Category Archives: Nesting & Courtship

Tenants Add Mud to the Apartment

screenshot of banner: Gwyllt Hollow – Sitting Room Nuthatches

19 Friday 2024

Last Friday we watched a Eurasian nuthatch (Sitta europaea) vigorously remove a decoration from his beautifully furnished nestbox in South Wales. Apparently the Tenant Didn’t Like the Decorations (blue box).

Nuthatch removes a decoration from the nestbox (screenshot from @katemacrae WildlifeKate on X)

Since then the pair has been remodeling the apartment to their liking. They’ve added plenty of leaves and are now applying plaster (mud!) to the interior. Are they covering the decorations they don’t like? Or just filling in the gaps?

The nuthatches now have their own Live Stream at Gwyllt Hollow – Sitting Room Nuthatches. Follow WildlifeKate @katemacrae on X for updates.

Who’s Making That Metal Drumming Noise?

Northern flicker, male (photo from Wikimedia Commons)

18 April 2024

In case you haven’t noticed, northern flickers (Colaptes auratus) are loud right now.

The Northern Flicker is very vocal in spring during which its long call (kick, kick, kick, kick, kick) and drumming may be heard from more than a kilometer away [0.62 mile]. Homeowners sometimes express annoyance at individuals who take to hammering on metal chimneys and gates early in the morning, but fortunately this territorial advertisement only lasts for a few weeks in spring. 

Birds of the World, Northern Flicker vocalizations

Both sexes of flickers make a “jungle” call and drum loudly to attract a mate and establish territory. When drumming on wood they sound like this.

LOUD is important and city flickers have figured out that hammering on metal is louder than wood.

They hammer on streetlights. (This one stopped drumming for his photograph).

Northern flicker on streetlight, waiting to hammer (photo from Wikimedia Commons)

They hammer on the metal covers on electric poles. (Hey, be careful!)

Northern flicker hammering metal on electric pole (photo from Wikimedia Commons)

They hammered on the metal hoods of these old ballpark lights every spring. The lights were replaced at Magee Field in 2018. I never got a photo of the flickers on the floodlights but here’s one of a red-tailed hawk.

Old ballfield lights at Magee Field, Pittsburgh, with red-tailed hawk, July 2018 (photo by Kate St. John)

Flickers can be annoying when heard across the street, and worse than annoying when closer to home.

Who’s making that drumming noise? A northern flicker.

(credits are in the captions)

Pitt Peregrine Alumni is Nesting at Sewickley Bridge

Peregrine at Sewickley Bridge, 16 May 2023 (photo by Jeff Cieslak)

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?

Banded male peregrine at Sewickley Bridge, 6 June 2023 (photo by Jeff Cieslak)

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.

Peregrine nest exchange at Sewickley Bridge, 25 March 2024 (photo by Jeff Cieslak)

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
Banded male peregrine at Sewickley Bridge (Black/green, 05/S) on 4 Feb 2024 (photo by Jeff Cieslak)

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.

Neville Island I-79 Bridge wrapped for construction, 2023 (photo embedded from Beaver County Times)

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)

Tarentum Peregrine Chicks are Growing Fast

Tarentum Bridge peregrines have two chicks, 11 April 2024 (photo by Dave Brooke)

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.

video embedded from Dave Brooke on YouTube

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.

Flood stage on Allegheny River at Natrona Lock and Dam, 13 April 2024 at 6am

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:

Peregrine Update, Southwest PA, 10 April

Carla at Pitt peregrine nest, about to incubate, 9 April 2024 8:32am (photo from the National Aviary falconcam at Univ of Pittsburgh)

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.

Third Ave peregrine nest Downtown as seen via scope from Mt Washington, 28 March 2024 (photo by Kate St. John)

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.)

East Liberty Presby Church steeple. Look in the blue circle for peregrines to/from the nest (photo by Adam Knoerzer)

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.

Peregrines in flight near Eckert Street, Pittsburgh, 12 March 2024 (photo by Jeff Cieslak)

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.”

Peregrine pair at nest hole on Sewickley Bridge, 25 March 2024 (photo by Jeff Cieslak)

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.

Railroad bridge over the Ohio River from Monaca to Beaver (photo by Kate St.John)
Railroad bridge over the Ohio River from Monaca to Beaver (photo by Kate St.John)

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.

Peregrine at Rt 40 Bridge, West Brownsville, PA, 23 March 2024 (photo by Jeff Cieslak)

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)

Have You Ever Seen a Baby Pigeon?

