(Credit: U. S. Geological Survey)

Brown Booby - Sula leucogaster

Identification Tips:

  1. Length: 23 inches Wingspan: 56 inches
  2. Sexes similar
  3. Pelagic bird only coming ashore to breed
  4. Large bird that dives for fish from air
  5. Takes 2 to 3 years to reach adult plumage

Adult

  1. Dark head, breast, mantle, and tail
  2. White belly cleanly separated from dark breast
  3. Underwings white with dark border
  4. Large, yellow, pointed bill
  5. Yellow legs and feet

Immature

  1. Plumage similar to adult but belly is slightly paler than breast

Similar species:

Adults are quite distinctive with their bold dark head and breast cleanly separated from the white belly. Immature boobies of other species are very similar to Brown Boobies. Young Brown Boobies have darker bellies than Masked and Blue-footed Boobies. As Brown Boobies age, the distinctive breast band becomes more apparent. Young Red-footed Boobies are also quite dark but are smaller, and have even darker bellies and underwings. First-year gannets are larger and lack the breast demarcation line.