I observe osprey development every spring/summer, as there's a nest adjacent to my house, and they are devoted to their parental jobs; no way would they 'shrug off' such a loss.

Thank you for caring.

(And I've been told that we should not anthropomorphize animals, because they really hate that!)

I'm sure the Robins were grieving in their own way. The loss of offspring is traumatic.

Yeah, that would make me misty eyed.

We had to bury another fawn last week. The does sail over our fencing, but the babies cannot.

Its a hard world for little things.

the adult birds probably knew you were trying to help. The babies did not feel mental anguish or physical pain.
The parents will grieve, but they are more resilient than humans and new life will come to them.
I once tried to get a pigeon who was downed off a busy sidewalk. Her companion was hovering and yes, helped me get her up the stairs out of the way. I went to tell my roommate and when we got to the stairs the companion had its wing around the downed bird, both rested on a stair. My roommate put his jacket over them.
In the morning both were gone.
I know the companion knew what I was trying to do and pitched in. Our common mission and urgency made us act in perfect cooperation.
We are interconnected. Other species recognize our help.
Sometimes, even with wild animals, we can have a moment of that “communication” which seems to defy what we thought we knew. It is not always a projection.
You had tremendous courage in showing your respect and compassion.
You were the cavalry today and though you could not save the babies, you made the grownup robins feel not so alone in the big and often threatening world they live in.

That is, their natural process of mating and reproduction this time of year. Grieve? We don't have a way of knowing for sure, but one thing's for certain is their emotional and mental processes are totally different from ours, theirs being more driven by instinct. I think we know that many animals experience fear, or at least adrenal reactions like us.

I ran over a nest of baby rabbits with a riding mower in tall grass years ago and have never forgotten it. Demonstrates the emotional complexity and sensitivity, and long-term memory of us humans.

I love robins. They are a gentle sort and are the first to sing in the morning before daybreak. However, they ain't the smartest of the lot because they build nests in the worst damn places (like on top of fence posts).

KY............

A hawk flew through my yard and grabbed a young swallow that had just learned to fly. The mother's scream was the saddest thing I have ever heard.
They do go on. That is what I learned from the birds - no matter what they go on.

There was a Canadian goose couple that nested outside our window one year. A predator got the eggs in the night and destroyed the nest. The female spent the next few weeks staring at the site. She rarely moved and appeared to stop eating and drinking. Two weeks later she died

Her spouse wandered around the neighborhood alone all that summer and avoided the flock.

It may not have been what we describe as grief, but the event definitely impacted their lives.

My parents had spent many hours teaching this African Gray parrot to talk.

And I also remember coming upon a fox in the road who would not leave the body of another fox who had been hit by a car. My boyfriend stopped our car and moved the body to the side of the road, so that the surviving fox could stay with it in safety.

I have no doubt that animals experience grief. Elephants will often carry tusks or bones from dead members of their herd. Other species, as well as elephants, will carry their dead infants in ways that they would not carry their living young. Our unwillingness to interpret their actions as grief says more about our own sense of exceptionalism than about animal behavior. Maybe we are afraid to consider a world where animals' feelings are as profound as our own because if we did, the horrors we inflict via factory farming and habitat destruction would be too awful to contemplate.

https://www.pbs.org/wgbh/nova/article/animal-grief/

Thank you for your kind heart. It is hard to acknowledge animal grief. Empathy hurts. But we need more people like you. And so do robins and other sentient beings.

I don't want to think about it too much, or I'll cry.

the apartment above me has a wooden balcony that covers my front stoop. Birds have been building their nest in an opening underneath it, and like clockwork, I go out on my porch in the spring and find a dead baby bird on the concrete below it. Just breaks my heart, but I don't know what to do about it. The baby falls about 10 feet or so. This is the first year out of 5 that it hasn't happened. I'm hoping the parents got a clue.

At least some of us in this world have some heart and compassion for wild creatures. I think it says a lot about the kind of man you are.

I don't know if they have "feelings", but more instinct. The adult Robins instinctively knew they had to care for the babies until they were able to leave the nest on their own. The fallen nest interrupted their instinctive behavior. I'm sure once they realized there were no more babies to care for, they simply went on with their normal lives with no regrets or sorrow.

My only rule is: not in the house.
Creatures in the house are not allowed.
I will take the lizards outside and let them go (cats).