Gannet
|
|
| Gannets | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
 Northern Gannet | ||||||||||||
| Scientific classification | ||||||||||||
| ||||||||||||
| Species | ||||||||||||
|
Morus bassanus |
The gannets are part of the family Sulidae. This is a group of seabirds, which is closely related to the boobies.
The three gannet species are now usually placed in the genus Morus, Abbot's Booby in Papasula, and the remaining boobies in Sula, but some authorities consider that all nine species should be considered congeneric, in Sula. At one time, the gannets were considered to be a single species.
The gannets are large black and white birds with long pointed wings and long bills. Northern Gannets are the largest seabirds in the North Atlantic, with a wingspan of up to 2 meters. They hunt fish by diving from a height into the sea and pursuing their prey underwater. Gannets have a number of adaptations which enable them to do this: they have no external nostrils; they have air sacs in their face and chest under their skin which act like 'bubble-wrap', cushioning the impact with the water; their eyes are positioned far enough forward on their face to give them binocular vision, allowing them to accurately judge distances. Gannets can dive from a height of 30m, achieving speeds of 100 km/h as they strike the water, enabling them to catch fish much deeper than most airborne birds.
These are colonial breeders on islands and coasts, which normally lay one chalky blue egg.
It takes five years for gannets to reach maturity. First-year birds are completely black, and subsequent sub-adult plumages show increasing amounts of white.
This group is related to other Pelecaniformes as below:
ORDER PELICANIFORMES
- Family Pelecanidae - pelicans
- Family Sulidae - gannets and boobies
- Genus Morus
- Northern Gannet Morus bassanus or Sula bassana
- Cape Gannet Morus capensis or Sula capensis
- Australian Gannet Morus serrator or Sula serrator
- Genus Papasula - Abbot's Booby
- Genus Sula - other boobies
- Genus Morus
- Phalacrocoracidae - cormorants
- Fregatidae - frigatebirds
- Anhingidae - Anhinga and darters
- Phaethontidae - tropicbirds
The most important nesting ground for Northern Gannets is the United Kingdom with about two thirds of the world's population. These live mainly in Scotland. The rest of the world's population is divided between Canada, Ireland and Iceland, with small numbers in France, the Channel Islands and Norway. The biggest Northern Gannet colony is in the Scottish islands of Saint Kilda; this colony alone comprises 20% of the entire world's population.es: alcatraz