Category Archives: Crows & Ravens

Counting Crows? Crows Can Count

Is this crow counting something? (photo from Wikimedia Commons)

20 November 2024

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.

SMithsonian Magazine: Crows Can ‘Count’ Up to Four Like Human Toddlers, Study Suggests

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.

Maybe I’ll have a chance to try this some day. Meanwhile, read more about the study in Audubon Magazine: Crows Can Count Aloud Much Like Toddlers, New Study Finds.


(*) 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!

Suddenly You’ll See a Lot of Crows

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.

Merlin versus Crow: How to Win a Nest

Merlin, eastern US (photo by Wm.H. Majoros via Wikimedia Commons)
Merlin, eastern US (photo by Wm.H. Majoros via Wikimedia Commons)

29 October 2024

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)
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.

American crow and fish crow (photos from Wikimedia Commons)

A 2019 study presented at the Wilson Ornithological Society showed that if the merlin nest was successful, chances are the nest had been owned by American crows.

Merlin chicks in nest (photo from Wikimedia Commons)

Behavioral interactions between nest-parasitic Merlins (Falco columbarius) and nest-building Fish Crows (Corvus ossifragus) in a new zone of overlap explains that American crows and merlins have coexisted for millennia so they have forged a working relationship and can reach detente early on. One or the other cuts their losses and nests elsewhere.

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.

Seen This Week: Late Flowers, Acorns, Crows

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)

They’re Back!

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.

Ravens Can Imagine Thieves

Common raven (photo from Wikimedia Commons)

16 October 2024

Did you know that ravens have paranoid, abstract thoughts about other minds?

A new(*) study has found that ravens are able to imagine being spied upon — a level of abstraction that was previously thought to be unique to humans.

WIRED, 3 Feb 2016(*)

Ravens are well known to cache food but who owns the stash operates on the principle: “Unless another raven is actively guarding it, whatever food I see is mine.” The finder eats or re-hides the cache. We would call this thievery.

To prevent thieves, a raven with lots of food waits until all the other ravens leave before caching his treasure. He’ll even go to a place where no one can see him hiding it.

Scientists thought that a raven had to see another raven before he went to all this trouble. Then a study in 2016 tested whether ravens can imagine potential thieves they cannot see.

The study, published in Nature Communications, found that if a nearby peephole was open, ravens guarded pockets of food against discovery in response to the sound of other birds — even if they didn’t see another bird. This was not replicated when the peephole was closed, despite hearing the same auditory clues.

Ravens are so smart that they can imagine thieves, just like we can. Is it a blessing or a curse to be this intelligent?

Watch how ravens imagine what another raven is thinking in this video from BBC Earth.

video embedded from BBC Earth

Today is the Day For Crows With Red Beaks

Red-billed chough, headshot (photo from Wikimedia Commons)

15 September 2024: Day 9, Ronda and the Sierra Grazalema Mountains, WINGS Spain in Autumn Click here to see (generally) where I am today.

It’s been nine years since I first became fascinated by the long curved bills of the “crows with red beaks.” Today I am in red-billed chough (Pyrrhocorax pyrrhocorax) territory in Spain, home of this Life Bird.

Red-billed choughs, pronounced “chuff“, are native corvids in Europe, Asia and North Africa but they are essentially sedentary. They don’t migrate so I have to visit their homeland if I want to see them.

Their favorite habitats are coastal cliffs and mountain meadows strewn with boulders where they poke their beaks into grass and soil to find insects. They will also forage in grassy areas in mountain towns.

Red-billed choughs roost on the cliffs of Ronda where we are staying two nights. They arrive before sunset in the cliff valley spanned by the Puente Nuevo bridge, right of center in the photo below.

Ronda and Puente Nuevo bridge (photo from Wikimedia Commons)

Here they are in a similar setting in Cadiz.

Just like crows, choughs assemble in flocks and make a lot of noise. However, choughs sound different from crows. Their name “chough” is supposed to mimic the sound but nothing can quite compare.

Red-billed choughs at Parque Regional Sierra del Carche, Spain (video embedded from Canal Natura on YouTube)

In North America people claim to have seen red-billed choughs in the wild but we don’t have them. Read about it in this vintage article, especially the comments.

Crow in a White Vest

Pied crow crowing (photo from Wikimedia Commons)

4 February 2024

Any day with a crow in it is full of promise.

Crows: Encounters with the Wise Guys, by Candace Savage

Crows are a favorite theme of mine so I was pleased that we encountered Africa’s most common crow at nearly every birding site on our trip in southern Africa. We saw only one Corvus species, the pied crow (Corvus albus). He wears a white vest.

