All posts by Kate St. John

Stinkbug Predator Travels to Find Prey

October 16, 2025Insects, SpidersKate St. John

Samurai wasp ovipositing on brown marmorated stink bug eggs (photo from Wikimedia Commons)

16 October 2025

Remember the brown marmorated stink bug invasion? Halyomorpha halys was first noticed in Allentown PA in 1998 and soon spread across the state. By 2010 alien stink bugs were causing record damage in Pennsylvania orchards and annoying homeowners by invading tiny cracks in our homes at the first sign of cold weather. October used to be the worst month for this.

Brown marmorated stink bug outside my window, August 2023 (photo by Kate St. John)

Studies back then predicted where the stink bug was likely to invade while USDA searched for a biological control. They were looking for a predator within the brown marmorated stink bug’s native range that would not pose a threat to North American species.

Meanwhile the stink bug continued to spread. Within 20 years it was thick in the I-95 Corridor, clearly established east of the Mississippi, and had spread in the Pacific coast states.

Distribution of brown marmorated stink bug in the U.S. 2000 to 2019 (animation from Wikimedia Commons)

By 2018 researchers had settled on a safe non-stinging wasp, the Samurai wasp (Trissolcus japonicus), that lays its eggs inside brown marmorated stink bug eggs; its larva eats the egg from within. The map below shows the wasp’s potential range around the world. Its outlook as a solution in the eastern U.S. was great but it was marginal to unsuitable in the West.

Approvals to import the wasp were still grinding through the bureaucratic process when the Samurai wasp showed up on its own as described in this vintage article: Stinkbug Predator Shows Up On Its Own.

As soon as that happened the wasp became available to farmers in need of stink bug control and the wasp continued to spread naturally.

By 2021 it had spread to North Carolina and surprisingly to southwestern Idaho, a place that was mapped (above) as marginal-to-unsuitable habitat for the wasp.

But the wasp doesn’t care. There are stink bugs in Idaho so the wasp flew east out of Oregon and found a new home. This USDA map on the stopbmsb.org website shows the distribution of both species, the stink bug in solid colors, the wasp as dots.

USDA map of brown marmorated stink bug and Samurai wasp distribution via stopbmsb.org

Back here in Pennsylvania I rarely see brown marmorated stink bugs anymore, thanks to the female Samurai wasp who’s a great traveler in search of stink bug eggs.

p.s. I wonder how she finds the stink bugs. Can she smell them from afar?

UPDATE: See the comments! Some people still have stink bugs at home

Where Does the Plume Go?

October 15, 2025Musings & News, Weather & SkyKate St. John

Quenching and smoke at Clairton Coke Works during inversion, 15 May 2021 (photo by Mark Dixon BlueLens via Flickr Creative Commons license)

15 October 2025. More on the subject of wind.

Though Pittsburgh’s air has improved since the Smoky City days, we still have heavy industry and unhealthy air too frequently. The rotten egg smell of sulfur lingers when there’s a temperature inversion, and since Pittsburgh averages 157 inversion days per year it’s likely there’s bad air somewhere here almost half the time. But not everyone smells it. It depends on where the plume goes, and that depends on the surface wind or lack thereof.

After CMU’s CREATE Lab published the SmellPGH app in 2016 for crowd-sourced bad air reports, they went on to develop the PlumePGH website in 2021 that shows where the bad air goes. I learned about PlumePGH in a Public Source article last week.

This two minute video explains how it works showing air movements on 10 December 2020. Back then the Cheswick power plant (orange plume) was still in operation; it closed on 31 March 2022.

video embedded from CREATE Lab on YouTube

To whet your appetite for the PlumePGH website, here are still shots from a recent bad air day on Saturday 4 October 2025. A screenshot of the SmellPGH map on 4 October shows that the air was really awful and a lot of people noticed it.

screenshot from SmellPGH app for 4 October 2025

Selected screenshots from PlumePGH on the same day shows 3 plumes. U.S. Steel’s …

Clairton Coke Works (Clairton PA) in purple
Irvin Works (West Mifflin PA) in yellow
Edgar Thomson Works (Braddock PA) in blue-green.

