21 April 2024

This morning Carla periodically hunched over the eggs, rocked her body and appeared to vocalize to the eggs. This is typical mother peregrine behavior when she hears a chick hammering on its shell.

While hatching is underway the parent birds can hear the chick peeping inside the egg and can hear it the hammering on the shell. Hatching itself takes many hours but the first step we’ll see is a pip, an air hole that the chick punches to begin the process. Richmond Falconcam FAQ explains how long it takes for the tiny bird to hatch:

Hatching is an energetically demanding process. The young chick uses its egg tooth, a small knob on top of its bill, to hammer a pip (hole) in the egg. It periodically works to break the egg around the pip area, but rests much of the time. The entire process from initial pip to hatch can take up to 72 hours. All the eggs in a Peregrine Falcon clutch generally hatch “synchronously” (within 24–48 hours for a clutch of 4).

— Richmond Peregrine Falconcam FAQ

Watch for a pip at the National Aviary falconcam at Univ of Pittsburgh.

14 April 2024

The Sewickley Bridge has hosted single peregrines since 2017 but a pair was not regular there until early 2021. At some point observers noticed that one of the pair is banded but who could read the bands?

And where was this pair nesting on the bridge?

This spring Jeff Cieslak answered both questions. He photographed a nest exchange in which the male took over incubation and the female left the nest.

And he got a photo of the male’s bands.

[The male] was on the near tower so I only had to walk half-way across the bridge (so the sun was behind me). As soon as I stopped, he started to scratch his face, and his bands rotated enough and were focused enough that I think I can read them. They’re upside-down, so it’s “black 0 5 (or 6) over green S (or 5) 6.”

— Jeff Cieslak in Our Daily Bird, 4 Feb 2024

The bands are Black/Green 05/S and he used to nest at the Neville Island I-79 Bridge (a.k.a. the Glenwood Bridge) until it was boarded up for construction in 2020 for more than three years. At Neville Island I-79 he was nicknamed Beau by site monitor Anne Marie Bosnyak.

Beau didn’t move far to find a new nest site and he didn’t move far from his birthplace. He hatched at the Cathedral of Learning in 2010 to parents Dorothy and E2. I know for sure that he is 05/S because his brother 06/S, nicknamed Green Boy, died in the Webster Hall chimney in June 2010.

Beau is now 14 yrs old but he has longevity in his genes. His mother Dorothy lived to be 16 and his grandad Louie from Downtown lived to be 17 and bred successfully at 3rd Ave in his 17th year. (Beau’s father, E2, was hit by a car in 2016 so we’ll never know how long he would have naturally lived.)

Read about the first time we identified Beau, Black/Green 05/S, in this vintage article.

(credits are in the captions)

13 April 2024

On Thursday 11 April, before torrential rain and flash floods hit the Pittsburgh area, Dave Brooke went down to Tarentum to see the peregrine family at the Tarentum Bridge. His video shows the mother peregrine sheltering two chicks.

Not only are the chicks sitting up with their eyes open but their faces are distinct. My guess, based on the clues in Peregrine Chicks Week-to-Week Development, is that these chicks hatched around April 2.

This weekend would be a good time to see the chicks but keep in mind the Allegheny River is in flood because of Thursday’s record-setting rainfall. Here’s the flood stage upstream this morning at Natrona Lock and Dam.

The boat launch area under the bridge is certainly off limits, but that’s OK because the best place to view the nest is on the sidewalk on First Avenue at Wood Street, the right hand pin drop on this map.

Bring a scope if you have one. You’ll be glad you did.

The river will drop considerably in the next 24 hours. The forecast shows flood stage ending at Natrona Lock and Dam before noon tomorrow.

p.s. Learn more about peregrine chicks’ development here:

10 April 2024

Peregrine news is quiet in early April while all the nests are incubating … or are they? I just did the math and Tarentum Bridge is going to hatch on or before today (see end of article). Here’s the news.

Cathedral of Learning, Univ of Pittsburgh: Yesterday I just happened to be on the roof deck of my apartment building at 6:24pm when I saw a peregrine burst off the Cathedral of Learning and head east over Fifth Avenue using territorial flappy flight. I could hear it kakking while a second peregrine was in the sky over South Craig Street circling up and up and up. The “flappy” peregrine circled up too and dove on the intruder, driving it to the east.

