Stirring up the pigeons in Cleveland, 2017 (photo by Chad+Chris Saladin)
17 November 2023
Can you spot the peregrine?
When peregrines are hungry, the birds they’d like to eat flock tightly and move as fast as they can. The denser the flock the harder it is for the peregrine to pick out a solo bird to catch for dinner.
In the photo above pigeons are flying crosswise to avoid an oncoming peregrine. Can you spot the peregrine in the picture?
Dunlin (Calidris alpina) are masters of tight flocking and evasive maneuvers when threatened from the air. In the video below by Pacificnorthwestkate (@pnwkate) the dunlin move like a murmuration of starlings as a peregrine harasses them. Can you spot the peregrine?
Notice how the dunlin flock winks off and on in the video, dark at one moment then so white they disappear. In winter plumage dunlin have brown-gray backs and white bellies. The flock changes color as the birds turn in unison in the air.
When peregrine falcons migrate down the Pacific Coast in autumn they often pause at Canada’s Fraser River Delta to hunt shorebirds. Pacificnorthwestkate (@pnwkate) filmed one working a sandpiper flock at Roberts Bank.
Peregrines on the hunt hope to separate a single bird from the crowd because they cannot catch anything in such a tight flock. When a lone bird can’t keep up it becomes the peregrine’s dinner.
A new study, published this month in Phys.org, looked at the interaction from the peregrines’ perspective and found that the falcons haze the dunlin flocks to keep them moving. Peregrine hunting success improved at the end of those 3-5 hours of continuous flying because the dunlin had to stop for a rest.
The hunting data showed that dunlins were at greatest risk of predation just before and just after high tide, and spent most of the riskiest period flocking. However, there was a sharp increase in kills two hours after high tide, because the dunlins were not flocking despite elevated risk. [They were resting.]
So the dunlin changed their behavior to avoid peregrine predation and the peregrines changed their behavior to wear out the dunlin. Peregrines have more stamina that dunlin.
Ecco watches while Carla preens, 15 Sep 2023, 3:54pm
16 September 2023
Yesterday Ecco and Carla spent lots of time hanging out together at the Pitt peregrine nest. The snapshot camera’s motion detector captured their activity.
Beginning at 3:50pm the pair spent 45 minutes together, bowing, preening, and watching. When Ecco left, Carla continued on the perch for another half hour, then stretched and departed at 5:00pm.
Two minutes later Ecco landed at the exact same spot on the perch. Because female peregrines are larger than males, the switch from Carla to Ecco made it look as if the bird shrank.
Ecco preened for more than an hour, then stretched and vaulted up to leave at 6:13pm. All told, the peregrines were present on camera for nearly 2.5 hours.
This slideshow shows 144 minutes of their interactions in only 1 minute and 15 seconds. If you miss the captions on the first pass, don’t worry, the slideshow repeats.
The National Aviary’s streaming camera is off for the season so the Pitt peregrines are virtually out of sight, but they are not off my mind. Every day I check the Cathedral of Learning’s ledges to see where they’re perched and I look at the snapshot camera in case they’ve been to the nest.
Activity at the nest picked up this week because fall is coming and migration is underway. The length of day is similar to spring and they’re taking an interest in songbird migration as prey flies overhead at night.
Ecco and Carla bowed at the nest three times yesterday, including an extended bowing session, to strengthen their pair bond and their claim on the nest.
All of Pitt’s resident peregrines(*) stay home for the winter and I expect Ecco and Carla to do the same. They don’t need to migrate because there’s plenty of food in the winter (pigeons and starlings) and their “cliff” is too valuable to lose by vacating it for six months.
So I’m still watching. The Pitt peregrines may be out of sight but they are not out of my mind.
(*) There’s a lot of history that allows me to say that. Peregrines have lived at the Cathedral of Learning for 22 years, spanning 8 adult birds.
Because the Pitt peregrines had no eggs this year I miss seeing their young on camera. To fill that gap I’ve been following the Fulham and Barnes Peregrines at Charing Cross Hospital in London, UK whose daily lives are chronicled by @FaBPeregrines.
Azina, Tom and their son P6T (named for his band number) are frequently seen on camera, even in late August. P6T’s dispersal from his natal site is on a later schedule than we’re used to in Pittsburgh.
Juvenile peregrines in Pittsburgh fledge in early June and leave in July. At Fulham and Barnes, P6T fledged in the fourth week of May and is still hanging around in late August. His persistence gives us an opportunity to watch a peregrine family in late summer when the youngster hunts on his own.
