Red-billed gull
The red-billed gull is a fairly small gull with an all-red bill, red eye ring, red legs and feet, pale grey wings with black wingtips. The rest of the body and tail are white. There is virtually no visual difference between the male and female birds. Juvenile gulls have a dark brown bill with only hints of red, making them difficult to distinguish from the black-billed gull. The legs are also brown and there are brown spots on the grey wings. It is the smallest gull commonly seen in New Zealand. The population is estimated at 500,000. It was formerly considered a distinctive species, but looks similar to the silver gull found in Australia, and is now considered to be a subspecies. Behaviourally, the red-billed gull is a typical gull. It is an aggressive scavenger and kleptoparasite. Since European settlement its numbers have increased, especially around coastal towns and cities where it can scavenge from urban waste. It normally feeds on small fish, shell fish and worms (from pastures), and sometimes berries, lizards and insects. They nest from October to December in colonies on the coast, either on islands or rocky headlands, cliffs and beaches. The birds form pair bonds which endure across seasons, but there is a certain amount of extra-pair copulation. Courtship feeding is an important part of the preparation for mating. Nests are well formed and may be constructed of seaweed, grasses, leaves and ice plants. Generally two to three eggs are laid, their colour ranges from brown to grey with light and dark brown spots all over. The bird generally lives up to 12 years, although individuals have also been found living up to 30 years.
Distribution
It was formerly considered a separate species but is now usually treated as a subspecies of the silver gull ("Chroicocephalus novaehollandiae").