Same-sex courtship behaviors in male-biased populations: Found more male-male sexual interactions in male-biased populations and a significant decrease of these behaviors after consecutive days of observation

Same-sex courtship behaviors in male-biased populations: evidence for the mistaken identity hypothesis. Anthony Macchiano, Imran Razik, Maria Sagot. acta ethologica, https://link.springer.com/article/10.1007/s10211-018-0293-8

Abstract: Same-sex sexual behaviors (SSSB) have been recorded in nearly all major animal groups and are often found in populations with skewed sex ratios (SR). Here, we study the role of sex ratios in the frequency of SSSB to better understand the conditions that give rise to such puzzling behaviors. We observed SSSB in multiple populations of the common fruit fly (Drosophila melanogaster) after manipulation of sex ratios. We also recorded male responses after being pursued by other males. We found more male-male sexual interactions in male-biased populations and a significant decrease of these behaviors after consecutive days of observation. Males pursued by other males reacted to such encounters. Our results provide support for the mistaken identity hypothesis, in which males are unable to differentiate between sexes at first encounter. With this work, we help elucidate possible social conditions that facilitate the appearance of such intriguing behaviors in nature.

Keywords: Same-sex interactions Homosexual behavior Sex ratios Drosophila melanogaster