Yesterday’s motion detection photos indicate that the “flappy” peregrine was Carla. Both peregrines were watchful all day, then suddenly at 6:24pm Carla got mad and left the nest quickly, shouting to Ecco to take over incubation. I was very lucky to see the encounter in the air.

p.s. The falconcam is just fine but Ozolio’s stream is funky. You’ll sometimes see an old still shot, then spinning, then another still shot, then eventually the actual live stream. The National Aviary is working with Ozolio tech support to fix it.

Downtown Pittsburgh: On 28 March 2024 I stood near the Monongahela Incline on Mt Washington and used my scope to peer into the Third Avenue peregrine nest where I saw a peregrine incubating eggs.

East Liberty Presbyterian Church, Pittsburgh: On 29 March Adam Knoerzer reported that the nest is definitely within the blue circle in his photo below. “The female is always there and never on the exterior except when the male pops in for a shift change.” (I think this on the Highland Avenue side of the steeple.)

Eckert Street, Ohio River: As of 5 April Jeff Cieslak reports that a peregrine pair is near the Eckert Street nest site but they don’t appear to be nesting there. He says it’s the same female, probably a new male.

Sewickley Bridge, Ohio River: Jeff Cieslak reports: “On several visits during March, one or two falcons were fussing around under the bridge, near the far pier. On April 3, two were observed in what appeared to be a nest exchange on a beam near that area. This will be the third year that I’ve witnessed a breeding pair on this bridge, and I have never seen a fledgling.”

Monaca Railroad Bridge, Ohio River: For a while it looked as if the peregrines would nest but their attempt must have failed. eBird reports from the “Mouth of the Beaver River” hotspot in late March through 2 April indicate that both peregrines are visible simultaneously. Definitely not incubating.

Rt 40 Bridge, West Brownsville, Monongahela River: Fred Kachmarik and Jeff Cieslak both visited this bridge in mid to late March and saw a solo peregrine. Here’s Jeff’s photo from 23 March. Since this site was successful in the past, it looks promising for a family this year.

Every potential site is listed below …

and you’re probably wondering …

When will the eggs hatch? … How about TODAY? see below

The usual calculation is “34 days after incubation begins,” though in most cases we don’t know when it started. Of the four nests that seem to be incubating here’s a rough guess.

• Cathedral of Learning: Started around 3/19; Hatch approximately 22 April.
• Downtown Third Avenue: Your guess is as good as mine. We didn’t know they were incubating until 3/28 because we didn’t look.
• Sewickley Bridge: Saw a nest exchange on 4/3; Hatch on or before 7 May … probably before.
• Tarentum Bridge: Saw incubation 3/7; Hatch on or before TODAY! UPDATE: Dave Brooke got video today of the two chicks at Tarentum Bridge. They are more than a week old as of 10 April — possibly 9 days old!

(credits are in the captions)

1 April 2024

Carla and Ecco have completed nearly two weeks of incubation at the Pitt peregrine nest and have three more to go. As we watch them on the National Aviary falconcam it can be difficult to tell who’s on camera because their appearance is similar. Here are some tips for figuring out which bird is on the nest right now.

Nighttime incubation? It’s Carla except …

Ecco sometimes brings food before dawn so you may see him on the nest in the early morning while Carla eats.

Whenever you’re in doubt, use these tips.

Size: Carla is larger

Male peregrines are one-third smaller than females so size is the obvious way to tell the difference between the Pitt peregrines (see slideshow at top). However, Carla is not an enormous female and at close quarters on the falconcam with her back turned I have a hard time identifying her by size. The difference is obvious in this slideshow but not when Carla is alone on camera.

Plumage: Carla is Scalloped, Ecco is Striped

This spring in fresh breeding plumage Carla’s feathers have white tips that make her appearance look scalloped. Ecco’s feathers do not have long white tips so he looks vertically striped with fine black lines. Note that this difference works right now but feathers are dynamic and will not look the same in a few months.

Quiz! Test your skills

Practice recognizing size and plumage differences in this short video that compresses 60 hours into 1:41 minutes. At this speed the size differences between Carla and Ecco are obvious but you’ll have to look at one spot on the screen to notice plumage. Stare at one place and think “Scalloped or Striped?”

Do you have a favorite method for telling Carla and Ecco apart? Post your tip in the comments.

Meanwhile get more practice at the National Aviary Falconcam at Univ of Pittsburgh.

(photos and video from the National Aviary Falconcam at Univ of Pittsburgh)

24 March 2024

Incubation began last week at the Pitt peregrine nest. Carla and Ecco are now 6 or 7 days into The Big Sit.

