Europe and Central Asia
6 Jul 2021

Seabird of the month - Northern Gannet (Morus bassanus)

 Northern gannet, Morus bassanus ©Martin Hejzlar
Northern gannet, Morus bassanus ©Martin Hejzlar
By BirdLife Europe & Central Asia
IUCN status: Least Concerned (LC)  
 
Global population: 1,500,000-1,800,000 mature individuals 
 
Description
 
Wingspan: 170-192 cm 
 
Life span: over 20 years 
 
Distinct features: When flying, this seabird can be recognised by their fast and uniform wingbeats alternated with shorter glides. Up close, you’ll see that adult Nothern Gannets are mostly white with a faint yellow wash on their heads and necks. The tips of their wings are black. The plumage of these seabirds transforms when they are five years old. Prior to that, juvenile Northern Gannets are wholly grey-brown with white spotting.   
 
Main prey: Northern Gannets prey on fish such as sardines and squid. When feeding, they can dive as deep as 24 meters with spectacular plunges into the sea. They are attracted to fishing boats to feed on fish caught in nets and on hooks. Because of this, these seabirds are a common victim of bycatch. Northern Gannets also follow cetaceans as a way to feed. The cetaceans push their prey up to the surface, where the Northern Gannets are waiting to join the feast. This phenomenon is called mixed feeding associations and is seen in several species of seabirds.  
 
Breeding
 
Northern Gannets mate for life. Young birds reach maturity between the ages of four and five. They begin breeding between late February and April. The females lay one single egg at the end of April, and the parents share incubation duties for six weeks. The egg hatches in early June and the chick fledges in late August and through September.  
 
Northern Gannets mainly breed in colonies and breeding sites, also called “gannetries”, on cliffs and offshore islands. They tend to stay loyal to their breeding sites and return to the colony they were born in. Experienced adults usually arrive at the breeding grounds earlier than juveniles, to re-bond with their mate and to defend their territory against rival seabirds.  
 
Their migration routes differ depending on their age. The timing and duration of their migration could also substantially change among individuals ranging between October and late February. The geographical location of “gannetries” can also influence the migration patterns of this seabird.  
 
Population distribution
 
The largest colony of Northern Gannets consists of around 75 000 pairs and is found in the Scottish island of Bass Rock. Other large colonies with between 15 000 and 60 000 pairs are found at St Kilda, and Ailsa Craig (Scotland), Grassholm Island (Wales), Bonaventure Island (Canada) Little Skellig (Ireland), and Eldey Island (Iceland).    
 
Main threats
 
  • Bycatch  
  • Collision with wind farms 
  • Direct persecution for harvest 
  • Waste and plastic pollution   
 
BirdLife and Northern Gannet
 
Our UK Partner RSPB has longstanding experience working with these seabirds, especially in one of their best-known nature reserves: Bempton Cliffs. You can watch the iconic aerial acrobatics they perform here, and catch a glimpse of their life at Bempton Cliffs here
 
Fun facts 
 
Northern Gannet billing display
Northern Gannets use their webbed feet to keep their egg warm and look adorable when doing it! Mated pairs engage in a “billing” display, a mutual greeting gesture, where the two birds stand breast to breast with their wings spread, and their necks and bills extended vertically, scissoring rapidly with their bills and calling loudly. But don’t be mistaken, these seabirds can also be violent. Aggressive fights between Northern Gannets of the same sex take place while the birds are nesting to defend their territory.  
 
 
Check the previous seabirds of the month:


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