The term Polar Vortex came into popular use about 12 years ago when Earth’s normally well behaved jet stream went wobbly and forced arctic air into the continental U.S. The high temperature map on 6 January 2014 indicated -20°F in Minnesota!
U.S. maximum temperature map for January 6, 2014 (graphic from NOAA)
This week forecasters are talking “Polar Vortex” because the jet stream is wobbling again and we’re seeing the same effect. The slideshow at top is our low temperature series for today through next Tuesday 9 December. Pittsburgh’s highs will be below normal, hovering just above and below freezing.
It was much much colder in January 2014 but the difference this year is that it’s happening sooner, in some places setting temperature records for early December. And it repeats with very cold lows in Pittsburgh on the 4th & 5th, not so bad on 6th & 7th, and back again on 8th & 9th.
On Sunday at Duck Hollow we found hundreds of American robins loudly feasting on fruit in the ornamental trees and honeysuckle bushes. Flocks of 50 or more flew overhead heading south. Though I knew a snowstorm was coming in 36 hours I had not internalized it but the robins had. They were frantic to eat and run … or rather … fly south to avoid the storm.
The American robin (Turdus migratorius) flocks that visit Pittsburgh in November are on their way south, but slowly. They stay as long as there’s abundant fruit and the ground is not frozen or covered in snow. As soon as any of those conditions are met, they’re gone.
This time their departure was particularly abrupt. So many robins on Sunday, so few on Tuesday. No robins here among the snow.
Snow-covered tree on Pitt’s campus near Heinz Chapel, 2 Dec 2025 (photo by Kate St. John)
Watch American robins’ week-to-week movements throughout the year in this eBird Status and Trends animation. Notice how they breed in Alaska and Canada and abandon them in winter. They are among the big flocks see in Pittsburgh in the non-breeding season.
And though we see a lot of robins in late fall and early spring, they are sadly declining in spring and summer. If you live in a Midwestern state (Ohio, Indiana, Illinois, northern Kentucky, Michigan, Wisconsin) or in the I-95 corridor from Massachusetts to DC, American robins are trending sharply downward during the breeding season. In the decade from 2012 to 2022 losses were -10% to -14.8%.
Crows staging at Schenley Park golf course, 20 Nov 2024 (photo by Betty Rowland)
2 December 2025
This year’s official Crow Count will be on Saturday 27 December during Pittsburgh’s Christmas Bird Count. We know that our winter flock is 10,000 to 20,000 strong but crows are elusive. They were so sneaky in 2021 that I found only 1140. Right now we have just 25 days to crowd source their location. December is the month for crows!
Crows like to roost at the tops of mature trees and they want to sleep with the lights on so this tree near Thackeray Hall was perfect in November 2011.
Crows roosting near Thackeray Hall, November 2011 (photo by Peter Bell)
In late October this year they roosted at Pitt’s campus and somewhere in/near The Hill. On 29 October they staged outside my window before flying to the roost. Cool!
video by Kate St. John
But by mid-November they changed the roost and did not stage here anymore.
Pittsburgh’s winter crows are likely to change the roost tonight because it’s been snowing and they’ll want to sleep somewhere warm.
Snow at the Pitt peregrine nest, 2 Dec 2025, 8:45am (photo by Kate St. John)
Keep your eyes on the sky. Have you seen crows staging or roosting? Where and when? Did they leave? Which direction did they go?
Yesterday was cloudy and cold when seven of us gathered at Duck Hollow. While we looked for birds we found several surprises.
Six of us at Duck Hollow, 30 Nov 2025, 8:30am (photo by Joe Fedor)
Most amazing was the very fat rusty-orange fox squirrel (at top) who posed like a Buddha — the fattest squirrel I’ve ever seen. I’ll bet he’s overeating at a feeder in the Duck Hollow neighborhood.
