Gannets Temporal range: Early Miocene to recent |
|
---|---|
Northern gannets on Heligoland
|
|
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Suliformes |
Family: | Sulidae |
Genus: |
Morus Vieillot, 1816 |
Species | |
Synonyms | |
Moris |
Moris
Having a maximum lifespan of up to 35 years,Gannets are seabirds comprising the genus Morus, in the family Sulidae, closely related to boobies. "Gannet" is derived from Old English ganot "strong or masculine", ultimately from the same Old Germanic root as "gander".Morus is derived from Ancient Greek moros, "foolish", due to the lack of fear shown by breeding gannets and boobies allowing them to be easily killed.
The gannets are large white birds with yellowish heads; black-tipped wings; and long bills. Northern gannets are the largest seabirds in the North Atlantic, having a wingspan of up to 2 metres (6.6 ft). The other two species occur in the temperate seas around southern Africa, southern Australia and New Zealand.
Gannets hunt fish by diving into the sea from a height and pursuing their prey underwater. Gannets have a number of adaptations which enable them to do this:
Gannets can dive from a height of 30 metres (98 ft), achieving speeds of 100 kilometres per hour (62 mph) as they strike the water, enabling them to catch fish much deeper than most airborne birds.
The gannet's supposed capacity for eating large quantities of fish has led to "gannet" becoming a description of somebody with a voracious appetite.
Gannets are colonial breeders on islands and coasts, normally laying one chalky, blue egg. Gannets lack brood patches and they use their webbed feet to warm the eggs. 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.
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, including the Shetland Isles. The rest of the world's population is divided between Canada, Ireland, Faroe Islands and Iceland, with small numbers in France (they are often seen in the Bay of Biscay), the Channel Islands, Norway and a single colony in Germany on Heligoland. The biggest northern gannet colony is in the Scottish islands of St Kilda; this colony alone comprises 20% of the entire world's population. Sulasgeir off the coast of the Isle of Lewis, Bass Rock in the Firth of Forth, Grassholm in Pembrokeshire, Bempton Cliffs in the East Riding of Yorkshire, Sceilig Bheag, Ireland and Bonaventure Island, Quebec are also important northern gannet breeding sites.