Blue-footed boobies can also be distinguished because the females have a ring of dark pigment around their pupils, making them look bigger than those of the males. Red-footed boobies are dimorphic for plumage. All three birds have similar body shapes, and they lead similar lifestyles, but refrain from competing with one another because they fish in different areas. The distributions of their fishing grounds influences the distribution of their nesting sites. Because of their distribution, it is typically the blue-footed booby that visitors tend to see fishing.
Boobies are plunge divers and their dive is spectacular.
Blue-footed boobies dive in remarkably shallow water, and they use their large tails to pull themselves out of the dive. One usually sees individual birds fishing, but it is not at all uncommon to see a small group of boobies flying in formation, heads down, looking for fish. Occasionally one can see large flocks of boobies fishing together. It is called the diver. They resemble the small kind of booby, and something similar to the kind which is described at the Lobas Islands, called Bonaparte's army, excepting they are of rather a darker colour on the breast and neck, and their beaks and feet are of a prussion blue.