A Beginner’s Guide To Seabirds
By Scuba Diver Life
If you’re an avid boat diver, you’re likely no stranger to lengthy surface intervals, liveaboard vacations, or long trips to and from dive sites. Cultivating an interest in seabirds is a great way pass your time above the water, allowing you to appreciate another aspect of the marine environment. Wherever you are in the world, there are birds to be seen at sea — in estuaries, on the coast, or even many miles from land in the open ocean. Each of these species boasts adaptations that allow them to survive in environments that are often as harsh as they are beautiful. Below are a few of the world’s most easily distinguishable seabird families, presented with the hope that this may spark in the avid divers who read it a new passion for the ocean’s magnificent avian residents.
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Albatrosses
By Scuba Diver Life
Among the largest of all flying birds, albatrosses are immediately recognizable by their impressive wingspan; the wingspans of the largest great albatrosses are the largest of any bird at over 11 feet long. The IUCN currently recognizes 22 albatross species, and all are associated with the Southern Ocean and the North Pacific where they nest in colonies on remote oceanic islands. Albatrosses mate for life, a considerable achievement since scientists think them to be among the longest lived of any seabird. In addition to their large size, albatrosses are easily distinguishable by their long, strong beaks, which are hooked to help the bird seize food from the sea’s surface. There’s also a tube or ‘nostril’ on either side of the beak that the bird uses not only to smell, but also to accurately measure its airspeed while in flight. This ability, when used in conjunction with the albatross’ enormous wing span, allows these birds to fly incredible distances by soaring and gliding using the air currents generated by wind and waves.
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Penguins
By Scuba Diver Life
Perhaps one of the easiest seabird groups to identify, all penguins have black backs and white fronts, in a camouflage tactic known as countershading. This helps the penguin to remain undetected by ocean predators while in the water by making it difficult to spot against the surface when seen from below. All penguins are flightless, with rigid vestigial wings that are ideally adapted to make these birds extremely agile in the water. There is some debate among scientists as to how many extant penguin species there are; currently, it is thought that there are between 18 and 20. Many of these species, like the emperor and the king penguin, are confined to Antarctic waters, but some, such as the African penguin and the little penguin, may be seen while diving in various Southern hemisphere locations. One species, the Galapagos penguin, is found north of the Equator in Ecuador’s Galapagos Islands.
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Gannets and Boobies
By Scuba Diver Life
Gannets and boobies are closely related coastal seabirds found primarily in the tropics and subtropics (boobies) and also in more temperate regions (gannets). They are diving birds, and so are perfectly adapted to plunge from a great height into the ocean without sustaining any injuries. Gannets and boobies both have internal nostrils that prevent water from entering their nasal cavity while diving, as well as excellent binocular vision that allows them to judge distances more accurately. Both have long, narrow wings and are exceptionally streamlined.
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Gannets and Boobies, cont.
By Scuba Diver Life
They are similar in size and shape, but gannets are easily identifiable by their creamy white plumage, pale yellow heads and blue eyes outlined in black. The three species of gannet are found in the North Atlantic and off the coasts of Southern Africa and Australasia respectively. Boobies are typically brown and white, often with brightly colored feet. They are distributed widely throughout the tropics.
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Terns
By Scuba Diver Life
Often described as one of the most graceful seabird families, various species of tern are found all over the world from the Arctic to the Antarctic. There are tern breeding colonies on every continent, and many species complete long-distance annual migrations to reach their traditional breeding site. These are relatively small seabirds, with the largest species (the Caspian tern) having a maximum wingspan of less than 3 feet (1 m). Typically, terns are light gray or white in color with a distinctive black cap, although some species (like the Inca tern) have atypically dark plumage. Depending on the species, terns may have black, yellow, orange or red bills, but all have longer, narrower bills than their close relatives, the gulls. Their small size, long wings and gracefully forked tails best identify terns. They are slender, aerodynamic birds that breed in noisy colonies, and typically dive for their food, sometimes in conjunction with predatory fish or dolphin pods.
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Cormorants and Shags
By Scuba Diver Life
This group of aquatic birds numbers some 40 different species, many of which are known interchangeably as cormorants or shags depending on the country in which they are found. Believed to have descended from freshwater birds, modern-day cormorants and shags are coastal rather than oceanic. They are typically dark colored, and range in size from 18 inches to 3 feet (45 cm to 1 m) in height. Cormorants and shags enjoy a global distribution, and can be seen in most coastal locations except for the islands of the central Pacific. Their long, sharply hooked bills, their relatively heavy bodies and slender, snake-like necks easily identify them.
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Cormorants and Shags, cont.
By Scuba Diver Life
These birds are adept divers, beginning their dive from the sea’s surface and reaching depths of up to 150 feet (45 m). After diving, most cormorant and shag species spread their wings in order to dry them, a distinctive behavioral trait that is a trademark of these birds.
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