At 3:48am the wind was from the south. All 3 plumes intermingled as they headed north.

screenshot from Plume PGH timelapse video of 2025-10-04

Around noon the wind died and a lot of people were unhappy in the river valleys.

At 5:35pm the wind picked up out of the southeast and a whole new set of folks smelled rotten eggs.

Click this link to see the whole Plume PGH timelapse video for 2025-10-04.

Visit the PlumePGH website for more information.

Wing Transplant Saves A Butterfly’s Life

October 14, 2025Insects, Spiders, MigrationKate St. John

Monarch butterfly in flight (photo from Wikimedia Commons)

14 October 2025

In Case You Missed It

Two weeks ago a monarch butterfly with a broken wing was brought to Sweetbriar Nature Center on Long Island where they have a butterfly house (vivarium) with a wide variety of species. The injured monarch could not fly and would surely die but the Nature Center’s Wildlife Rehabilitation Director, Janine Bendicksen, searched for a dead monarch butterfly in the vivarium and performed a wing transplant.

video embedded from CBS New York on YouTube

The patient is a member of the migratory brood who travel to Mexico to spend the winter. Without the transplant she could never resume her journey.

Monarch Butterfly Fall Migration Patterns from US Forest Service

Flying solo, she is now traveling 50-100 miles a day and resting at night at communal roosts.

Journey North tracks monarch butterfly fall roosts on their website. Click here or on the screenshot below to see the map and play the animation as the roosts change through time.

SCREENSHOT 14 Oct 2025: Journey North map of Monarch Fall Roosts

NOTE: The absence of roosting spots in the eastern U.S. does not necessarily mean they don’t exist. It may mean these roosts are not as noticeable in the forest compared to the Plains or that no one is reporting on them.

3,000 Crows Outside My Window

October 13, 2025Crows & RavensKate St. John

Crows heading for the roost at dusk in Pittsburgh (photo by Kate St. John)

13 October 2025

My sixth floor windows are a good place to watch birds in flight. Last month I saw chimney swifts diving into Cathedral Mansions chimney (see chimney swifts video in 2020). This month Pittsburgh’s growing winter crow flock flies past my window on their way to the roost.

They’re Back!!!!

On Saturday 10 October I counted 3,000 crows but was too busy counting to take pictures.

Last night I captured lots of video which I stitched together for a minute+ of crows in flight. Crow fans will watch the whole thing but most of you will want to ditch out early without watching every single crow.

12-Oct-2025 video by Kate St. John

Several times in the video: Wondering why a single crow wheels, turns, and heads backward and down? He’s seen his buddies on the roof next door and wants to join them.

For now the crows are roosting somewhere near Pitt but as their numbers grow to 10,000 or 20,000 they’ll wear out their welcome and be urged to “move along” and change the roost. When that happens they won’t fly past my building anymore. The last few days have been a rare opportunity to count crows outside my window.

Distant Noreaster Shuts Down Migration in Pittsburgh

October 12, 2025MigrationKate St. John

screenshot of BirdCast, live migration map, 2025-10-12, 5:30am EDT, Cornell Lab of Ornithology Mark-up shows no migration occurring in Pennsylvania.

12 October 2025

Yesterday morning BirdCast predicted high migration for our area but a distant nor’easter got in the way. By the end of the day Birdcast had changed its prediction but I didn’t see it until this morning and was quite surprised. What happened?

A nor’easter has been churning off of North Carolina’s Outer Banks bringing high surf, wind and heavy rain to southeastern Virginia and eastern North Carolina. As the sun set last night the storm was hitting those areas but its core was not tight yet (see 5:30pm green map below). At this point BirdCast had already changed their prediction.

Winds at 4,900 ft, 2025-10-11, 5:30pm from earth.nulshool.net. Pink is approx location of PA

By 9:30pm last night, birds were leaving our area but none were flying in. The rest of the state and most of the East Coast were a no-fly zone.

screenshot of BirdCast, live migration map, 2025-10-11, 9:30pm EDT, Cornell Lab of Ornithology

By this morning the nor’easter had tightened its core, the winds were much stronger and it was forcing east wind across Pennsylvania all the way to Pittsburgh. This wind map shows the air below 5000 feet — the region where most migratory birds fly overland.

