Yes, several non-human male mammals engage in anal penetration of other male animals. This behavior has been documented in various species, primarily among primates and some other mammals.
In Old World primates, male homosexual anal insertion has been recorded in gorillas, orangutans, and several species of macaques, including stumptail, rhesus, and Japanese macaques. This behavior is also observed in some New World primates, such as squirrel monkeys and spider monkeys. Among bonobos, anal intromission between males has been specifically noted. Additionally, male dolphins, including bottlenose dolphins, have been observed engaging in homosexual behavior involving genital rubbing and, in some cases, penis insertion into the anus of another male.
Other species exhibiting this behavior include male American bison, where courtship, mounting, and full anal penetration between males have been documented. Male rams have also been observed performing same-sex mounts with pelvic thrusting and ejaculation, indicating sexual motivation. In some cases, such as with European polecats, exclusive homosexuality with mounting and anal penetration has been observed, though it serves no apparent adaptive function.
These behaviors are often linked to social bonding, dominance establishment, or pleasure rather than reproduction.
Climbing on top of. That's a lot different than penetrating.
Here is what Brave AI had to say on the matter:
Do you have any counter-evidence?