Sula nebouxiiblue-footed booby
Geographic Range
The blue-footed booby breeds on several arid islands off the western coasts of tropical America, Mexico, and northern South America.
- Biogeographic Regions
- neotropical
- oceanic islands
Habitat
The blue-footed booby inhabits arid islands in the Pacific ocean.
- Terrestrial Biomes
- scrub forest
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.
- Other Physical Features
- endothermic
- bilateral symmetry
-
- 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.
- Key Reproductive Features
- iteroparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Lifespan/Longevity
-
- Average lifespan
Status: captivity - 18 years
- AnAge
- Average lifespan
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.
- Key Behaviors
- flies
- motile
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.
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- IUCN Red List
-
Least Concern
More information
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.
- 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
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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.