Group sex appears to be another evolutionary strategy. Every spring in southern Manitoba, tens of thousands of red-sided garter snakes (Thamnophis sirtalis parietalis) emerge from their underground hibernation dens and end up writhing in large “mating balls”. When a female garter snake emerges, she releases a pheromone that attracts hundreds of male snakes towards her. As if that isn't enough, scientists discovered that some male snakes “cross dress”; they release female-like pheromones to attract other males. One common assumption has been that pheromone-releasing males gain a reproductive advantage by diverting fellow male snakes attention from the female. But Australian and US researchers think this solves a more mundane purpose – male snakes pose as females to warm up quicker and to reduce their exposure to predators.
The mourning cuttlefish (Sepia plangon) takes its cross dressing even further. This cephalopod, found in the waters off the eastern coast of Australia, controls the appearance of its skin with exquisite precision. When a male cuttlefish attempts to seduce a nearby female, he offers her a courtship display by controlling the arrangement of pigments that appear on the surface of his skin. If a rival male approaches, he changes his skin on the side facing the rival to appear female. The female still sees the courtship display, the intruder, however, thinks there are two females – leaving the original male to complete his reproductive business in peace.
Our societies may look down upon certain sexual interests as odd, weird, gross, or just plain silly. But as with friendships, play, and even teenage kicks, investigating other species helps us to hold a magnifying glass of sorts – albeit one with a bit of distortion – up to our own behaviours. And if we squint real hard and tilt our heads to the side we might be able to catch a glimpse of the common threads connecting us with our non-human cousins. Even if it offends or challenges our norms.