Male–Male Sexual Interactions Between an Adult and a Calf Killer Whale (Orcinus orca) of the Falkland Islands

Abstract

Same-sex behaviour has been documented in a wide range of animal taxa (mammals: reviewed in Dagg, 1984; birds: reviewed in MacFarlane et al., 2006) and is a common feature of social species (Poiani & Dixson, 2010). The functional and evolutionary significance of same-sex behaviour in animals is uncertain (Monk et al., 2019). Samesex behaviour can be used to promote social bonds between same-sex individuals, to maintain dominant/subordinate relationships without aggression or to promote reconciliation after it, and to improve reproductive skills of young individuals, or it can be a simple byproduct of sexual drive or arousal (reviewed in Bailey & Zuk, 2009). The presence and frequency of same-sex behaviours are related to a species’ life history (Poiani & Dixson, 2010), to their social and mating systems (MacFarlane at al., 2006), and to their level of parental care (MacFarlane at al., 2010).