Brown Booby Identification

Adult Description

  • Large, dark waterbird.
  • Long body, long neck, long tail.
  • Narrow, pointed wings.
  • Brown head, throat, chest, and upperparts.
  • White belly, vent, and wing linings

Immature Description

Juvenile is brown overall; belly ranges from mottled brown and white to mostly dark. Sharp line still visible between darker chest and lighter belly. Underwing coverts are pale. Bare parts generally dull gray.
Relative Size

Relative Sizegoose or largergoose-sized or larger
Measurements
  • Both Sexes
    • Length: 25.2-33.5 in (64-85 cm)
    • Weight: 33.5-63.5 oz (950-1800 g)
    • Wingspan: 52.0-61.0 in (132-155 cm)