Just read this.

If he starts acting distressed I'd worry about it impacting in his digestive tract somewhere & you'd have to get him to a vet who will treat birds, at ONCE.

But if he continues to act okay & doesn't look uncomfortable, maybe he can pass it out. As a little kid, I had a big pet rooster grab & swallow a big pencil eraser, maybe1-1.5" long by 1/2-3/4" wide & he was fine.

Why don't you confine him so you can see if he poops it out? It would also let you keep an eye on him to see if he starts suffering from the thing getting stuck inside. Don't mess around if he starts acting sick or like he hurts--call a vet & get him seen at once or he could rupture & die painfully.

Hope he's alright.

My Mothers rooster and chickens ate almost a whole syrofoam cooler back during the summer as the wind blew it from some rafters and nothing happened to them. We also caught them eating a Styrofoam large cup and almost had eaten the whole thing and that was a year ago. They must have some really tough Insides because they are and in no way seem to have had any internal stress. I hope this eases your mind a little anyhow. God Bless

Thank you very much for your comments and advice. More than 24 hours have lapsed and my rooster, Felipe, looks fine.
Thanks again

Oh, that's good to hear! Thanks for the report. I guess if they can deal with big hard-shelled bugs like cicadas a chunk of styrofoam or a pencil eraser is nothing ;)

Now tell Felipe what a bad boy he's been!

Not toxic so just a choking hazard. Mine get into it every once in awhile-cooler in the backyard, packing...they love the stuff so you gotta watch them. I don`t know if it`s the color or what that attracts them.
Tally Ho!