Sula nebouxiiblue-footed booby

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Geographic Range

The blue-footed booby breeds on several arid islands off the western coasts of tropical America, Mexico, and northern South America.

Habitat

The blue-footed booby inhabits arid islands in the Pacific ocean.

Physical Description

The blue-footed booby is a comical-looking tropical seabird with bright blue webbed feet and bluish-grey facial skin. The head of the bird is a pale cinnamon-brown with dense white streaks. On the back of the neck, there is a white patch where the neck connects to the mantle. A booby has long, brown, pointed wings that can measure an average152 cm across. The lower breast , central tail feathers, and underparts are white. Its blue tapered bill has serrated edges that enables the bird to tightly grasp fish.

  • Average mass
    1530 g
    53.92 oz
    AnAge

Reproduction

The blue-footed booby breeds year round. Breeding begins with elaborate courtship displays by the male. He flies around his territory, flaunting his blue feet in an exaggerated high-stepping walk, and presents pieces of nest material to the female. After making a courtship flight, the male flashes his feet at the female as he lands. Then each bird tilts its bill up towards the sky and the male gives a piercing whistle. The female responds with groaning calls, and mating follows shortly afterwards.

The female lays her eggs in a shallow depression on flat ground. Clutch sizes vary from two to three eggs. Unlike most birds, the blue-footed booby lacks brooding patches (patches of bare skin that transmit heat to the eggs). As a result, the booby uses its webbed feet, which have an increased blood supply, to incubate the eggs. When the eggs begin to hatch, the female supports them on the top of her feet. The young remain on her feet for an entire month. Both parents feed the chicks by regurgitating fish and allowing the chick to remove it from their bills. The chicks are fed continuously, and if there is a food shortage, the largest chick is be given the food.

  • Average eggs per season
    2
    AnAge
  • Average time to hatching
    41 days
    AnAge

Lifespan/Longevity

  • Average lifespan
    Status: captivity
    18 years
    AnAge

Behavior

The blue-footed booby feeds singly or communally. It also likes plenty of distance between its nest and those of others in the colony.

Communication and Perception

Food Habits

The diet of the blue-footed booby consists solely of fish. When gliding over the surface the water, the blue-footed booby keeps its beak at a downward angle, watching for fish. The species is known for its spectacular dives from heights of up to 80 feet. Barely making a splash when hitting the water, the blue-footed booby resurfaces several yards away with a fish. Unique among other boobies, the blue footed booby can dive below the water from a surface swimming position to catch fish. Despite its habit of feeding alone, the blue-footed booby cooperate in flocks to hunt fish. When one bird in the flock spots a fish, it gives a whistle to alert the others. Then the rest of the flock follows the first diving, into the water with perfectly synchronized movements. Interestingly, the male and the female are adapted for catching prey of different sizes. The male, being smaller, performs shallow dives, while the heavier female is able to make deeper dives farther offshore.

Conservation Status

Breeding pairs number under 40,000 and half of this population resides on the Galapagos Islands, where the species is legally protected. Egg collectors pose minor threats to populations elsewhere.

Other Comments

The blue-footed booby got its name from the spanish word bobo, which means stupid fellow. Its lack of fear and clumsiness on land has made the species vulnerable to man.

Contributors

Marie S. Harris (author), University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

References

Harrison, Peter. Seabirds. A.H. & A.W. Reed Ltd., 1983.

Tuck, Gerald. A Field Guide to the Seabirds of Britain and the World. William Collins

Co. Ltd., 1978.

Wildlife Fact File. Group 2. Card 14.