A question about bird behavior.

[Dinner]

So in my backyard, on top of one of the rear porch lights a pair of doves have made a nest. We'd seen that the female had laid two eggs in the nest though we made very certain not to touch or disturb the nest in any way. Today, as I was washing down the back patio I noticed the female dove had pushed one of the eggs out of the nest. I am not sure why. Does anyone have any ideas?

Picture of dove sitting on nest after it had pushed one egg out. (Picture needs to be rotated 90 degrees counter clockwise.)

https://ibb.co/MMD84yM

[Dinner]

I did find this online.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.startribune.com/dove-dumped-egg-from-nest/500936272/&ved=2ahUKEwiG8M2IiK7vAhVOsZ4KHXbsBWcQFjAAegQIARAC&usg=AOvVaw1dqpBxmj5Ik1l4MGa6aR0H&cshid=1615665800979

[SlowwHand]

Probably detected a genetic weakness.

[EPW]

It's an offering. Accept by sitting on the egg, then flapping your arms and screeching. Then the bird will be at your command.

[ZEE]

Oerdin can do an ancient pagan belly-slap dance. Since Oerdin's belly is so gigantic, birds from miles around will hear it!

[-Jrabbit]

The interloper theory you linked to sounds viable, and I did find a bird forum post stating that doves can sense whether there's life in the egg. But I have no personal knowledge to offer.

Semi-related: We have had a robin's nest in our porchlight each of the last 2 years. It's been pretty cool.

[Egbert]

Birds (or at least some species) stop sitting on their eggs if those eggs are not going to hatch. I have no idea how the bird decides whether or not eggs will not hatch. This seems a very likely reason for your dove dumping an egg.

[BeBMan]

The early bird catches the worm.

[BeBMan]

As for birds pushing out eggs, don't get me started on the cuckoo's constant malpractice...