I suspected that. Raptor chicks can get very aggressive and sometimes KILL the other chicks. But Big Red, the mother, is very strict.

This is a photo taken from the roof of the building across from the nest, by a Cornell person. The nearly fledging chicks last season got out of hand, and Big Red, the mother, came at them with a show of dominance... It is a very revealing photo of parental bird supervision. Big Red does not put up with anything naughty from her chicks, (or mate).

wow, that's an incredible photo.
When the largest one ( I'm guessing first hatched F1) was attacking the others BR was keeping a very close eye on them and started feeding the little ones. The largest one was very strong in comparison and could keep their head up and seemed way more developed than the other two.
All very interesting. I'm not so fond of feeding times as it's all a bit gross early in the morning
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but feeding time allows a lot of their inate behaviours to be seen.

The chicks are very cute today. The afternoon feeding was very polite and civilized.
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They certainly have grown in a month.
I hadn't checked on them in a week or so and their feathers are totally different. Can't wait until they start flying.

Oh, Wow.... big guys now!
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F3 ready to fledge this minute.
Well, they're on the ledge. Might take more than a minute
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other two must have gone already. I don't know
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Edited to add: Found the other two once they changed the camera angle.

They sit on the ledge for several days if I recall...

But fledging already!! I've tried not to get too involved this year, as last year I regretted it. It is a weakness of mine I have to control and master.
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My son just called, he found a fledgling sparrow at a friend's house and instead of putting it where the parents can feed it, he brought it home. So I had a go round with him...to take it back etc. Sometimes his lack of common sense gets to me. He has watched us put fledglings back many times.... sheeesh. The poor baby is weak from hunger and may not last the night. Or it is ill anyway and meant to die. tough decisions. He cannot feed it every 2 hrs as it needs if he keeps it.
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Oh dear. Must have thought he was helping somehow.
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They won't fledge now, it's too late I imagine.
One of them (reading their chat they thought F3) was sitting there on the edge of the ledge for ages.

[mrsD, Sully - Birder on the ground - swerved apparently to stop from hitting a deer on the road and injured with broken nose]

Oh, that is bad news about Sully...Those birders on the ground work so hard for the process of tracking the birds, etc. I hope she will be alright.

My son can be so clueless...He has always been like that. Doesn't pay attention to details/empathy --- The ADHD monster still lives within him and shows up at times like this.

The most interesting fledging event we have had here lately was Weezie getting a robin, which provoked a major alarm of all the birds in our area. They became an army and chased her up from the creek and she came to me to save her! There were jays, robins, chickadees, sparrows, Cardinals, and others I couldn't see, but the commotion was considerable. I got the robin away, put Weez on the screened porch and put the robin where the parents could see and hear him. Fledging can be a very difficult, dangerous and deadly time for birds. Birds that are not 100% normal don't survive the fledge at all.