Midway Atoll National Wildlife Refuge
Pacific Region
 

Birds of Midway Atoll

Red-footed Booby / Sula sula rubripes

Photo of red-footed booby

Description

Smallest of all boobies. Polymorphic; few seabirds display such a variety of color phases. Legs/feet red. Bill is pale blue. Juveniles are wholly brown or blackish gray with black bill and facial skin. Gray legs. Immature have patchy underwings without definite pattern, white back, mottled gray-brown head, and red or brownish legs. Length: 66-77 cm (26-30 in); wingspan: 91-101 cm (36-40 in); average life span: 22 years.

Red-footed Booby
Photo credit: Sandra Hall/USFWS
  

Midway Population

Midway island's red-footed boobies are a white color morph. Adult birds have white body and tail plumage. Upperwings have black primary and greater secondary coverts. About 563 pairs nest on Eastern Island (2006), may be seen flying or resting on Sand Island.

Feeding Habits

Feeds by diving vertically into the water and rarely within sight of land. May dive up to 30 meters to pursue prey. Prey primarily on flying fish and squid. Feeds singly or in mixed species flocks. Feeds anytime during the day and after dark.

Breeding

Breeding season ranges from late January through September. Nests are built of twigs and sticks exclusively on tops of shrubs. Naupaka (Scaevola sericea) and tree heliotrope (Tournefortia argentea) are commonly used shrubs on Midway. May nest in same shrubs as Great Frigatebirds (Fregata minor).

Begin breeding at 4 years of age. Monogamous. A single, chalky, white egg is laid. Re-laying can occur if first egg is lost. Lacks brood patch. Incubates with feet. Male and female share incubation duties. Individual incubation shifts average about 24 hours. Incubation period ranges between 42-45 days. Chick feeding occurs once every 16-18 hours. Fledging ranges between 95-101 days after hatching. Post-fledging care and feeding can continue for 1 to 4 months.

Last updated: May 21, 2009