Every year, beginning in late August, broad-winged hawks (Buteo platypterus) head south on a 4,500 mile journey from their nesting territories in North America to their winter grounds in Central and South America. It’s a journey many of us witness at Pennsylvania hawk watches.
Unlike other hawks, broad-wings usually travel together. Though not in organized flocks they cue off each other to find the best travel conditions. This brings them together on migration.
The Allegheny Front Hawk Watch, 1.5 hours from Pittsburgh, saw 119 broad-winged hawks last Saturday but will peak September 13-15 with close to 2,000. Other Pennsylvania hawk watches will count even more.
Visit Hawkcount.org to see the latest statistics and find a hawk watch near you. Plan a visit soon.
Who knew that millipede bodies move vertically as they walk? Who knew that their antennae tap in time to their steps?
Diplopoda or millipedes are a class of 12,000 arthropods with two pairs of jointed legs on most of their body segments. Though mille means a thousand, Wikipedia says that none of them have that many legs. The record is 750.
Millipedes are susceptible to drying out so they live where it’s cool and moist, especially under leaf litter. They’re active at night but you might see them at dusk or on a very damp day when they come out to forage for decaying leaves, decaying plants or fungi.
They can’t bite or sting so their only defense is to curl in a ball and, when really irritated, release a stinky liquid.
At certain times of the year millipedes become restless and migrate from their normal living places; they [may] appear in window wells, basements, garages and other places where they become an annoyance.”
This restlessness usually has to do with mating. The crowd was looking for a cool damp place and made a mistake.
Don’t be alarmed. It’s too dry for them indoors. Penn State says, “Since millipedes do not live for more than a few days indoors, treatment inside the home is not necessary. Vacuum or sweep millipedes into a dust pan for removal.”
Of course, you’d have to get really close to a millipede to see this.
I’m not ready for that yet.
(photos from Wikimedia Commons; click on the captions to see the originals. Video shared on Twitter by @DickKingSmith; video originally by Crystal Albright a.k.a. Chris Dull on FB)
p.s. The photos in this article are of a single species found in eastern North America, the American “giant” millipede, Narceus americanus. I’ve seen them in Pennsylvania.
Yellow-crowned night-heron in Duquesne, PA (photo by Oliver Lindheim)
In August 2019 a rare bird showed up every evening at an industrial park in Duquesne, PA. The bird was outside his normal range, but this is not surprising for a juvenile yellow-crowned night-heron.
Yellow-crowned night-heron in Duquesne, PA, 18 Aug 2019 (photo by Amy Henrici)
Related to egrets and bitterns, yellow-crowned night-herons (Nyctanassa violacea) live near water and eat mostly crustaceans. Some live year round in Central and South America. Others breed in North America and migrate south for the winter as shown on the map below.
However, juvenile yellow-crowned night-herons are great wanderers. As Cornell Lab’s All About Birds explains, “After the breeding season, young birds often disperse to the north or west before heading to wintering grounds.” That’s how they end up in Newfoundland, North Dakota and Duquesne, PA.
At 4pm on Sunday August 18, I went to see him at the industrial park but he wasn’t there because (duh!) he’s a night-heron. So I went back at 7:20pm.
He attracted a small crowd. Five of us watched him roam the sidewalks and grass beneath the pine trees at American Textile Company. He was so unafraid of humans that he walked right past two people standing on the sidewalk. This bird is completely focused on cicadas.
Yellow-crowned night-heron in Duquesne, PA, 18 Aug 2019 (photo by Amy Henrici)
To give you an idea how close he came, here are photos from Oliver Lindheim (at top) and Amy Henrici, two of the many birders who’ve made the trek to Duquesne.
Yellow-crowned night-heron in Duquesne, PA, 18 Aug 2019 (photo by Amy Henrici)
As soon as the glut of cicadas is over, this bird will be on his way.
UPDATE 26 August 2019: This bird is gone. He didn’t show up on the evening of August 21.
NOTE: If you went to see the yellow-crowned night-heron and you use eBird, please mark his location as the new “Stakeout” Hotspot created specially for him called “stakeout, yellow-crowned night-heron at City Center, Duquesne, PA.
Peregrine outside his window. Photo by Matt Orres, 21 August 2019
On Wednesday 21 August, Matt Orres emailed me two photos of a peregrine outside his window at the Union Trust Building. I knew it couldn’t be Louie (he died in June at age 17) but the next photo confirmed the bird’s identity.
