Scientists have observed a pair of male brown bears in captivity in Croatia that regularly engaged in oral sex over several years… The two, unrelated male bears in the study were orphaned soon after they were born in 2003 and put in captivity at a sanctuary in Kuterevo, Croatia. Over the course of six years and 116 hours of observation time, scientists led by Agnieszka Sergiel, of the Polish Academy of Sciences' Department of Wildlife Conservation, witnessed 28 acts of fellatio between the two male bears… The larger bear was always the one to receive fellatio. In many incidents, he appeared to reach orgasm from the sex act (which lasted for just a few minutes), as evidenced by muscular contractions and, well, fluids on the muzzle of the provider. When the deed was done, he often pushed the provider off with his hind legs or turned away.
