Not eggs, but prey. They use this movement to break its bones and kill it.
It's a siriema if I'm not mistaken. There are a bunch of them in the country side of where I live (Brazilian Cerrado). They are absolutely fantastic animals
This is a bird called the Sereima, and what you are seeing isn't random behavior: it's how they hunt. They chase rodents and lizards down, grab them with their beaks, then slam their prey down onto rocks repeatedly until they stop moving.
A surprisingly wide range of animals will engage in play behavior
Bumblebees have been shown to love having small beads around for them to roll around and on
Edit: sheer amount of people replying who can't just let the silly birb have fun. Guess what, dogs and cats derive play behaviors from predation too, doesn't mean that play ain't play.
I think you're right, but i also remember learnning that some birds have learned to break nuts open using concrete, which i think is what this bird is trying to do
If I'm not mistaken (resolution doesn't help), this bird is a Siriema. They use this movement to kill their prey (usually reptiles like snakes and lizards, but also frogs and small rodents). It is not playing, it is confused, thinking the ball is food.
It is not playing, it is confused, thinking the ball is food.
I am just picturing some alien biologist studying us
"This human is operating a video game called a FPS. It may seem like he is playing but really his instincts for self defense and attack are just misfiring. It isn't recreational it is just confusion"
And he is so eager doing so. Looks like the most important task all day with him runnig up to the path. He puts everything he got into smashing that ball onto the concrete as hard as he possibly can and is all fluffed up when that thing inevitably comes down again to nearly hit him. Almost like a toddler.