Animals Engaging in Anal Sex

Are there any animals which have been observed engaging in penetrative anal sex?

[I’m aware that there are many animals which engage in homosexual-type behaviours. I’m asking about anal sex specifically, whether with same or opposite sex. And of course, this applies to animals which have distinct anuses, versus cloacas or other arrangements.]

Bison, giraffes, and polecats for a start.

Interesting, in reference to Amazonian dolphins:

Are humans animals?

I haven’t made a detailed study of animal sodomy, but I do know that the hedgehog can never be buggered at all.

Oh, come on. SOMEONE had to do it, might as well be me.

These animals engage in ass sex all the time.