26 March 2025

When peregrines are incubating eggs there is rarely any action on the falconcam and it’s always brief, so chances are most of us weren’t watching when Carla and Ecco did this nest exchange yesterday morning. I missed it too, so here it is.

I’ve chosen to highlight this video, not because anything is unusual, but because it’s so nice to watch something other than a sleeping bird.

In fact the segment starts with Ecco sleeping, but he hears something I can’t hear (probably Carla) and raises his head to look around. We know she’s nearby when she wails.

What does she mean? From the Peregrine FAQs: Wailing means “I want something to change.”  The wail sounds awful but does not necessarily mean bad things are happening.  It really means “Things are not changing fast enough for my liking.” Read more about this call and others at Peregrine Vocalizations and What They Mean.

We can guess what Carla means in this context by watching Ecco. He knows she wants to trade places with him but won’t get up until she’s close by and ready to cover the eggs.

Carla comes closer and makes soft noises. Ecco leaves; Carla settles down to incubate.

Watch the Pitt peregrines on the National Aviary falconcam at the Cathedral of Learning. You might get lucky and see something interesting.

25 March 2025

Just when we’d thought Carla was done with egg laying Sara Showers saw 4 eggs at the nest this morning before dawn. We were surprised because peregrines usually lay an egg every other day. This one took twice as long and is 4 days after the prior egg.

It took a bit of searching the archives to find when it happened. Here is the moment at 4:34am.

Video of the few minutes before and after the egg appeared.

So my question about incubation is answered. It began, as it should, after the next-to-last egg.

25 March 2025

After Carla laid her last egg in the wee hours of 21 March at 2:07am and I saw her prepare to incubate the next morning at 5:40am, I declared on 22 March that incubation had begun. Was I right? I’m not so sure anymore.

I checked the falconcam timelapse videos and found that during the day of the 22nd Carla and Ecco both seemed to be incubating, but that night Carla spent an hour and a half off the eggs from 2:30am to 4:00am. You can see the gap in this timelapse video.

She also stood up for half an hour at 5:00am. What was she looking at?

On the 23rd incubation was more consistent. Carla and Ecco took almost no time off during nest exchanges and Carla slept on the scrape.

That night, 23-24 March, she stayed tight on the eggs especially while it rained. The raindrops look like snow in the infrared light.

So now I think incubation began on 23 March 2025.

Only the peregrines know for sure.

21 March 2025

UPDATE: I WAS WRONG! Carla laid her 3rd egg much earlier than I originally thought. It was before 2:07am on 21 March 2025.

I had expected Carla to lay her third egg last evening but it took a longer than expected. As early as 8pm she looked like she was ready to lay it (below), but it did not happen until this morning at 2:07 am (above).

At 5:40am I saw Carla corral the clutch, bob her body to expose her brood patch, and lay down with her back feathers standing up a bit, as shown in the video below. It looks to me like she’s begun incubation. (You can hear Ecco whining in the background.)

Hatch Day should be 33-35 days from now –> 23 to 25 April. In the meantime we’ll be watching The Big Sit on the falconcam for more than a month.

As I said earlier, there’s always a possibility that I’ve missed something and miscalculated the dates … and sure enough I’ve already had to make a correction.

p.s. Here’s a better look at the 3 eggs with Ecco standing next to them.