Incubation began three and a half weeks ago at the Cathedral of Learning peregrine nest. During the day Morela and Ecco take turns every one to six hours.
Because peregrines delay incubation until the clutch is almost complete, nearly all the eggs will hatch on the same day. We humans predict Hatch Day will be between 20 to 26 April. My calculation is on the late end of that spectrum (here).
The peregrines know when Hatch Day is coming because they can hear the chicks inside the eggs. As hatching approaches, Ecco will spend less time on the eggs and Morela will take over.
Our first visual indication will be a pip, shown here in 2013. The chick will emerge in about 72 hours.
How can you tell if an egg has hatched while Morela is completely covering the eggs? Look for a discarded half eggshell away from the scrape, shown here in 2013.
At the Cathedral of Learning peregrine nest Morela and Ecco have been incubating four eggs all night, all day, and in all kinds of weather since 23-24 March. Incubation is boring except for the weather events.
Recurring heavy snow showers moved through in Pittsburgh on April Fools’ Day (1 April). Morela kept dry under the nestbox roof until the wind blew the snow at her.
Here’s her reaction to an intense snow shower. Was she scowling?
Yesterday, 4 April, it was so hot that Morela was able to expose the eggs for five minutes while she panted and sunbathed.
Morela incubates all night. Ecco helps out by arriving every morning before dawn. On 31 March he had a message for her. Was he telling her where he stored her breakfast? Was he saying “No need to hurry back” ? Who knows.
Every day is the same. There’s always a bird on the nest. The pair switches off several times a day.
Allegheny River: Rt 422 Graff Bridge Kittanning, Armstrong County
Cathedral of Learning, University of Pittsburgh:
Morela laid her fourth egg yesterday at 3:38pm (real time, 3:42pm camera time). As you can see from the 24 March timelapse video, she and Ecco rarely step away from the eggs. Morela stood up at 3:38pm to lay the fourth egg then settled down again as soon as it dried.
Best viewing of the Third Avenue nest site is from Grandview Avenue on Mt Washington next to the Monongahela Incline. On 20 March Jeff photographed a peregrine perched inside the nook. At that point it appeared they were choosing this location, not Gulf Tower.
Yesterday afternoon, 24 March, I confirmed nesting. When I set up my scope I immediately saw a peregrine in the back left corner standing in the about-to-lay-an-egg posture. As I waited and watched she laid at egg at 3:23pm, paused, raised her foot, then carefully stepped around it and stood waiting for it to dry. Dori laid her egg just 15 minutes before Morela laid hers.
Jeff Cieslaks’ photo insets from Tuesday at 5:43p show an incubating peregrine where the egg was laid … so maybe I saw Dori laying her last egg.
Monongahela Watershed: Westinghouse Bridge
Dana Nesiti photographed the Westinghouse Bridge peregrines mating on 21 March 2021. They are certainly planning to nest!
Male peregrine flies toward female, Westinghouse Bridge, 21 March 2021 (photo by Dana Nesiti)
Male peregrine lands on female
Female watches as male flies away
Monongahela River, Speers Railroad Bridge:
The Speers Railroad Bridge peregrines have been identified thanks to photos by Joe Ciferno and Dana Nesiti. Both birds are banded:
Female – 07/BS Black/Green, banded on 5/18/2017 on the Commodore Barry bridge over the Delaware river in Chester, Delaware County, PA.
Male – 68/AC Black/Green, banded on 5/23/2012 at the Cathedral of Learning University of Pittsburgh Allegheny County, PA.
Ohio River, McKees Rocks Bridge: No news. Observers needed!
Ohio River, Neville Island I-79 Bridge: No peregrines due to construction. The underside of the bridge is completely covered. No nest access.
Ohio River, Ambridge Bridge: Peregrines are present throughout the year. Karen Lang has recently seen a single bird, apparently the male, perched on the bridge — Sunday 22 March at 4pm and Wednesday 24 March at noon. Perhaps this pair is incubating.
Ohio River, Monaca Railroad Bridge:
Jeff Cieslak was in Monaca on 21 March and photographed the peregrines perching and flying around the superstructure. Sometimes they are hard to see.
Allegheny River, 62nd Street Bridge to Aspinwall Railroad Bridge: No peregrines. One was present in January and February but no sightings since then.
Allegheny River, Tarentum Bridge:
Dave Brooke’s 16 March photo shows a peregrine very low in the nestbox. (Can you see her?) It appears this pair is already incubating.
Allegheny River, Rt 422 Graff Bridge, Kittanning:
On 14 March I walked under the Graff Bridge at Manorville and immediately saw a peregrine perched on the upriver side. Peregrines are present. Are they nesting?
