Cape Gannet

The Cape gannet, Morus capensis, is a majestic seabird belonging to the family Sulidae. This large bird is adorned with striking black and white plumage, complemented by a distinctive yellow crown and hindneck. Its pale blue bill, pointed and finely serrated near the tip, is a remarkable adaptation for its high-speed diving when fishing.

Identification Tips

Adult Cape gannets can be recognized by their impressive size, with a body length of 84–94 cm (33–37 in) and a wingspan of 171–185 cm (67–73 in). They weigh approximately 2.6 kg (5.7 lb). The species is characterized by its snow-white body contrasted with a black tail, primaries, and secondaries. The golden crown and nape, which fade to white on the neck, are distinctive features. Juveniles and immatures display a dark brown plumage with a pale bill.

Habitat

Cape gannets are typically found nesting in large, dense colonies on flat islands or steep slopes, such as those of Mercury Island off Namibia.

Distribution

The breeding range of the Cape gannet is confined to six islands along the coast of Southern Africa. Non-breeding individuals range from the coastal waters off the Gulf of Guinea to Mozambique, usually not venturing more than 100 km offshore.

Behaviour

Cape gannets are powerful fliers, often engaging in flap-gliding flight. They are known for their elaborate greeting rituals, which include stretching their bills and necks skyward and gently tapping bills together.

Breeding

Cape gannets are monogamous, with pairs possibly remaining together across seasons. They lay a single bluish egg, which both parents incubate using their blood vessel-rich foot webs. The chick, initially naked and blind, grows rapidly, often outweighing the adult by eight weeks of age.

Similar Species

The Cape gannet can be confused with the Australasian gannet, which has a shorter black stripe down the throat and less black on the face. It also resembles the northern gannet, which has an entirely white tail and wings with only black tips.

Diet and Feeding

Cape gannets are piscivorous, plunge-diving from considerable heights to capture fish, hitting the water at speeds between 40 and 120 km/h (25 and 75 mph).

Conservation status

The Cape gannet is currently listed as Endangered on the IUCN Red List. Populations have experienced significant declines, particularly on Namibian islands, while South African populations have shown increases.