Snow in Schenley Park, 20 Dec 2024 (photo by Kate St. John)
22 December 2024
In the run-up to the winter solstice the temperature dropped below freezing last week and the clouds moved in. Seen last week includes evidence of deer, snow and crows.
Evidence of deer: After the city parks bow hunt began in September the deer found other places to hang out including cemeteries and backyards. But we still see their evidence of their nighttime presence including this buck rub in Frick Park on 19 December.
Buck rub on a tree in Frick Park, 19 Dec 2024 (photo by Kate St. John)
Snow fell on Friday and Saturday. In this video its starts out a bit furious and then tapers.
Snowing in Pittsburgh on 21 Dec 2024 (video by Kate St. John)
Our search for the Pittsburgh crow roost continues. We need to find as much of it as we can before the Pittsburgh Christmas Bird Count on Saturday, 28 December. So far we haven’t broken 10,000 but we know there are more than that.
Though crows prefer to spend the night in trees we’ve discovered they also roost on rooftops in Oakland where we cannot see and count them. Dang!
Last night Carol Steytler found some near the Pitt Field House. Not a huge number, but encouraging. Her video is dark; it was the middle of the night.
Please help us find the crows. Leave a comment to let me know where you see lots of crows after 4:00pm in the city limits. Tell me about …
Huge flocks of crows
Seen after 4:00pm or Overnight
Where are they? Provide specific location, street or landmark.
If flying, what direction are they going? I’ll map your contribution and triangulate.
Winter crows are incredibly persistent. Year after year they return in large numbers to the same city, even if the city harasses them. Some cities harass their winter crows, some celebrate them. This is a Tale of Two Cities from the winter crows’ perspective — Rochester, New York and Lawrence, Massachusetts.
From the crows’ perspective, smaller units won’t provide safety in numbers so the crows will reconvene somewhere. But where? Will the new location cause trouble, too?
Rochester could choose a more permanent solution by “thinking like a crow.”
Penn State University used to have a big crow problem in the center of campus. In 2009, with the help of crow expert Margaret Brittingham, they picked a location away from people where they wanted the crows to roost. Since crows want to sleep with the lights on, Penn State floodlit a remote set of trees and harassed the crows away from the people zone. The crows moved to the floodlit site and abandoned central campus. Not only that, the crows passed on information about the new roost from crow to crow year after year and continued to use the new roost, not the old one. Ta Dah! Read more at Penn State relocates its winter crows.
Tens of thousands of crows visit Lawrence, Massachusetts every winter but as far as I can tell they have never been harassed there. Instead the roost is celebrated as a tourist attraction, described on the Winter Crow Roost website and YouTube channel.
Nov. 18, 2024: Join us for an unforgettable evening on Crow Patrol under clear skies (55°F, NW winds at 15 mph) as we explore the Merrimack River staging area east of Rt. 495. Witness the incredible sight of American and Fish Crows vocalizing and converging into tree tops in a wild, dramatic display at the east end of Island Street.
Don’t miss this breathtaking show of nature in action! Watch now and share with friends who love the beauty and mystery of wildlife.
So from the crows’ perspective, you’d rather choose Lawrence, MA over Rochester, NY.
(*) p.s. Rochester’s crows are never going to switch to Lawrence MA. They come from different parts of the continent: Lawrence = Atlantic coast. Rochester = interior and south of Hudson Bay.
Crows stream by in Oakland, 4 Nov 2016 (photo by Kate St. John)
15 December 2024
For stirring winter wildlife spectacles in our own backyard it’s hard to beat Pittsburgh’s winter crow roost. Once you’ve seen them you can’t help but wonder: How many crows are there? In less than two weeks, if we’re lucky, we’ll find out.
On Saturday 28 December volunteers will fan out across the 7.5-mile radius Pittsburgh Christmas Bird Count (CBC) circle to tally all the birds they see in 24 hours. It’s the perfect time to count crows but it takes a team to do it. How do we count crows?
First, Find the Roost. Top Priority this week.
The best way to find all the crows in one place at one time is to count them entering, exiting or perched at their massive communal roost. But they change their roost often in late December. I need your help finding it.
