Mother red-crow (coucal) bird feeds chicks with their sibling's meats.

[Reporter]

The mother does feed the three chicks with various kinds of
kills.

But at one point, she takes one of them out and brings back its
body pieces to feed the other two.

From 4:54 min. to the end.

https://www.youtube.com/watch?v=0mMr4yQNGWk

I can see that the few weeks of feeding mother birds
have to fetch to feed their youngs can be difficult. This
is also something mother birds are impatient about,
because they can fly and just want to be wild and free.

So,  killing one to lessen the responsibility is a good
approach for them.

I've seen videos of cranes and herons do that to
their chicks, too--dropping one outside the nest
to kill off.

Cuckoos don't even feed their chicks; they just
lay eggs in other birds' nests and fly off
to enjoy life.

It is a tough world for the wild out there.

[Believe_N_Me]

You can already guess what I have to say about this.

[Reporter]

Ain't no tellin' birds what to do, BNM.

[P90xbox]

not sure if this is natural to them...but wild animals will adapt to their environment and surroundings.. .this probably happens when their habitats, or the eco system is no longer natural to them...they have competition to find food, or their food source is depleting...th e mother birds have to resort to a tough decision.....o h trust me reporter, if she wanted to be free and no responsibility, she'd called the snake....lols

[Hung_Low]

same phenomenon as some bird parents encourage and watched the baby chicks kill each others - survival of the fittest.

Can we implement the same thing... you know, stopping climate change.

[Reporter]

This mother crane throws one of her babies off the nest, too.

https://www.facebook.com/reel/569252608497410

[VillainousHero]

Real hard life.  Sometimes there's just not enough food for everyone.

[Reporter]

Real hard life.  Sometimes there's just not enough food for everyone.

Plus,  motherly love can only go so far...

[Reporter]

I have been thinking over this issue--why these mother birds kill their babies this way.

Some may say it's a natural bird ritual or rite like a sacrifice to a deity or something
that naturally happens. 

But, as I think more and more about it, I don't see that to be the case. I think my
former little girl was right that there's just too much to do in feeding the babies.

It is only when mother birds have to work hard on their own that they get rid of the
babies. This is to reduce the efforts needed to sustain them. It's just a lot of hard work
to fetch at places when one has no set storage of the resources. Birds don't have a warehouse
to go to; they don't have a freezer to keep foods in. Etc.

Then, if we look at the domesticated animals like the chickens and ducks around farmers'
barns, they don't kill their babies. That's because mothers don't have to do all the work. Chicks
and ducklings, too, start finding their own foods in waters and by scratching the ground
with their mothers. All their mothers do is enjoy taking them around.

So, it is not a religious sacrifice but one of both food shortage and exhaustion of the mother
birds that make these mother birds kill off their youngs.

[Reporter]

This mother crane bird eats her chick.

https://www.youtube.com/watch?v=EozbvwncH_c