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Fiddler Crab

Fiddler crabs may be little, but they have one big appendage, the CLAW! A weapon if ever there was one. Like a lance or an over-sized boxing glove, something about it just screams MAN. So it fits that male fiddlers are the gender so endowed.

Females have two little feeding claws. No giant claw. No weapon of any kind. Unless, of course, you count her good looks and killer form. Turns out that’s all she needs.

This research comes from the ANU (me own university), and there’s apparently a fiddler crab expert here that I have to meet. His name is Richard Milner, and the paper was published in Biology Letters.

ResearchBlogging.orgRichard N. C. Milner*, Michael D. Jennions and Patricia R. Y. Backwell (2009). Safe sex: maleāˆ’female coalitions and pre-copulatory mate-guarding in a fiddler crab Biology Letters (6), 180-182 : 10.1098/rsbl.2009.0767

Fiddler crabs live in burrows, which are a place to hide when predators come along. Burrows are in high demand, and males will fight for squatting rights. Females can’t fight without a big-ass claw, instead they take over empty burrows.

Burrow-owning females would be sitting ducks for homeless males to come and kick them out, if it weren’t for the male next door.

Male fiddlers will defend the territory of nearby females. The study showed that if the intruder is a male, the neighbour will try to fight him off 95% of the time. That compares to just 15% of the time when the intruder was female. So male fiddlers like to be surrounded by female fiddlers. Go figure.

When picking a sexual partner, female fiddlers chose a neighbour who shares a territory border with her 85% of the time. The remaining 15% was made up of strangers, burrowless males and non-neighbour residents.

Part of that could be convenience, as females are at risk of predation while they search for a mate. Part of it could be gratitude. Part of it could be white knight syndrome, in which the big manly fiddler roughly dispenses of all piddly competition to claim the hand of the fair maiden. Damn I have a problem with personifying animals.

It boils down to one thing: Fiddlers exchange sex for protection. It makes me wonder whether some human relationships amount to much the same thing. Give me your thoughts and complete the following: Humans exchange sex for