Though her bands aren’t visible, the long dark flecks on her breast and the shape of her face indicate to me that this bird is Dori.
Dori up close, Downtown Pittsburgh, 21 Aug 2019 (photo by Matt Orres)
The intense wildfires in Alaska this summer are different than those we’re used to in the Lower 48. These were sparked by unusual weather, they’re harder to put out because the soil is burning, and they’re causing their own feedback loop.
When lightning starts a fire in the boreal forest or tundra it doesn’t just burn trees and shrubs. It also burns below the surface because the soil is like peat moss. These “underground” fires are extremely hard to put out.
And finally, the fires cause their own feedback loop. They’re generated by unusually hot weather and their byproducts — smoke and CO2 — result in more hot weather. The smoke deposits black soot on polar ice which makes it melt faster (warming the area) and the CO2 contributes to climate change. As the climate gets hotter it spawns more arctic fires.
This 13 August video from NASA tells more about the arctic wildfires and how they’ll affect us — both now and later.
This moth can remember what it learned as a caterpillar.
In 2008, scientists at Georgetown University exposed late-stage tobacco hornworm caterpillars (Manduca sexta) to a specific scent and trained them to avoid it with a mild shock. The caterpillars got the message.
Scientists had thought that metamorphosis changed the brain so much that moths would not remember their caterpillar past. However, the caterpillars that learned about the scent in their last instar remembered the scent when they became moths — and they avoided it.
I wonder if other butterflies and moths remember their final days as caterpillars. Perhaps this is how females know to lay eggs on their host plant. “Hmmm,” says the butterfly, “This smells like the plant where I was feeding before I could fly.”
If you’ve noticed a lot of traffic in the City of Pittsburgh and a few street closures in Oakland here’s why: This week is Move-In Day at every university in town — six of them.
Move-In Day is our annual human effort at something that hermit crabs do all the time. Because they outgrow their shells hermit crabs are frequently in the housing market. When lots of them need a new shell they get organized and all move-in at once. It’s called a synchronous vacancy chain and takes only a few minutes once it starts to roll.
Dress for the weather and wear comfortable walking shoes. Bring binoculars and field guides if you have them. If it’s hot be sure to bring water, sunscreen and a hat.
Visit my Events page before you come in case of changes or cancellations. The outing will be canceled if there’s lightning.
There usually aren’t many peregrine sightings in August, but we had a few from here and there.
Freeport, PA: On August 6 Sean Brady was canoeing down the Allegheny River on a group trip from Kinzua Dam to Pittsburgh when he saw two peregrines at the Freeport Bridge (Route 356). On August 15 Dave Brooke stopped by the Butler-Freeport Trail and got this photo of a peregrine perched on the bridge. It stayed there for at least 30 minutes. Perhaps it feels at home.
Here’s an aerial view of the Freeport Bridge from downriver …
If you go to Freeport, Dave provided this map showing where he stood to see the bird.
Map of Freeport peregrine location from Dave Brooke
Sharpsburg, PA: On the night of August 6, Sharpsburg Police rescued an injured adult peregrine near the corner of Main Street and 6th Street. (Update: I have since learned that this peregrine was so badly injured that it had to be euthanized.)
Injured peregrine rescued in Sharpsburg, 6 August 2019 (photo courtesy Sharpsburg Police Dept)
62nd Street Bridge from the Sharpsburg side (photo by Dan Yagusic, 2007)
This Google map shows where peregrines have been seen this year near the 62nd Street Bridge.
Hopewell, Virginia: On Monday August 12 my husband and I were the first car in line waiting 15+ minutes for the deck to lift while a boat passed under the Benjamin Harrison Lift Bridge in Hopewell, Virginia. This is the bridge where Hope, the resident female peregrine at the Cathedral of Learning, was born.
While we waited, a juvenile osprey perched very close to my side of the car. When the bridge deck finally started coming down (slowly!) a peregrine flew off the superstructure, zoomed right past our windshield and knocked the osprey off its perch. It then pumped out over the river and back up to the tower. Wow! So close! I was cheering!
Was that peregrine one of Hope’s parents? I don’t think so. Hope is 11 years old … but you never know.
p.s. It never occurred to me to take a picture of the osprey or the bridge until we were miles away. 🙁
(photos by Dave Brooke, Wikimedia Commons, Sharpsburg Police Department, Dan Yagusic and VA DOT; click on the captions to see the originals)