Feral pigeon walking (photo from Wikimedia Commons)

3 April 2024

City folks often see pigeons but all the birds are adults. Have you ever seen a baby pigeon?

Rock pigeons nest on cliffs in the wild or in nooks on high buildings or bridges in feral settings. This puts their nests high above our field of view and, since the young won’t leave the nest until they can fly, they don’t look like babies anymore when we finally see them. They look like their parents.

Every once in a while a pair of pigeons will choose a balcony or window ledge where the resident can see the nest. This happened for @LostInTheWildCanada who documented the pigeon family on YouTube.

video embedded from Lost in the Wild Canada on YouTube

Who knew that rock pigeon nestlings are covered in yellow-orange down? Who knew their eyes didn’t open for a week? Who knew they were so … ugly?

Rock pigeon nestlings, Day One and approximately Day Six (photos from Wikimedia Commons)

Now you know.

(credits are in the captions)

Who’s On the Pitt Peregrine Nest?

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

Carla incubating at night, 27 March 2024, 10:58pm

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

Ecco on the nest before dawn, 29 March 2024, 7:15am

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?”

Pitt peregrine nest 60 hours of incubation compressed to 1:41 minutes, March 28-30 (video from the National Aviary falconcam at Univ of Pittsburgh)

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)

Pigeons Conspicuously Court in Public

Rock pigeon male (on right) struts and coos for his mate (photo from Wikimedia Commons)

28 March 2024

Peregrines hang out where their food is plentiful so they’re often in places with lots of pigeons. Watching peregrines, as I often do, means waiting (bored) for them to choose the perfect moment to catch a bird. Inevitably I watch pigeons while I wait for peregrines so I’ve seen a lot of pigeon courtship.

Most birds have a breeding season for a few months per year in spring and summer but rock pigeons, like humans, breed over and over all year long if there’s enough food to sustain their families. You can tell when they’re starting a new family because they court conspicuously.

Birds of the World’s rock pigeon account, quoted in the list below, explains the steps of courtship that escalate to the moment of copulation.

  • [Courtship] Begins with bowing and cooing, in which male stands tall, inflates crop, fans tail, struts in circle, bows head and neck while giving display coo. This is repeated many times while circling and moving around the female. 

  • Hetero-preening (“nibbling”) follows, male first, female later.
Rock pigeons “nibbling” as part of courtship (photo from Wikimedia Commons)
  • [Billing:] Female ultimately solicits feeding, male appears to regurgitate seed or liquid. Female may repeat …
Courtship billing (after cooing) in which male appears to be feeding female (photo from Wikimedia Commons)
  • … followed by a crouch with wings half raised. Male then mounts, balances with flapping wings while vents are opposed 1–2 seconds for sperm transfer.
Rock pigeons mating (photo from Wikimedia Commons)

After mating the male may do a post copulatory display. Sometimes they fly together.

  • Post-copulatory display includes a few steps while standing tall, and often a display flight, usually by the male, in which wings are clapped together on an exaggerated upstroke for 3–5 wingbeats. Bird flies out to another perch, 40–80 m distant, clapping wings at least once and gliding with wings in a “V” between bouts of clapping
Two rock pigeons flying (photo from Shutterstock)
Two rock pigeons flying (photo from Shutterstock)

While you’re observing pigeon courtship there’s one more thing to notice. The male and female do not have the same plumage patterns because they choose mates that don’t look like themselves.

Peregrine Incubation: The Big Sit at Pitt

Carla tells Ecco it’s her turn to incubate, 20 March 2024 (photo 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.

Brood patch on a female kestrel (photo by Jared B. Clarke, Birding Saskatchewan blog)

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.

Carla prepares to incubate, 20 March 2024 (video from the National Aviary falconcam at Univ of Pittsburgh)

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.

Carla tells Ecco she wants to incubate, 20 March 2024 (video from the National Aviary falconcam at Univ of Pittsburgh)

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.

Day-in-a-Minute, 17 March 2024

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!

Day-in-a-Minute, 19 March 2024

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.

4th Egg Laid Today at Pitt Peregrine Nest

Ecco and Carla touch beaks over their 4 eggs at the Cathedral of Learning peregrine nest (photo from the National Aviary Falconcam at Univ of Pittsburgh)

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.

Carla lays Egg#4, 21 Mar 2024, 10:25am (video from the National Aviary Falconcam at Univ of Pittsburgh)

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)