Overview
- A literature-based comparison spanning 491 non-human primate species found evidence of same-sex sexual behavior in 59 species, with repeated interactions recorded in 23.
- Documented interactions included mounting, genital touching, and oral sex observed in wild populations.
- The behavior appeared more common in species facing dry or food-poor environments, higher predation risk, longer lifespans, strong dominance hierarchies, and greater male–female size differences.
- Co-author Vincent Savolainen said the findings counter the notion that such behaviors are rare or confined to captivity, describing them as part of normal primate social life.
- The study, published in Nature Ecology & Evolution with an accompanying commentary by Isabelle Winder, emphasizes correlational results and notes that relevance to humans remains uncertain.