Saturday, 2 February 2013

Blue Footed Booby

order : Pelecaniformes      Genus & Species : Sulidae     Family : Sula nebouxii

Diving from the sky with purposeful grace, the blue-footed booby plunges through the surface of the sea and powers along underwater in pursuit of shoals of fish. A sleekly shaped body and self-sealing nostrils let the blue-footed booby plunge smoothly into the sea to snatch fish in its daggerlike bill. They found in Coastal and offshore waters of western North and South America, nesting on rocky coasts and islands from Baja California to Peru; an isolated population of about 10,000 pairs nests on Galapagos Islands. 

Habitat : Skies above tropical and sub-tropical waters off the western shores of North and South America, from Mexico to Peru, are the domain of the blue-footed booby for nearly all its life. Deep, cold currents flowing north from the Antarctic rise to the surface in this region. These cold upwellings are nutrient-rich and bring plentiful stocks of plankton, fish and squid to the surface — productive feeding grounds for the booby. Following currents as they change with the seasons, the booby keeps track of waters with the best fish supplies. It comes ashore only to breed on rocky, mainland coastlines or small, barren islets. 
Food & Feeding : Upwellings of cold currents, such as the Humboldt Current off Peru, yield a rich supply of pilchards, anchovies and sardines: principal food of the booby. Large shoals of these fish fall under repeated “dive-bomb” attack when boobies gather to feed.The blue-footed booby feeds in groups of up to 200 birds, often in the company of flocks of the Peruvian booby (Sula variegata). Sometimes, the booby feeds cooperatively, with several birds diving together at a given signal — usually a whistle by a male. As the first wave of boobies hits the water, the fish scatter, improving the success rate of the next wave of boobies. 
Behavior : The booby is highly sociable, and birds frequently encounter new individuals, especially in dense breeding colonies. The birds use complex displays to show aggression, recognition and friendship. A range of displays promotes and maintains bonds between mates. When flying toward his incubating mate in a colony, a male pushes his brightly colored, blue feet forward for her to see just before he lands. While facing her on the nest, he rocks back and forth, lifting one leg, then the other, to show off the blue webbing of his feet. Other displays include stretching vertically and turning the head sideways, as if avoiding eye contact. 
Breeding : Like other seabirds that depend on a food source that’s unpredictable in supply and distribution, the booby adapts its breeding cycle to suit its circumstances. It pairs with a regular mate, but doesn't nest at the same time each year.Apart from food availability, the onset of breeding is influenced by the time a pair has spent together and its success rate of rearing young. When it breeds, the booby gathers in large colonies. Each pair’s crude nest becomes surrounded by sun-hardened white droppings (guano).The booby doesn't develop brood patches (areas of bare skin on the breast) to warm the eggs during incubation. Instead, it uses the webs of its large feet, which have large numbers of prominent blood vessels, to transmit heat essential for incubation. The eggs are thick-shelled so they can withstand the full weight of an incubating bird. The two eggs hatch after 40 days and the brood is then fed for over three months. 


Bill : The mandibles of the long tapering bill have sharp cutting edges.These help the booby keep a hold on slippery fish. 
Eyes : The blue-footed booby has binocular vision, enabling it to pinpoint its prey with great accuracy. Both eyes face forward, focusing on the same objects — but from a fractionally different angle. By comparing the two images it receives, the brain determines the exact distance to all objects. 
Nostrils : Nostril openings on the top of the bill have become permanently closed and don’t function. Secondary nostrils on the sides of the bill, just in front of the eyes, close automatically by movable flaps when the bird dives into the sea. 
Feet : Broad webs between the toes of the bright blue feet provide strong paddle power while the booby swims.The feet also help keep the eggs warm during incubation. 
Juvenile : Young have browner body plumage than their parents, as well as dull colored feet and facial skin.When breeding, adults display their brightly colored parts, so the drab tones of a juvenile reduces the risk of it being mistaken for a breeding rival and injured in squabbles. 


Weight : 2 lbs.
Length : 2.5-3'
Wingspan : 5'
Sexual Maturity : 2-3 years
Breeding Season : Varies with location


“Booby” comes from the Spanish word bobo, meaning “stupid.” This refers to the birds’ lack of fear, making them easy to catch.