To remain cool in hot weather, the Blue-footed Boobies will defecate on their feet (a behavior called urohydrosis). Additionally, they virbrate the skin of their throats by rapidly moving bones in their throat, which leads to evaporative cooling escaping through the open mouth. * Boobies with bluer feet appear to have more success in finding a mate than birds with duller blue feet. *The Blue-footed Booby lays its eggs on bare ground without nest. The incubating birds defecate while nesting, and the eggs are protected by a circular wall of excrement.