Hawaiian Birds and Red-footed Booby

The Red-footed Booby (‘A) has long pointed wings and a relatively long, wedge-shaped tail. In Hawai’i the species nests on Kure Atoll, Midway Atoll, Peal and Hermes Reef, Laysan, Lisianski, Gardner Pinnacles, French Frigates Shoals, Necker, Nihoa, Kaua’i, O’ahu, and Johnston Atoll. They are also found elsewhere in the Pacific Ocean, Atlantic Ocean, and Indian Ocean.

Almost all Hawaiian individuals are predominately white except for brownish black primary and secondary wing feathers, but several color morphs exist ranging from all brown to all white to brown bodies with white heads, brown bodies with white tails, brown bodies with white head and tail. Their feet and legs are orange to red, the bill is bluish except for the base of lower mandible which is pinkish, and around bill ranges from pink to red and blue. Their flight is characterized by strong flapping interspersed with gliding for as much as a mile. The sexes are very similar except females are larger than males, and male has a lime green or bluish green patch under and in front of eye prior to breeding, which fades once incubation begins.

The Hawaiian name for this booby is ‘A, presumably named after the species call. They are quite vocal, but with a limited vocabulary which consists of loud screeching squawks and guttural noises, mostly consisting of low “aaks”. A major part of their diet is flying fish and squid, caught in spectacular plunge dives from 12 to 24 feet over the water. It is believed morphs may have different fishing advantages – birds with dark bellies may be more difficult for fish to detect at dusk and after dark, while those with white bellies may be more difficult to detect during daylight.

The Red-footed Booby (Sula sula) breeds in colonies ranging from ten to ten thousand pairs, building their nests of twigs, grass and various vegetation off the ground in shrubs or trees. On Kaua’i, these birds can be observed at Kilauea Point National Wildlife Refuge on the North Shore. They may be encountered at any time of the day and any month of the year, but a visit between November and June will provide the greatest numbers. In the evenings when birds return from feeding trips, several thousand birds may be seen over the cliffs and hillside at the refuge.