Observers needed! Visit these sites and tell me what you see.
(photos by Kate St. John, National Aviary falconcam at Cathedral of Learning, Jeff Cieslak, Dana Nesiti, Joe Ciferno, Dave Brooke)
Meanwhile at the Cathedral of Learning peregrine nest, 3.5 miles away, Morela laid her third egg yesterday morning. Peregrines typically lay 3-5 eggs so Morela may lay more. We won’t know until we see it.
The peregrine timelapse video below shows the adults may be incubating, though I wonder about Morela’s 90 minutes on the perch from 4p – 5:30p. If incubating has begun the hatch date will be a month from now, approximately April 20-24.
Interestingly, though the peregrines started nesting a month later than the eagles they will more than catch up in the end. The Pitt peregrine nestlings will fly at least a week before the Hays eaglets.
The Hays eagles schedule this year is …
First eagle egg laid = 12 February 2021
First eagle egg hatched, first chick = 23 March 2021
First flight expected = guessing June 11 – 20
The Pitt peregrines’ schedule is …
First peregrine egg = 17 March 2021
First peregrine hatch (most will hatch on the same day) = approximately 20-25 April.
First flight expected = guessing 30 May to 4 June.
Soon the Hays bald eagle nest will have active fluffy chicks while the Pitt peregrines will embark on The Big Sit. For the next month it will be more interesting to watch the eagles than the peregrines.
After Morela laid her first egg on St. Patrick’s Day many of you had questions about incubation. Here are some answers.
Why aren’t they sitting on the egg? Unlike bald eagles peregrines do not begin incubation until the female has laid her next-to-last egg. Only the female knows when that last egg will be. It hasn’t happened yet. Yesterday Ecco guarded instead of incubating. Click here for more details.
If incubation has not begun, why is Morela sitting on the egg? (photo at top)
Peregrines make sure their eggs stay dry and do not freeze. Yesterday was very rainy and very windy (raindrop on screenshot). Morela was keeping the egg dry.
How will we know when incubation has begun?
Incubation is the act of raising an egg’s internal temperature and keeping it there so that the embryo inside the egg develops into a baby bird (read more here). The temperature must remain elevated for the entire incubation period; otherwise the embryo dies.
Though it appears that incubation is just the act of laying one’s chest against an egg, the egg’s temperature will not rise if there are feathers between the egg and the parent’s skin. Feathers are excellent insulation so the parent has to have a bare patch of skin called a brood patch. It develops on brooding parents for the nesting season, lightly covered with feathers that the bird moves out of the way when brooding. Here’s what a brood patch looks like on another falcon, the American kestrel.
It is hard to tell if a bird is incubating by looking at a snapshot because you cannot see whether the bird exposed its brood patch. The best way to tell is by looking at the amount of time spent on the eggs. During incubation the adults spend about 98% of the day+night on eggs. This Day-in-a-Minute shows that Morela and Ecco are not spending much time on the egg.
Based on this evidence, incubation has not begun yet at the Cathedral of Learning nest.
In case you missed it at the Cathedral of Learning peregrine nest: Morela laid her first egg of 2021 on 17 March at 11:50am. (Time code on the streaming camera says 11:53a but that camera is 3-4 mins early.)
The timelapse video below gives an overview of the day’s activity: Morela, Ecco and the egg.
Details of egg laying: As the next video begins Morela was standing over the scrape but is restless. She paces and squats, then Ecco arrives to bow. He watches intently while she concentrates on laying the egg. After he leaves Morela pushes (raises tail), pants and lays the egg at 11:53:45am. Notice how she makes sure not to touch the egg while it’s wet. She moves to shelter it from the sun.
Father bird’s first visit: It is always interesting to watch the father’s first visit to the egg, especially since Ecco is a first-time dad. Ecco arrived at 1:20pm, chirped at the egg, turned it, dug the scrape deeper, and sheltered the egg from the sun. He is taking an active role in the egg’s welfare.
Do not worry that the parents are not “sitting” on the egg right now. Unlike bald eagles peregrines do not begin incubation until the female has laid her next-to-last egg — and only the female knows when that egg will be.
Until incubation begins both parents guard the eggs and shelter them but will not “sit” on them to raise their temperature. They will be nearby but maybe not seen on camera.
Morela will probably lay 3-5 eggs, one every other day. If her total is four, incubation may begin on or around 21 March. We’ll have to wait and see.
Check my Peregrine FAQs for information on incubation, hatching and peregrine behavior.