Why is the booby so called?

Because it is an indolent, senseless, and cowardly bird, submitting to all sorts of depredations upon its happiness with indolent imbecility ; yet it is occasionally, when much excited, ferocious. The man-of-war bird no sooner perceives it in the air, than it pounces upon it, not to destroy it, but to make it disgorge the fish which it has swallowed, which is caught by the voracious plunderer before it reaches the water. - Jennings.