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Last updated on April 25, 2014 at 1:22 EDT

Blue-footed Booby

The Blue-footed Booby (Sula nebouxii), is a seabird found along tropical and subtropical islands off the Pacific Ocean. Its most famous colony is on the Galápagos Islands, Ecuador. They also occur along the coast of California, USA. These specimens are strictly marine birds. Their only need for land is to breed, which is done along rocky coasts. This bird is quite abundant in concentrated areas and is not threatened or endangered.

The Blue-footed Booby is about 32 inches in length and weighs three pounds. Females are slightly larger than males. It has long pointed wings and a wedge shaped tail. The neck is strong and thick. Their yellow eyes are placed on either side of the bill and are slanted toward the front. Their binocular vision is excellent. The nostrils are permanently closed and specialized for diving. They breathe through the corners of their mouths. Their feet, as its name suggests, range from a pale turquoise to a deep aquamarine blue. The males and young have lighter colored feet then do the Adult female.

The courtship of the Blue-footed Booby is quite elaborate. The male flaunts his blue feet while dancing to impress the female. The male will spread his wings and stamp his feet on the ground. These birds are mostly monogamous but some do show bigamous tendencies. Each season they reunite at the breeding grounds which comes about every 8 to 9 months. During mating, the female parades around while the male points his head and tail skyward, with wings stretched back to show off to the female. During this ritual the males lift their feet high and throw their heads upward.

The female lays two or three eggs over a coarse of 10-15 days and both sexes take turns incubating the eggs, while a non-sitting bird keeps watch. Since the Blue-footed Booby doesn’t have a brooding patch on its belly, it uses its feet to keep the eggs warm. The Blue-footed Booby is one of only two species of booby that raise more than one chick. They must be fed frequently, so the adults must constantly hunt for fish. If they cannot bring enough food to feed all chicks, it will feed the biggest chick first, ensuring that at least one will survive. The male is the main food provider in the first part of the chick’s life because of his specialized diving skills. When demand is higher, the female will join in and eventually take over.

Plunge diving can be done from heights of 33-100 feet and even up to 330 feet These birds hit the water around 60 mph and can go to depths of 82 feet below the water surface. The prey is usually eaten while the bird is still under water. The diet of the Blue-footed Booby consists entirely of fish. They feed on sardines, anchovies, mackerel, and flying fish. They will also take in squid and offal. It dives into the ocean, sometime from high above and with great speed. It swims under water in pursuit of its prey. Sometimes they hunt in flocks of up to 12. When the lead bird spots a fish shoal in the water, it will signal the group and they will all dive together to catch the fish.

The Blue-footed Booby makes raucous or polysyllabic grunts or shouts and thin whistling noises. The males have been known to throw their head up and whistle as a female flies by. They also use their ritual displays as a form of communication.

Blue-footed Booby