Pigeon Update!

I am afraid it is a sad Sunday here at Pigeon Central.
For those of you perhaps just tuning in, I described in a blog (May 30th, entitled “Pigeon Central”) how that this year I have two pigeon families nesting on my balcony. I have been looking forward to this season’s hatchlings, and as I described in the blog, due to certain ads that the pigeons had placed in a periodical called Nesters Monthly, I was even thinking that perhaps a few more families would have moved in by now.
But I went out there to check on them this morning.
The news is not good.
The eggs are gone.
All three eggs that were there, are gone.
At first, I couldn’t believe my eyes. So I bent down to have a closer look and then a pigeon fluttered out from behind this old wooden chair in the corner. And instead of flying away (as they usually do when encountering me), it just walked over to the one planter which had been its nest, and looked up at me, blinking. (I am not making any of this up). I could tell it was furious.
And scared. But more furious than scared, because if it was more scared than furious, it would have simply flown away.
But no.
It had business with me. It was now obvious to me that it had been waiting behind that wooden chair for a moment like this! It fixed me with that eye, and said:
“WHERE...
IS...
THE...
EGG?”

“I swear to you, I have no idea, I haven’t even been out he...”

“NO.
SERIOUSLY.
WHERE
IS
IT?”

I felt so bad. Honestly.
I have nothing to say to this bird.
I did not take its egg.
Nor did I touch the other two. The other eggs, in the big clay pot.
But all three are gone. And as I turned away from this mad-as-a-hen pigeon-mother, I discovered one of the eggs there on the concrete, quite a ways from either nesting area. Smashed, no yoke or embyonic bird in it even... the sun must have dried either thing away. Or something (eegads!) ate the contents.
This is a mystery to me. It really is.
The Case of The Disappearing Balcony Eggs.
No one else (human) that I know of has had access to my balcony. My cat has not been out there. Not even once.
So, my next step is to ask the superintendent about it. I know that recently, just a few days ago, workers were in my apartment while I was at work. They were installing a condensate pipe in the air conditioner. But they would have had no reason to be out on my balcony.
Is there such a thing as other birds that would fly up there and steal and/or eat these eggs?
Seriously, I do not know this.
What do they do? Carry the eggs away in some sort of bird-backpack? I mean, but for the one omellette there.... not even a shell fragment from the other two is left behind.
No evidence.
No fingerprints.
No footprints.

Just the ominous twirling sound of my neighbor’s Wal Mart Bird-B-Gone pinwheels on the next balcony rail. Twirling like it's the end of the world.
And a mad mad, mournful pigeon looking up at me with everything in its beady eyes but tears.