The whole family on the ledge for a very brief moment when Tom comes and snatches P6T's prey while P6T is busy annoying his mum 😉 (P6T had brought in that pigeon not long before that and eaten only part of it) pic.twitter.com/Srvl55fNIb
Each year the National Aviary falconcam at the Cathedral of Learning runs from February through July to cover the peregrine breeding season. Streaming ended on 31 July but just the day before, on 30 July, Ecco and Carla bowed for a long time at the nest and Carla occasionally ate some gravel. (*more information on gravel below)
The entire bowing session lasted 8 minutes but they paused a lot so I sped up the video to double-time. At 3 minutes in, it looks as if Carla has left but she’s merely off camera. As she comes close again Ecco resumes e-chupping and bowing. Finally Carla flies away and Ecco stands up straight to watch her leave.
Though the bowing looks like courtship they won’t be starting a family anytime soon. Ecco and Carla live at the Cathedral of Learning all year long and bow to strengthen their pair bond, even in July.
The pair is generally less active in the summer but they’ll perk up when fall migration begins in earnest as they watch birds flying south over Oakland.
This morning just after dawn I saw a peregrine fly by my window carrying prey to the Cathedral of Learning. I’m sure it was Ecco bringing breakfast to Carla. The pair is “in tune” as if it was nesting season. Ecco supplies Carla’s food and they bow at the nest several times a day, but I know there will be no eggs at the Cathedral of Learning this year. It’s too late to raise a peregrine family.
Today on Throwback Thursday I looked back seven years to find that the blog was All Peregrines All The Time in 2016. In this trip down memory lane, you might remember a few of these incidents from that June.
A moment of repose: Peregrine fledgling C1, 16 June 2016 (photo by Peter Bell)
One week later a banded female peregrine showed up on camera at the Cathedral of Learning nest. It was Magnum from the Neville Island I-79 Bridge territory where she had already fledged two young. (Click here or on the video screenshot for the story.)
A few days later Magnum left Oakland, Hope and Terzo paired again, and their fledgling grew up and left town.
This year, by contrast, is very quiet. Fingers crossed for a good season next year.
Dark brown female at Third Avenue Downtown, perched on Lawrence Hall, 5 June 2023 (photo by Jeff Cieslak)
11 June 2023
This spring Downtown Pittsburgh’s peregrines were so confusing that for two months we weren’t even sure of their age and sex. By now we know that the male at Third Avenue is Terzo and the dark brown bird is female. Why is this bird so dark? The mystery is intriguing.
Wrong ID for the dark bird: In early April Jeff Cieslak and I were both convinced the dark brown bird was a one-year-old male because we saw it enter the Third Avenue nest carrying prey even though the eggs had not hatched yet. After all, male peregrines bring prey to incubating females and immature birds have brown plumage … don’t they?
Solve the easy ID first: Who is the banded white-chested bird? Jeff Cieslak’s April and May photos show that the gray-and-white adult has black/red bands. Also, several viewers remarked that the bird’s face is like Terzo in other photos. This bird is the male, Terzo.
Terzo at Third Avenue Downtown perched on Lawrence Hall, 5 June 2023 (photo by Jeff Cieslak)
Is the dark bird immature? No. Adult plumage has horizontal stripes on the flanks and belly, immature plumage has vertical stripes. Compare these side-by-side adult and juvenile peregrines photographed at Third Avenue.
Comparing peregrine adult vs juvenile plumage: Adult plumage has horizontal stripes, juvie plumage has vertical stripes (photos digiscoped by Kate St. John)
Is the female completely dark brown? No. This photo of her back shows it is grayer in color than her belly.
Dark brown female is grayer on her back, 3 June 2023 (photo by Kate St. John)
Why is this bird so dark? I sent photos to Art McMorris, retired PA Game Commission Peregrine Coordinator, and asked: “This adult at the Third Ave nest site Downtown is very brown and not banded as far as we can see. It doesn’t have juvenile vertical stripes on flanks and chest. I don’t know what to make of this coloration.”
Art’s reply includes a Peregrine Reintroduction discussion in the third paragraph:
This is indeed a very puzzling-looking bird. I’m looking at these 3 photos and the photo Jeff Cieslak took on 4/14. All show the horizontal banding typical of adult peregrines, not juveniles. But it is very brown, atypical of adults. It is much grayer in the third photo you sent; nowhere near as brown but still very dark.
Structurally, it looks like a typical peregrine to me.
Taking all of this together, I’d say it is reminiscent of pealei [Pacific Northwest subspecies]. Pealei is non-migratory, so I wouldn’t suggest that it might be a bird from the Pacific Northwest, but pealei is also one of the 7 subspecies used for captive breeding and release. And occasionally genetic recombination in the wild population results in birds with unusual coloration. I know of 2 cases of peregrines that looked exactly like pure tundrius, but their parents had the typical appearance of the re-introduced population, which strongly resembles eastern anatum (but is not anatum; it’s an intergrade of the 7 subspecies). One of those tundrius look-alikes was from the Gulf Tower, quite a few years ago when the population was still small.
