Wednesday, 29 May 2013

Cross-dressing in the Animal Kingdom

by Dan Titmuss

"How cross-dressing helps male members of the animal kingdom find that lucky lady"

Ok, sneaky mating sounds kind of wrong; I get that, but it really is the best way to describe some of the tactics found in the animal kingdom. Let’s say you are dancing over to a lovely lady in a bar, only to find she is boogying on down with a massive good looking male. How on earth is one meant to get through to the beautiful maiden? Perhaps take some pointers from the animal kingdom.

For example, if you were a scorpionfly (Hylobittacus apicalis), the only logical explanation would be to make yourself look like a female. Bizarre answer you say? Larger males of the species catch beetles and give them as gifts to females in return for sex; however, catching these bugs is quite hard, especially for the smaller members of the species, and their gifts are often taken by larger scorpionflies anyway. These weaker males masquerade as females in order to steal gifts to give to females, allowing them to mate without the tricky process of catching and keeping the bugs. 

Meanwhile, in South Australia, the giant cuttlefish (Sepia apama) is trying a different tactic. Large males defend their chosen mate against other males, who also want to mate with her. This tactic would be a bad move for smaller males who can’t win a fight with males that are large and aggressive. The cuttlefish is famous for having an amazing ability to change colour by rapidly changing the physiology of specialized colour-changing cells in organs called chromatophores. This ‘chameleon-like’ ability can be used for social interaction, camouflage and to act as a warning to predators; however, the smaller males use this skill in a different way. Upon seeing a large male with a good-looking mate, they change the colour and texture of their skin to look like a female. The ‘in-drag’ male then swims up to the pair - its disguise allowing it to sneak past the larger male who presumably thinks himself lucky that he has two mates fighting over him - and mates with the female. This tactic is remarkably successful.

Some stag beetles (family Lucanidae) employ similar tactics. Some of the male stag beetles are born to look like female beetles, often producing pheromones to convince other males that they are fit, female mates. There have even been some reports of these beetles actually mating with other males in order to get the rival’s ‘seed’ out of the way, leaving the sneaky beetles to mate with prospective females.

But it’s not all about sex is it? Can’t we just have a cuddle at night to keep warm? Of course we can. In Canada, garter snakes (Thamnophis sirtalis parietalis) hibernate over winter. According to zoologist Robert Mason, “they’re cold to the bone” when they emerge in spring. What is the answer to getting warm? Some males actually pretend to be females so that males come to warm them up over the first few days after awakening from hibernation. I think I might give some of this a go!

*Cross-dressing in the Animal Kingdom appeared in Issue 1 of Synapse