Yeah, robins are friendly with humans, but are fiercely territorial with other robins and if neither backs down in a fight, they can fight to the death.

There was a poem I read once and I can't find it anywhere. It was about a robin strutting proudly and ended with the reason being that "he killed his father in a fight". I wish I could find it again!

I have a fun fact about robins!

https://autistics.life/@SilverArrows/114763194894486510