Let me know where you see lots of crows after 4:00pm in the city limits. Tell me about …
Huge flocks of crows
After 4:00pm or Overnight
Where are they? Provide specific location, street or landmark.
If flying, what direction are they going? I’ll map your contribution and triangulate.
When To Count? Dusk.
For the CBC we (the crow count team) arrive in the target area around 4:15pm (45 mins before sunset) and count until it’s too dark to see, around 5:45pm (45 mins after sunset). Most of the crows come in after 5:20pm.
If we’re not sure where the roost is (oh no!) we follow the crows by car to the point where they congregate. This is a nerve wracking activity because crows do not fly the street grid.
If we know where the roost is (ideal!) we assemble at various vantage points to view the roost.
Estimate!
Are we counting every single crow? No way!
Estimate the number of crows in a particular patch of sky or a section of the roost, then multiply by the number of patches. This takes practice. Try it out this week.
Count by 10s or — when it’s intense — by 100s.
In Flight
Crows streaming overhead on their way to the roost, 1 Nov 2024 (photo by Kate St. John)
If you’re on a crow flight path after 4:00pm you can count them as they go by. However, a vantage point underneath the stream (photo above) is basically impossible to count.
Find a straight edge boundary and count them as they pass the edge. The edge in this photo is a signpost. A sparse flock like this could be counted by 10s.
Crows flying to the roost, 4 Nov 2013 (photo by Kate St. John)
For the CBC we don’t want to double count so we find the roost and note the flight paths. If the flight paths have good vantage points we count there. This takes additional volunteers.
Dr. Wacker presented information on crow vocalizations at the Olympic Peninsula Audubon Society in November 2024. To measure the calls they analyzed these components.
The team recorded crow vocalizations in various contexts and compared the spectrograms. And they discovered an unusual thing. Crows appear to be “saying” things in the silence between their caws (gaps) and the pauses between their calls.
Gaps between caws: Are longer in pre-roost aggregations (evening) than in post-roost aggregations (morning).
Pauses between calls: Are shorter while mobbing an owl than in pre-roost aggregations.
If you want to know what a crow is saying, listen to their silences.
Learn more about crow language in this Olympic Peninsula Audubon Society’s video. I have set it to start nearly an hour into the meeting, beginning with spectrogram analysis of crow calls. I’ve included this 15 minute portion here because it is so interesting. Click here to see the entire 1.5 hour meeting.
p.s. Dr. Wacker described an intriguing idea: The messages in human language come from our sounds. The messages in crow language appear to come from silences. Perhaps we can’t figure out what crows are saying because we aren’t used to listening to the silences.
Crows staging at Schenley Park golf course at sunset on 30 Nov 2024, 4:57pm (photo by Betty Rowland)
6 December 2024
Since late October visiting crows have been pouring into town to join Pittsburgh’s enormous winter crow flock. Their numbers in Shadyside and Oakland grew from 3,600 in mid-October to over 8,000 in mid-November … and then I lost track of them because they moved the roost and changed their flight path.
Alas! The flock is still growing — perhaps to 20,000! — and just three weeks from now on Sat. 28 December will be the annual Pittsburgh Christmas Bird Count (CBC) when we’ll confirm the number of crows that come to town for the winter. If we can find them.
I had hopes last Saturday 30 November when Betty Rowland saw a huge flock staging at Schenley Park’s golf course, photo above. But when Betty checked again on Monday the crows were completely gone.
Our winter crows change or split their roost often in late December because they wear out their welcome so quickly. (See examples here.) So where are they now?
Please help. Let me know where you see lots of crows just before sunset or at night in the city and/or Allegheny County. Tell me about …
Huge flocks of crows
After 4:00pm
Where are they?
If flying, what direction are they going?
Your sightings are especially important in the week before the CBC, December 22-27.
To get you in the mood, here’s a video from Winter Crow Roost in Lawrence, Massachusetts where they’ve ramped up crow counting with photography and videos. Woo hoo!
The number of crows in the East End increased recently after they began roosting at Pitt again. On Saturday night I saw hundreds of crows in the trees at Carnegie Library and the Cathedral of Learning so on Monday afternoon I did a walk-about to count “crow trees” that showed evidence of roosting. (A big tree holds 250 crows.)