To incubate their eggs and brood their chicks, birds open their warm feather coats by developing a brood patch for the breeding season. The brood patch is bare skin on their bellies that they place directly against the eggs to keep them warm. It has no feathers or down and lots of blood vessels close to the surface. When the bird is standing upright, surrounding feathers fall over the patch to cover it. If you had the bird in hand, as this bander holds a kestrel, blowing on the bird’s belly will move the surrounding feathers away so you can see the brood patch.

Both male and female peregrines have brood patches and both incubate the eggs. Instead of one big patch as on the kestrel, Birds of the World describes peregrines as: “Both sexes have paired lateral brood patches. Less well developed in male.”

To expose the brood patch and incubate the eggs, peregrines move the surrounding feathers out of the way by bobbing up-and-down and side-to-side. In this video Carla turns the eggs with her feet, then bobs to open her brood patch before she settles on the eggs.

Female peregrines incubate all night (with this interesting exception) but the amount of time the male incubates during the day depends on the couple’s preferences.

Some males love incubation duty, others not so much. Birds of the World sites several studies (paraphrased): “Based on studies in interior Alaska, males incubated about 33% of time. A study by Nelson suggested that for the Pacific Northwest male, incubation was 30–50% of the time. An extreme case in New Mexico was a male incubating as much as 87% of daylight period.”

Ecco loves to incubate so Carla and Ecco are still working it out. In this 20 March video Carla wails off camera “I want something to change!” Yup. She wants to incubate. Ecco eventually gets the message.

Peregrine eggs hatch 33-35 days after incubation begins but when did it start at the Cathedral of Learning?

Typically incubation starts after the next-to-last egg is laid — that would be Egg #3 on 19 March at 2am — but it looks like it may have begun on the 18th before that egg was laid.

Two Day-in-a-Minute videos illustrate the difference between incubating and not. This one on 17 March shows that the two eggs are often exposed.

On 19 March there are 3 eggs and incubation has definitely begun. Notice that Ecco is on the nest more than half the time on that day –> 54%. He’s the smaller bird and is present 390 minutes out of 720 mins in the video. No wonder Carla wailed at him on the 20th!

So incubation began on either the 18th or 19th of March. It is hard to tell about the 18th because it was cold that day (28°F to 36°F) and Carla and Ecco may have covered the eggs to protect them from freezing without opening their brood patches(*).

We’ll never know for sure whether the brood patch was open because we can’t see under the bird.

Carla and Ecco have 27 to 30 days to go for The Big Sit at Pitt. Watch them on the National Aviary Falconcam at Univ of Pittsburgh.

(photos and videos from the National Aviary Falconcam at Univ of Pittsburgh)

(*) EXPLAINING DELAYED INCUBATION: Some species, such as bald eagles, incubate immediately as soon as an egg is laid. Within these clutches the chicks hatch days apart from each other. Others species, such as peregrine falcons and ducks, want the clutch to hatch all at once so they delay incubation until the clutch is (nearly) complete. During freezing weather the eggs must be protected from freezing. Covering them without opening the brood patch is one way to regulate the start of incubation.

21 March 2024

Carla laid her fourth egg at the Cathedral of Learning at 10:25a this morning, 56.4 hours after Egg#3. Most of us didn’t realize it happened. Thanks to Laurie Kotchey’s sharp eyes and her comment on my blog, I knew to start looking for Egg#4 when I got home at 11:30a.

The video below shows the egg-laying moment, sped up to double-time, but you won’t see the egg itself because Carla is facing the camera. Instead, watch her behavior. She eventually stands tall, opens her beak and points it upward. Wait for the moment when she bows down and raises her tail as she lays the egg.

I believe this is Carla’s last egg for the year because she has already started incubation. More about incubation in an upcoming article.

Watch the Pitt peregrines on the National Aviary Falconcam at Univ of Pittsburgh.

(photo and video from the National Aviary Falconcam at Univ of Pittsburgh)

20 March 2024

Back in early February, Malcolm Kurtz stopped by East Liberty Presbyterian Church to photograph the resident peregrines. He found them carrying prey, perching on the steeple and hanging out together.