Pied crows are intermediate in size between crows and ravens and are closely enough related to Africa’s dwarf raven, the Somali crow, that they can hybridize. However their behavior is closer to that of American crows (Corvus brachyrhynchos).

Pied crows on left, American crows on right (photos from Wikimedia Commons)

Wikipedia says the same of both of them.

The pied crow‘s behavior is more typical of the Eurasian carrion crow.

American crows are the New World counterpart to the carrion crow and the hooded crow of Eurasia. They all occupy the same ecological niche.

Both are smart and inquisitive.

The pied crow’s voice is intermediate between crow and raven.

Typically we saw only one or two crows at a time except at dawn when they left their roost. Then my highest count was eight.

Pied crow in flight, composite of same crow (photo from Wikimedia Commons)

The main difference between pied and American crows appears to be that pied crows don’t migrate and are less gregarious. As far as I know they never aggregate into huge flocks.

Africans would be surprised, and perhaps horrified, to see Pittsburgh’s flock of 20,000 American crows in winter.

(photos from Wikimedia Commons)

Counting Crows: 15,000

Crows coming in to roost at Robinson Ext & Vera, 31 Dec 2023 (photo by Kate St. John)

31 December 2023

Success! Last night, Saturday 30 December, our team counted 15,000 crows at their roost on Robinson Ext and Brackenridge Streets during the Pittsburgh Christmas Bird Count (CBC). It was a big challenge compared to last year when we could stand in one place and count 20,000 flying by in the distance. This year we had to chase them for two hours, texting each other with updates, until the crows finally picked a spot. In darkness and rain we think we were unable to see another 5,000 but we can’t count what we can’t see. So the official count is 15,000.

Carol Steytler, Sue Faust and I did a dry run on Friday night. That evening the western stream flew over the Allegheny River to stage at Cliff Street before moving on. My brief video shows how impossible it is to count them before they settle.

video by Kate St. John

That night we followed about half the flock to Wylie Avenue near Lawson, but where did the rest of them go? Fortunately it was just a dry run before Count Day.

On Saturday night Claire Staples joined us for the CBC and we split up to find the crows. Sue waited for them on Arcena Street but not a single crow came to the bluff above Bigelow. Carol found them staging near Wylie and Herron but when Claire and I caught up we could tell the crows were going to leave; there are no streetlights on that patch of woods.

By 5:30pm the crows had picked a roost and we gathered near Vera Street to watch them swirl overhead in the rain. We counted them in trees and on the Sports Dome but could not see how many were on nearby roofs and other places out of sight, so the official count is 15,000. Maybe next year we’ll count all of them.

Thank you to the intrepid team — Carol Steytler, Sue Faust and Claire Staples — who braved rain, cold, and darkness to count the crows. We were up for the challenge and we found almost all of them. And thanks to my readers for your tips and sightings. We’re done now until next year. 🙂

And we’ve learned a valuable lesson: If you want to count crows, don’t expect to find them in the same place or even flying the same route every night.

(photo and video by Kate St. John)

Only 3 Days To Find the Crows!

American crow closeup (photo from Wikimedia Commons)

27 December 2023

This Saturday, 30 December, is Pittsburgh’s annual Christmas Bird Count when we confirm the number of crows that come to town for the winter. Usually the count is 20,000 so after they skunked me three years ago (I counted only 220!) it’s been my mission to find the roost and count them all.

Last week I was confident that, thanks to you, we had found the crows. Carol Steytler saw them roosting near Heinz Lofts on 16 December so I went down there on the 19th — before I left town for the holiday — and saw more than 10,000 streaming in from Troy Hill to Heinz Lofts. I thought the Crow Count was going to be easy.

Hah! The crows have something else in mind.

Crows roosting at Allegheny River near Heinz Lofts, 7 Feb 2021, 7:40pm (photo by Kate St. John)

On Sunday 24 December Carol told me the crows were GONE! They weren’t near Heinz Lofts and when she drove around yesterday from 5-7pm she couldn’t find them anywhere!

Are we going to let 20,000 crows avoid the Count? No!

If you see a steady stream of crows at dusk please tell me where you saw them and where they were going.

Crows streaming past near Troy Hill (photo by Jeff Cieslak)

If you see crows at sunset making a racket in the trees, please tell me where they were!

There are only 3 days left until Pittsburgh’s Christmas Bird Count and (yikes!) I’m still out of town. Please help me find the crows!