Crows gathering at dusk in Schenley Park, 21 Jan 2017 (photo by Mike Fialkovich)
My tree count was way too high so on my way home I paused at Fifth and Craig to count the huge flock passing overhead on their way to Pitt. 8,000 to 8,500 crows.
On Tuesday evening I could see crows staging in the trees above Morewood Ave so I counted again. 8,000 crows. … And this is just the East End flock.
The crows may be wondering why I’m counting(*), but crows can count too though not so high. A study of carrion crows (Corvus corone), published in Science last May, showed that this Eurasian equivalent of the American crow can count up to 4 out loud, similar to human toddlers.
Three carrion crows were trained to vocalize with one, two, three, or four caws depending on the number they saw in front of them. They were also taught to tap the screen when they were done counting.
The birds boasted a 100 percent accuracy rate at counting to one, a roughly 60 percent success rate at counting to two and about a 50 percent accuracy rate for three.
Crows particularly “disliked” the number four (40 percent accuracy), sometimes refusing to caw at all when prompted and pecking at the screen to end the trial immediately, [according to] study co-author Diana Liao, an animal physiologist at the University of Tübingen.
Additionally, the crows paused before cawing correctly, showing longer reaction times before producing higher totals of vocalizations. This delay is consistent with mental planning.
The test reminds me of a story Chuck Tague told me many years ago. He and his wife Joan visited a bird blind to see an elusive bird that would not come out if a crow was watching. Unfortunately whenever he and Joan went to the blind a crow would follow them and wait for them to leave.
They decided to fool the crow. Both of them went into the blind but only Chuck came out. Surely the crow would leave and Joan would see that elusive bird. Nope. The crow counted two people going in and only one came out. They changed it up and Joan came out but it made no difference. The crow could certainly count two people.
(*) p.s. I’m counting crows to get in practice for the Pittsburgh Christmas Bird Count on 28 December 2024, the Saturday after Christmas. Last year we counted 15,000!
Crows at the roost, 30 December 2023 (photo by Kate St. John)
4 November 2024
Pittsburgh’s winter crow flock is building as more birds from the north join the thousands already here. By the end of December at the Pittsburgh Christmas Bird Count, there will be as many as 20,000 crows on the move at sunset.
This month while the flock is growing, the roosts that were adequate in October are too small, so they move the entire roost or split into several locations. The moving or splitting happens every week, if not more often.
On Halloween they chose a favorite spot in the Hill District overlooking the Allegheny River, but those coming from the southeast had to change course to get to it. Thousands flew over my apartment building just after sunset on 1 November. On 2 November they found a shortcut and took a different route.
Winter crow flock flies to the roost, Pittsburgh, 1 Nov 2024 (video by Kate St. John)
Tonight sunset is during rush hour at 5:12pm and for the first time this fall many people will be outdoors while the crows are on the move. Those who hadn’t noticed the flock before will think the crows suddenly showed up. Nope. Crows have been traveling at sunset all their lives. It’s the people who suddenly showed up.
p.s. Thank you to Sue Faust & Betty Rowland for alerting me to the crows’ whereabouts. It’s always a challenge to find the roost, especially in late December.
Last spring during the nesting season I was so distracted by peregrines that I neglected to check on a merlins’ nest reported in Highland Park. By the time I got over there the young had fledged, the merlins were gone, and a small group of American crows were inspecting the area and commenting on what they found.
Crows are intensely interested in merlin nests because those nests may have been stolen from crows.
Merlins (Falco columbarius) never build a nest. Instead they search for crow or hawk nests, ideally in conifers, and take them over. If the target nest is unoccupied no problem but merlins are feisty and will try for an active crows’ nest by driving off the incubating female crow. If harassing her doesn’t work, they shout at her all day until another predator shows up and forces her to leave.
This often works because merlins are loud and fearless. They’ll drive away anything that irritates them including this raven (a merlin predator not a competitor).
Merlin attack! Raven flips upside down, Renews, NL, 10 July 2010 (photo by Trina Anderson)
However, in southwestern Pennsylvania there are now two species of crows — American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus) — and it makes a difference to the merlins’ success.