Malcolm first noticed the birds in December when “[he] saw an adult perched on the steeple from an overlook on Chatham’s main campus.” Good thing he followed up on it. The red aircraft hazard lights, which don’t look red from a distance, had fooled me so often that I stopped looking for raptors on the steeple. Malcolm’s photos show that a perched peregrine is about the same size as the lights but the bird is hard to see. If you’re near the steeple look carefully. How do peregrines manage to match every building they perch on?

While on site on 8 February Malcolm saw the female (at right) bring prey back to the church and eat it while the male looked on (at left). Notice that she is peachy compared to him.

Meanwhile Adam Knoerzer checks on the peregrines every day and has noticed they’ve changed their area of focus. On 14 March he recorded the male flying in with prey and, later, the pair flying together.

The peregrines have been spending a lot more time on the east face of the steeple.

This is the side of the steeple facing Highland Avenue. Around a month ago, I primarily spotted them on the opposite side of the steeple and south face, but they have tended to perch over on this face in the past week or two.

— email from Adam Knoerzer, 14 March 2024

• Green = floodlight where female likes to perch.
• Red = plucking perch where male prepares food for female.
• Blue = possible peregrine nest zone. Shows sticks leftover from old red-tailed hawk nest. Female often perches here at sundown. In first video below, male drops off food at this location.

Their change of venue probably reflects the lack of substrate anywhere else on the structure. This location is probably the only place that has an obstruction to prevent their eggs from rolling off the building.

If you want to see the East Liberty Presbyterian peregrines look from the Highland Avenue side first.

(credits are in the captions)

19 March 2024

This morning Carla laid her third egg of the 2024 season at 2:01am. Because her nest is visible on a timestamped camera, I can tell you she laid the 3rd egg 52.87 hours after Egg#2. (Egg#2 was 53.14 hours after Egg#1.)

Here’s a video of the egg-laying moment, sped up to double-time, which happens to make it obvious.

By 6:29am Carla had been off the eggs for 90 minutes (standing up). That’s a very long time to be off the eggs if she had already started incubation because they would cool dangerously in this morning’s freezing weather.

Peregrine incubation begins when the female has laid her next-to-last egg but it is always hard to tell when it truly starts if the weather is cold because the adults cover the eggs to keep them from freezing. When incubation truly begins, the parent exposes the brood patch and lays its bare skin against the eggs. Peregrines can vary how much skin is exposed thus delaying the actual start of incubation until the clutch is nearly complete.

Learn more about the parents’ roles in incubation here. By the way, the bird covering the eggs on recent mornings has been Ecco.

Watch the Pitt peregrines on the National Aviary Falconcam at Univ of Pittsburgh.

p.s. Happy Spring Equinox tonight: 19 March 2024 at 11:06pm.

(photos and video from the National Aviary Falconcam at Univ of Pittsburgh)

17 March 2024

Carla laid her second egg last night at the Pitt peregrine nest, 16 March 2024 at 9:08pm.

In this video clip from the National Aviary falconcam we see the actual laying occurred quietly at timestamp 21:08:38. (This is 53.14 hours after her previous egg.)

Carla then raised her tail and remained in a standing position as she waited for the new egg to dry. Though the eggs are actually reddish in daylight, they look white under infrared night light.

After the egg dried Carla roosted on the green perch in front of the nest.

Mother peregrines are the ones who stay at the nest overnight with eggs and chicks while their mates roost nearby. Ecco was apparently roosting within earshot but not very close. I believe he knew she had laid a second egg; he probably watched (off camera) when she laid it.

Carla was still asleep on the perch when it rained at 4:00am. When Ecco woke up at 4:30am he started to wail. Wailing means “I want something to change.” Perhaps Ecco wanted Carla to cover the eggs or maybe he meant, “I want to change places with you.”

Carla woke up and responded with unusual squeaky chirps. She jumped to the nestbox roof and Ecco arrived to cover the eggs. Listen for his voice and the sound of robins singing in the dark at the beginning of this video.

An overnight nest exchange is very unusual but I’ve seen it once before. When Dori was a new mother at the Gulf Tower in 2010, Louie took over incubation in the middle of the night a couple of times (*). Louie had experience raising a family and Dori did not. Perhaps he was getting the eggs through a critical period, waiting until he felt confident that Dori had caught on.

Peregrines are quick studies at being parents but it’s always nice when one of them already knows what’s going on, as Ecco does.

Watch Carla and Ecco as their family grows at the National Aviary Falconcam at Univ of Pittsburgh.

(*)The nighttime nest exchanges at Gulf Tower in 2010 are described in these vintage blogs.

(credits are in the captions)