Winds at 4,900 ft, 2025-10-12, 5:40am from earth.nulshool.net. Pink is approx location of PA

You can see how it shut down migration over Pittsburgh in this BirdCast screenshot from 12 October at 5:30am EDT. The no-fly zone is now from Pennsylvania through South Carolina.

screenshot of BirdCast, live migration map, 2025-10-12, 5:30am EDT, Cornell Lab of Ornithology

And the storm has certainly heated up. Here’s the latest from the OuterBanks via WRAL TV in Raleigh, NC.

video embedded from WRAL on YouTube

No wonder the birds stayed put!

Seen This Week: Glasswort, Cormorants and a Puffball

October 11, 2025Plants & Fungi, Schenley Park, Travel, Water and ShoreKate St. John

Cape Cod view at the end of Navigation Road, Banstable, MA, 4 October 2025 (photo by Kate St. John)

11 October 2025

A week ago at Cape Cod I was birding with Bob Kroeger along Navigation Road in Barnstable when we popped out at this beautiful salt marsh scene at the end of the road.

I took the red foliage for granted until I got close. Glasswort’s succulent leaves provide the clue that it thrives in saline habitats. In spring and summer this plant is green so I probably didn’t notice it. In October it turns a beautiful red. I think this is Virginia glasswort (Salicornia virginica).

Virginia glasswort, Navigation Road, Cape Cod, 4 October 2025 (photo by Kate St. John)

Succulent leaves of Virginia glasswort, Cape Cod, 4 October 2025 (photo by Kate St. John)

I’d been telling my sister-in-law about the crows that roost in Pittsburgh in the winter and she said, “You ought to see our cormorants.” As sunset approached we followed the bike trial to the Bass River in South Dennis and found 300 double-crested cormorants with more coming in all the time. I’ve heard that people aren’t happy that the birds roost on the wires over the river, but this is certainly a case of build-it-and-they-will-come.

Cormorants coming in to roost at the Bass Rover, South Dennis, MA, 4 Oct 2025 (photo by Kate St. John)

Back home in Pittsburgh, 10 October: While walking in Schenley Park yesterday I saw something white in a splash of sunlight in the woods. Was it trash?

What’s that white thing in the woods? Schenley Park, 10 Oct 2025 (photo by Kate St. John)

When I bushwhacked to examine it I found a large puffball mushroom with a corner broken off. The last time I saw one in Schenley Park was 10 years ago!

Puffball mushroom, Schenley Park, 10 Oct 2025 (photo by Kate St. John)

I can’t tell you what species this is but there are many examples in this Wikipedia article on puffballs.

Blue Jays Are Busy Planting Trees

October 10, 2025Bird Behavior, Crows & RavensKate St. John

Blue jay carrying acorns, September 2022 (photo by Christopher T)

10 Oct 2025

October is nut season and the blue jays are busy. We see them flying back and forth on the same route all day long on. What are they doing?

At this time of year blue jays eat acorns from the treetops and carry many more in their gular sacks and beaks to cache at home for the winter. They always go overboard and cache more than they’ll ever eat. So, unintentionally, blue jays are planting trees.

Blue jay parents and grown kids all contribute to storing food in their home territory. Here are some cool facts about how and why they do this. (information is from Birds of the World)

Blue jays are omnivores but during oak mast season their diet becomes 67% acorns.
They prefer pin oak (Quercus palustrus) and willow oak (Quercus phellos) acorns, not red oak (Quercus rubra) or white oak (Quercus alba). –> That’s why I see them flying to a courtyard that has pin oaks.
They also prefer to gather acorns on the tree, versus on the ground.
Each time they fly home they usually carry 1-5 acorns or up to 15 beechnuts, depending on size.
To carry the nuts, they store 2-3 in their distended throat and anterior esophagus + one in mouth + one at bill-tip. The blue jay pictured above has a bulging throat but the acorn in his mouth is too large for him to carry one in his bill-tip.
“Each individual adult probably harvests and eats or caches several thousand acorns, beechnuts, hazelnuts, hickory nuts, or other hard mast each autumn.
This tendency may account for the rapid postglacial dispersal of oaks.” — Birds of the World

The 9-minute video below shows blue jay caching behavior and explains how blue jays probably plant more trees than squirrels!

video embedded from MyBackyard Birding on YouTube

Click here to watch the video on YouTube and see the links to the author’s source material.