Not so with fish crows. Merlins and fish crows are new to each other so they haven’t worked out their differences and continue harassing for a much longer period. Few or none on either side have a successful nest. In the study of 25 fish crow nests in upstate New York, 40% failed due to merlin interference. The study tracked 31 merlin nests and found 66% of those made in fish crow nests did not fledge young.
Autumn and winter are good times for seeing merlins and fish crows in Pittsburgh. It would be interesting to find them interacting in spring and watch what happens.
p.s. Thank you to Don Nixon of PA Merlins for alerting me to this fascinating topic. The paper(*) is by Connor O’H. Loomis and Anne B. Clark (Binghamton University), John Confer (Ithaca College), Kevin J. McGowan (Cornell Lab of Ornithology) but it is behind a pay wall. The fish crow and merlin nesting studies continue beyond 2019 in Ithaca, NY at Cornell Lab of Ornithology.
Insect on New York aster, Toms Run, 16 Oct 2024 (photo by Kate St. John)
19 October 2024
This week brought:
Fall colors and the first piles of fallen leaves
Late flowers and insects
“See Your Breath” cold mornings
The first juncos … and …
Several thousand crows in Oakland.
In photos, late asters attracted an insect at Toms Run and morning sun slanted through the trees in Schenley Park.
Fall colors and fallen leaves, Schenley Park, 18 Oct 2024 (photo by Kate St. John)
Many trees are changing color. The oaks aren’t there yet but they have dropped their acorns leaving empty acorn cups on the branches. It’s a big mast year for red oaks in Pittsburgh.
Red oak leaves and acorn cups, 13 October 2024 (photo by Kate St. John)
A rhododendron in Shadyside is confused. Is it spring?
Confused rhododendron blooming in Pittsburgh, 13 Oct 2024 (photo by Kate St. John)
This week crows were absent from Oakland during the day but arrived in huge flocks at dusk, staging on rooftops before flying to the roost. I fumbled to photograph them on the RAND Building last Sunday. This is only a fraction of the flock that flew away.
Crows make a stop on the RAND building before sunset, 13 Oct 2024 (photo by Kate St. John)
Obviously they’ve been roosting on Pitt’s campus. I found evidence below trees at the Pitt Panther statue. The Crows Slept Here Last Night.
Evidence at Pitt that The Crows Slept Here Last Night, 17 October 2024 (photo by Kate St. John)
Crows bursting off a tree along Forbes Avenue (photo by Kate St. John)
17 October 2024
The crows are back in town!
On 1 October I counted 1,800 crows staging in Shadyside before they flew west to a roost. Last night I counted twice as many heading toward the Cathedral of Learning. 3,600 is only a fraction of the flock that will be in Pittsburgh by the end of December. As their numbers grow they quickly wear out their welcome. That’s when they move the roost.
In transit a flock this large is kind of mesmerizing (video from Dec 2023).
Crows flying toward the roost, December 2023 (video by Kate St. John)
But if they sleep in your trees they are really messy.
Evidence that crows roosted in the trees above this sidewalk, 7 Nov 2020 (photo by Kate St. John)
On Monday I saw Pitt’s maintenance staff spray-washing the sidewalk on Bigelow Blvd and I found “poot” evidence across the street as well. I’m sure Pitt is on the verge of moving them along, if they haven’t already done so.
Last year Pitt used flashing lights to convince the crows to leave the Bigelow Blvd trees. Crows really hate strobe lights.
Pitt works to move the crows, 13 Nov 2023 (video by Phillip Rogers)
I suspect there were strobe lights last night because … When the crows sleep near the Cathedral of Learning I live in their flyway. Last night thousands flew past my window but this morning none of them made the return journey. So did the crows sleep at Pitt? I wonder.
This tug of war with winter crows happens every year. They might end up roosting where the whole flock can sleep without bothering anyone, or they might split the roost to reduce their impact. One thing I know for sure. The crows will be hard to find for the Christmas Bird Count. 😉
UPDATE 17 Oct, 1:30pm: The crows *did* sleep in the trees at Pitt. I saw the evidence this morning.
