The karoro or Southern Black Backed Gull is about the same size as a kahu (swamp harrier) but they are quite a different bird. They are the largest gull in New Zealand. Elsewhere they are called kelp gull. The photo above is of a young bird before it gets its adult colours.
Karoro are bold, handsome, black and white seabirds with a red-tipped, yellow bill and greenish legs and webbed feet. They are common southern hemisphere birds and can be found as far south as the Antarctic Peninsula. They are also widespread around New Zealand and are one of only two native birds not protected by the Wildlife Act.
They are good parents and look after their young for at least a month after fledging. Young birds, with their mottled feathers and black legs and bill, look similar to brown skua. They do not get their adult plumage until they are three years old.
Always on the lookout for food, they can be found on the coast, on wharves, where fishing boats dock, and at rubbish dumps, where they scavenge for scraps. You can find them raiding public litter bins for picnic throwaways – BBQ leftovers, unwanted pizza, hamburgers or fish and chips. They always seem to be hungry and are both scavengers and predators. They are clever and can learn, remember and pass on new habits. They have learnt to drop shellfish onto rocks to break them and to get the flesh hidden inside.
These gulls do not go fly far from land, unlike some seabirds e.g. the albatross which spends most of its life at sea.
A gull can drink both fresh and saltwater because it has special glands at the top of its bill that filter out the salt. Read about this handy adaptation here.
- Radio NZ Bird Watching – Black-backed gull
- NZ birds on line southern black-backed gull page
- Oiseaux-birds kelp gull page
- Wildscreen Arkive kelp gull page