Water is Dropping at Lake Erie

October 9, 2025Water and ShoreKate St. John

Lake Erie at Presque Isle State Park, Dec 2016 (photo from Wikimedia Commons)

9 October 2025

On Tuesday meteorologist Ross Ellet posted on Facebook that the water level in Lake Erie will drop 5 inches in the next month according to the U.S Army Corps of Engineers. Click on this embedded image to see his message on Facebook.

Lake Erie image embedded from Meteorologist Ross Ellet on Facebook

In case you’re not on Facebook, Ross Ellet went on to explain:

A 5″ drop on Lake Erie over a month is impressive and would equal about 850 billion gallons of water lost. It would also be the lowest water level since March of 2015.
— meteorologist Ross Ellet Facebook post

This sounds astonishing until you realize that Lake Erie’s water level fluctuates seasonally and is normally at its lowest in winter. You can see it on this GLERL graph comparing this year’s water level (2025 YTD in blue) to last year (2024 in red).

Great Lakes Water Level Dashboard, Lake Erie Master Gauge as of 9 Oct 2025 (GLERL NOAA)

Notice that the record maximums and minimums, shaded in pale blue, differ by 6.4 feet! Lake Erie has ranged about 3 feet higher and lower than it is today.

You usually experience these fluctuations only at the beach but I do remember flooded roads at Magee Marsh during high water in May 2019.

(water levels an Lake Erie beach at Long Point Provincial Park, Ontario from Wikimedia Commons at these links: low water wide beach in 2017, high water no beach in 2019)

Looking at the historical averages for the last five years, Lake Erie has been going down overall.

Great Lakes Water Level Dashboard, Lake Erie Long Term Record as of 9 Oct 2025 (GLERL NOAA)

But right now it’s at the 1918-2024 Long Term Average, so there’s nothing to worry about.

p.s. Speaking of worry, I remember when Lake Erie was very polluted in the early 1970’s. Fish died all the time and we did not wade or swim in it.

While looking for photos for this article I found a file photo from June 1973 with the caption: “WHITE CITY BEACH SIGN [Cleveland, Ohio] WARNS AGAINST SWIMMING IN POLLUTED LAKE ERIE. TO REDUCE POLLUTION LIFEGUARDS POUR CHLORINE INTO THE WATER ONCE EVERY HOUR.”

WHITE CITY BEACH SIGN [Cleveland, Ohio] WARNS AGAINST SWIMMING IN POLLUTED LAKE ERIE. TO REDUCE POLLUTION LIFEGUARDS POUR CHLORINE INTO THE WATER ONCE EVERY HOUR (photo from Wikimedia Commons)

Water pollution was so bad in the U.S. back then that it prompted the Clean Water Act of 1972. Only a year after the law was passed, Lake Erie was still in terrible shape because it took a long time to clean up.

Nowadays we take clean water for granted, but if the Clean Water Act is weakened we will slip back into the easy path of draining and dumping all kinds of yuk into the water.

Meanwhile it’s good to remember that “You don’t know what you’ve got til it’s gone.” — lyrics from Joni Mitchell Big Yellow Taxi

The Relentless Power of Plate Tectonics

October 8, 2025Musings & News, Spain, AndalusiaKate St. John

Flysch in the Mediterranean at Torre del Guadelmesi, Andalusia, Spain, 12 Sept 2024 (photo by Kate St. John)

8 October 2025

A year ago on a birding trip at the Strait of Gibraltar we stopped at the Torre del Guadelmesi a watchtower on the Spanish coast. Below us in the Mediterranean was an odd formation of parallel rocks called flysch.

Flysch is a sequence of sedimentary rock layers that progress from deep-water and turbidity flow deposits to shallow-water shales and sandstones. It is deposited when a deep basin forms rapidly on the continental side of a mountain building episode.
— Wikipedia: definition of Flysch

Here are two more examples near Tarifa, Spain.

