This pantropical booby is the smallest of the six booby species found worldwide. Named for its distinctive bright red feet (adults only), it has long wings, a wedge-shaped tail, and a conical bill with a slightly decurved tip. In its breeding range, it overlaps considerably Masked (Sula dactylatra) and Brown (S. leucogaster) boobies. All three species may be found nesting and feeding together, along with frigatebirds (Fregata). Flying fish and squid, caught by Red-footed Boobies in spectacular plunge dives, form a major part of the diet of all these seabirds.
A colonial tree-nester, the Red-footed Booby may nest in colonies of up to several thousand pairs. It builds its nests of twigs, grasses, and other green vegetation, generally laying only one egg. In this species there are several color morphs of adult plumage which are not related to subspecific classification; different color morphs coexist and even interbreed in some areas. Morphs range in color from an all chocolate brown bird to an all white one with black primaries and secondaries.
This species has suffered less from introduced predators on islands than have some ground-nesting species, but it is taken as food by local inhabitants in many areas of its range. While many colonies are seldom visited by scientists, there are indications that populations around the world are diminishing in size, as are those of most other tropical seabirds.