The Australian gull reaches a length of 36 to 44 cm. The length of the wings is from 26.8 to 31.9 cm. The wingspan is from 91 to 96 cm. The weight of the bird is from 265 to 315 g. The males are slightly larger and heavier than the females [ 4] .
In adult birds, the head, tail and lower body are white. The back and coverts are pale gray. The wings are black with large white spots. Beak and legs are bright red. Eyes are yellowish white with a thin red eye ring. Non-breeding birds are usually less brightly colored and have a darker ocular ring. In addition, outside the breeding season on the beak, a dark spot of various shapes is noticeable.
Young birds have a scaly, brownish pattern on the wings. Otherwise, they are very similar to sexually mature birds. The beak and eyes are usually black to dark brown in color, and the legs are still tan [4] .
Australian gull is common on the coast, islands and large lakes of Australia, Tasmania and New Caledonia. Birds migrate for short distances.
The bird population is growing. In the early 1990s, approximately 500,000 pairs nested in 200 breeding colonies in Australia [4] .
Australian gull eats worms, fish, insects and crustaceans.
Australian gull nests in colonies, only occasionally pairs nest separately. Often birds mate with last year’s partners and use the same nesting place as a year earlier. Nests are usually built on the ground, but can also be found in bushes at a height of up to 2.5 m above the ground. The species is able to grow brood year round. Typically, breeding time in western Australia falls from March to November.
In clutch from one to five eggs. Hatching lasts from 21 to 27 days. Young birds stay 4 weeks in a breeding colony. Then another two weeks the parent birds feed them outside the breeding colony. Between 3 and 4 years old, birds become sexually mature.
As of February 2018, 3 subspecies are distinguished in the form [1] :
- Chroicocephalus novaehollandiae forsteri (Mathews, 1912)
- Chroicocephalus novaehollandiae novaehollandiae (Stephens, 1826)
- Chroicocephalus novaehollandiae scopulinus (JR Forster, 1844)
Larger subspecies C. n. fosteri nests in northern Australia, in New Caledonia, and in Luyota .
