Nutty: Boobies are birds with blue feet.
Billytea: Only the blue-footed variety. Aside from common or garden variety feet, there are also red-footed boobies. Tragically, this can lead to confusion within the booby community. Come mating time, you don't want to find you've shacked up with some strange booby. Thus, the courtship dance of the blue-footed booby (and if ever you get a chance to watch this, do) involves the male waddling up the female, turning side on, and hoisting up his foot as far as he can to allow her a thorough inspection - generally flapping madly to maintain his balance in the process. Then he turns around to present the other side, just in case the first one was just a fluke (ba dum). If he does all this without tripping, then he just might get some action.
You have to wonder if there was some incident in their past that led to fears of the red-footed boobies stealing in and ravishing their women. I like to think so, anyway.
[And I have nooooooo idea whether he's pulling our (blue) legs, either.]
[Attribution added]