Flysch at Parque Natural del Estrecho at the Strait of Gibraltar, Spain (from Wikimedia Commons)

Flysch at Parque Natural del Estrecho near the port of Tarifa, Spain (from Wikimedia Commons)

The layers erode at different rates so the formation looks striped. If it was not so eroded the rocks could look like this formation in Basque Country, northern Spain.

Flysch outcropping at Playa de Itzurun, Basque Country, Spain (photo from Wikimedia Commons)

What fascinated me was not the rock layers but the fact that they were tilted up, proving the relentless power of plate tectonics at the Strait. This animation shows how the horizontal layers became vertical.

Animated image of mountain formation by reverse fault (from Wikimedia Commons)

The Strait of Gibraltar is on the tectonic plate boundary where the African plate has been pushing into and under — subducting — the Eurasian plate.

Map of Mediterranean tectonic plate boundaries (from Wikimedia Commons)

The Eurasian and African plates are moving in generally the same direction but you can see on the map below that the African plate is moving a little faster so it is ramming into Spain.

Tectonic plates boundary types & movement from Wikimedia Commons

Geologists say that plate movement at the Mediterranean is complex and it has stalled so the plates may be changing places.

The continents are converging; and for many millions of years, the northern edge of the African tectonic plate has descended under Europe.

But this process has stalled; and at the European Geosciences Union (EGU) meeting last week [April 2011], scientists said we may be seeing Europe taking a turn.

If they are correct, this would signal the start of a new subduction zone – a rare event, scientifically fascinating.

“It looks possible that on the appropriate timescale, we are witnessing the beginning of subduction of Europe under Africa,” he told BBC News.
— BBC: Europe’s future lies under Africa, scientists suggest. 11 April 2011

When (or if) this happens, tilted rocks will rise on the African side of the Mediterranean. It will happen relentlessly but very very slowly. None of us will be around to see it.

The Petrel That Chases Hurricanes

October 7, 2025Bird Behavior, Water and Shore, Weather & SkyKate St. John

Desertas petrel (photo from Wikimedia Commons)

7 October 2025

We think of hurricanes as very dangerous and very devastating but there’s a pigeon-sized seabird, the Desertas petrel (Pterodroma deserta), who nests during hurricane season because it chases hurricanes to feed its chick.

High on a rocky plateau [on Bugio Island], one small nocturnal seabird is nestled in its burrow, where far below waves lap gently against the cliffs. In the blackness of night, it senses a storm brewing 1,000 miles (1609km) from the coast of Morocco.
— BBC: Riders on the storm: The birds that fly into hurricanes

Bugio Island, Portugal (photo from Wikimedia Commons)

Map of Desertas archipelago with Bugio Island (from Wikimedia Commons)

Bugio Island is well situated for chasing hurricanes, all of which are born as tropical depressions off the coast of Africa, travel west to the Americas, then swing north.

Tropical cyclone worldwide map from NASA SpacePlace

map embedded from Google Maps

When scientists put data trackers on Desertas petrels and tracked them for five years, 2015-2019, they found:

Desertas petrels make some of the longest foraging trips ever recorded in any species – traveling as far as 12,000km (7,460 miles) over deep, pelagic waters – all the way from Africa, to the New England coast and back again.
— BBC: Riders on the storm: The birds that fly into hurricanes

Unlike most seabirds who circumnavigate hurricanes or try to stay inside the eye of the storm, the Desertas petrel actively chases hurricanes, braves incredible winds, and captures food churned to the ocean’s surface in the wake of the hurricane.

They put themselves exactly in the right place at the right time to be run over by a hurricane.
BBC: Riders on the storm: The birds that fly into hurricanes. Quote from Francesco Ventura, Woods Hole.

Both parents forage, partially digest the food adding stomach oil, then regurgitate it into the chick’s mouth when they reach the burrow.

Chances are good that Desertas petrels were out there in the North Atlantic foraging in the wake of Imelda and Humberto last week.

Imelda-Humberto in North Atlantic, 5 October 2025, 6am (screenshot from earth.nullschool.net)

Unfortunately this amazing seabird is Vulnerable to extinction. There are only 200 breeding pairs in the world.

Read more at the BBC: Riders on the storm: The birds that fly into hurricanes