"Robocrab" or "You still can't trust a fiddler crab"

Researchers wanted to learn the factors affecting mate selection in fiddler crabs, specifically the Australian Uca mjoebergi fiddlers (thanks, Laurinda, for sending me this article!). You see, female fiddler crabs are VERY picky when it comes to choosing a male. Also, it's just plain fun to watch fiddler crab behavior! 

So the researchers mimicked the crabs in two ways:

1. make a robocrab arm to wave to the ladies at different sizes and speeds

2. lie to the ladies, as male fiddler crabs are apt to do, by making them think they are legitimate mates and not just some flailing piece of machinery (read another example of fiddler crab dishonesty here).

Are you a man or a machine?

Actually, you look like a pretty cute male U. mjoebergi!

It's actually pretty cool. Not surprisingly, females preferred "males" with larger claws, but they also liked faster waving speeds. Researchers were then able to learn that males purposefully situate themselves around smaller, slower neighbors in order to make themselves look better! They even go so far as to protect their weaker neighbors, but with an ulterior motive, not "Oh, I'm just a nice guy".

what, you think Ryan Gosling is the only one to say "Hey girl"?

Another study showed males "eavesdropping" on their neighbors to learn where the ladies are! Fiddler crabs. Pfft.

(Watch the robocrab videos here.)