The immature tundra swan first seen in mid-November was still present, though far across the river. After our group broke up Ed McKaveny crossed the Monongahela for a closer look.
That’s when I put in my Wish for two more raptor species including my favorite bird
We saw a red-tailed hawk, as I expected, but where was the peregrine I’ve seen at Duck Hollow since November?
After more than half the group had left, three of us were puttering in the parking lot when I saw a peregrine approaching from upriver. Ta dah! This bird has a full crop; none of the songbirds need to worry.
Lake Erie is the shallowest of the Great Lakes and can be very calm, but when the wind kicks up in November the waves start crashing and the lake reveals its hidden treasures.
On the day before Thanksgiving the wind blew steadily from the west-southwest at 25-30 mph, gusting to 50 mph in Ohio.
After that the wind died down and the lake sloshed back and forth like a bathtub. This effect is called a seiche. You can see this on the lake level graph, rising and falling stepwise after the high water mark.
Late afternoon light, Schenley Park, 23 Nov 2025 (photo by Kate St. John)
29 November 2025
This week I’ve spent a lot of time in the car for family Thanksgiving visits so I don’t have a lot of photos to show. Mostly pictures of the sky.
Sunset in Pittsburgh, 23 Nov 2025 (photo by Kate St. John)Sunset in Pittsburgh, 23 Nov 2025 (photo by Kate St. John)
We spent some time in Virginia Beach where there has not been a killing frost so flowers like this henbit deadnettle (Lamium amplexicaule) were still blooming.
Henbit deadnettle, Virginia Beach, 27 Nov 2025 (photo by Kate St. John)
On the bay shore boardwalk at First Landing State Park I found a lot of fallen acorns.
Acorn from a sand live oak, First Landing State Park, Virginia Beach, 27 Nov 2025 (photo by Kate St.John)
They are similar to southern live oaks but are very likely the sand live oak (Quercus geminata) that grows in sand and is commonly cultivated. It’s a good bet the trees were planted on the dunes. The leaves look like this.
Do you have cranberry sauce left over today? When I was growing up we had sauce-shaped-like-a-can and it was always leftover. Half the family was polite about eating it on Thanksgiving but would not eat it later.
It doesn’t have to look like a can. This sauce gives a hint of where it came from.
Wild turkeys (Meleagris gallopavo) practice polygyny — many females mated to one male. Their mating ritual requires that the males dance to attract females.
So why are these three, below, strutting together if only one will get to mate with the lady?
Males in wild turkey flocks are usually brothers who collaborate to attract the opposite sex. The less dominant brothers display but won’t become fathers … unless they sneak some action on the side when their brother is not watching.
We humans love to be near water, so much so that we build water features where they didn’t exist. We make backyard ponds, scenic ponds, and improve streams.
Garden pond (photo from Wikimedia Commons)Panther Hollow Lake, Schenley Park, March 2024 (photo by Kate St. John)Construction at Phipps Run, Schenley Park, 20 Nov 2021 (photo by Kate St. John)
All along I’ve suspected that these water features, though often beautiful, are not nearly as good as what nature creates. And now we know for sure.
Two studies find that beaver-engineered wetlands attract twice as many hoverflies, nearly 50% more butterflies, and a richer variety of bats compared to human-made ponds or free-flowing streams.
A week ago I was thrilled to see a raven “herding” a red-tailed hawk into my Oakland neighborhood. The raven had claimed the airspace over the Bloomfield side of the East Busway and was making the hawk fly back to where he came from. No red-tails welcome here!
We have so few ravens in Pittsburgh that I rarely see this kind of action but if I lived in California, as Vance Crofoot does, I’d have a lot of opportunities to watch raven territorial behavior against predators and other ravens.
In this three minute video you’ll see a raven defending his territory against an intruding male. It’s amazing that both birds posture and make soft sounds rather than loud raucous noises.
You’ll also learn:
The size of a raven’s territory.
How you can tell which raven lost the confrontation.