So, my best guess is that this bird is an adult peregrine in which recombination has resulted in homozygosity of some alleles from its pealei ancestors. And the downtown bird is fertile, inconsistent with it being any kind of hybrid.
It will be interesting to see what this year’s young look like when they molt into adult plumage. But unfortunately, we’ll never know.
— Paraphrased email from Art McMorris, 4 June 2023
What other clues do we have about this bird? Art has so much experience with peregrines that he also said: “Earlier the brown bird was called the male, but the feet look female to me.”
Yo! Big feet?!
Dark adult peregrine at Third Avenue, 28 May 2023 (photo digiscoped by Kate St. John)
Just when I think I’ve got it all figured out, peregrines surprise me again.
Fledgling peregrine on the dog park windowsill (only 2 feet up), 5 June 2023 (photo by Leslie Mcilroy via Mark Catalano)
7 June 2023
At 6:30pm on Monday 6 June, Mark Catalano of Wildlife In Need Emergency Response was working dispatch in Central PA, making phone calls and sending texts and emails on behalf of a juvenile peregrine in a tiny dog park in Downtown Pittsburgh. The juvie needed assistance to be placed up high to start over on his first flight. Meanwhile Leslie McIlroy was in the dog park, protecting the bird from the visiting dogs.
Fledgling peregrine at the dog park on Third Avenue, 5 June 2023 (photo by Leslie Mcilroy via Mark Catalano)
Mark called the PA Game Commission but he knew it would be a long wait for a Game Warden. Since Mark is from Northumberland, PA he didn’t know any local peregrine contacts so he asked his wife to search the Internet for “Pittsburgh peregrine.” She found me, Mark sent me photos, and I told him about the Rescue Porch.
The Rescue Porch is a high balcony across the street at Point Park University’s Lawrence Hall. Another juvie had already tried it out this week, as seen by Diane Walkowski and Lori Maggio at 1:30pm on Sunday 4 June. (White arrow points to the bird.)
Juvenile peregrine calls from the Rescue Porch at Third Avenue, 4 June 2023, 1:50pm (photo by Lori Maggio)
Monday’s bird was stuck in a place I’d never heard of. It turns out that this narrow space under construction in 2021 became a tiny dog park with a tiny patch of grass. The yellow arrow points to a 2021 juvie who eventually landed in here. This year’s juvie hopped up to the low windowsill on the righthand wall, only two feet off the ground (photo at top).
Future dog park under construction on Third Ave, June 2021 (photo by Kate St. John)
Many thanks to Mark Catalano for starting the rescue and to Leslie McIlroy for guarding the bird until the Game Warden arrived three hours later.
Meanwhile, no news is good news. Sunday’s bird is out and about. Monday’s bird probably flew on Tuesday. Will the third youngster need a rescue too? Time will tell.
Peregrine falcons have nested in Downtown Pittsburgh since 1991 and though the players have changed they are very loyal to the territory. From 1991-2011 they nested at the Gulf Tower but since 2012, with three exceptions, they have nested at the back of a building facing Third Avenue. 2023 is their ninth nesting season at this site.
Yesterday morning I stopped by Third Avenue to see if any peregrines were visible and was lucky to see the entire family. Three youngsters perched at the ledge opening (photos at top) while their parents watched from above on the crossbars. The brown youngsters are exercising their wings and will fledge this week.
Downtown peregrine nest area as seen from Third Ave. Locations of birds noted in white. 3 June 2023 (photo by Kate St. John)
The adults have been a mystery. On 3 March Jeff Cieslak photographed an adult-plumaged pair: an unbanded female (not 16-year-old Dori who was banded) and a male who did not show his legs. When Jeff returned on 14 April he saw a nest exchange that appeared to be a male (unbanded in dark brown immature plumage) bringing prey to a female (banded & in adult plumage). The behavior told us who was who. Or did it?
Here are photos of the adults.
Adult-plumage bird on 18 May and 3 June 2023. Jeff re-checked his photos and saw that this bird has black/red bands and several viewers have remarked that the bird’s face is like Terzo’s. This is the male, Terzo.
Adult plumage peregrine at Third Avenue, 18 May 2023 (photo by Jeff Cieslak)Adult plumage peregrine at Third Ave, 3 June 2023 (photo by Kate St. John)
Photos of the dark brown bird on 28 May and 3 June 2023 are more of a mystery. The flank stripes are horizontal so this is adult plumage. This dark brown unbanded bird is the female. More on her color in a future article.
Dark plumaged peregrine at Third Avenue Downtown, 28 May 2023 (photo by Kate St. John)Dark plumaged peregrine at Third Avenue Downtown, 3 June 2023 (photo by Kate St. John)
Stop by Third Avenue in the next few days to see the youngsters fledge.
