Blackcap and Robin (no, not Batman and Robin). The Robin(s) hate(s) the female Blackcap and shoo her off the territory.
"Are you a Bluecap?"
The male Blackcap finds it easier to tolerate other diners . . .
unlike the hen, he is not chased away by the resident Robin.
"You've a blacker cap than I have."
Sometimes he swears at intruders.
The Nuthatch is seen as a threat but is not intimidated and is interested only in the seeds.
The Blackbird and Blackcap tolerate each other.