Green Glen Drive, DuBois, PA  15801
814-661-5944 (cell)
pamerlins@gmail.com

Now’s the time to listen for merlins. Maybe you’ll find a nest!

(photo by Malcolm Kurtz, map from Don Nixon)

Two Kinds of Mullein

Phenology, Plants & Fungi
Common mullein in bloom, Aspinwall, 21 July 2021 (photo by Kate St. John)

24 June 2023

Two kinds of mullein are blooming now in western Pennsylvania. Both are native to Eurasia and northern Africa and are listed as invasive in some states, but not in Pennsylvania.

Common mullein (Verbascum thapsus) is hard to miss in late June, standing 5-6 feet tall with a spike of yellow flowers. This hairy biennial plant spends its first year as a rosette of fuzzy basal leaves, similar to the early stage of lamb’s-ear.

Basal rosette of common mullein leaves, April 2016 (photo by Kate St. John)

In the second year it sends up a tall shoot topped by a flower spike.

Common mullein, Ohio River Trail, Pittsburgh, 18 June 2023 (photo by Kate St. John)

As the spikes go to seed in late July you can see why people used these plants as torches.

Common mullein by the river, Pittsburgh, 23 July 2017 (photo by Kate St. John)

Moth mullein (Verbascum blattaria), like common mullein, is also biennial but its flowers are prettier and more delicate.

Moth mullein in bloom, 25 July 2015 (photo by Kate St. John)

The basal leaves are hardly noticeable because the flowers draw so much attention.

Moth mullein basal leaves (photo by Bruce Ackley, Ohio State University via Bugwood.org)

The plant blooms from the bottom up …

Moth mullein, 12 June 2021 (photo by Kate St. John)

… and goes to seed in the same direction. Each seed pod looks like a ball with a string on top.

Moth mullein seed pod, 14 July 2019 (photo by Kate St. John)

Other than its beauty, moth mullein has an unexpected benefit. According to Wikipedia, it has “long been known to be an effective cockroach repellent, and it’s species name blattaria is actually derived from the Latin word for cockroach, blatta.”

Torches and cockroach repellent. Something to think of when you see these two mulleins.

(photo credits are in the captions)