Silver Gull (Chroicocephalus novaehollandiae)

This species can be found at both coastal and inland locations in a variety of habitats including artificial habitats such as rubbish dumps. It has a very varied, opportunistic diet including fish, marine and terrestrial invertebrates, seeds, insects and bird eggs. Kleptoparasitism has been observed. It breeds on small islands and points, mainly offshore, but also on freshwater and brackish lakes, and on causeways in salt-pans. The breeding season covers all months, with the exact timing varying depending on locality and age. It is colonial and occasionally solitary, with smaller colonies in the tropics (3-25 pairs) up to 3,000 pairs in southern Australia. Colony size depends on food availability. Individuals may wander widely outside the breeding season (del Hoyo et al. 1996).

L. n. scopulinus can be found on coasts, lakes, rubbish dumps, sewage outfalls, fishing piers, wet lawns and fields. It feeds mainly on euphausiid krill and other planktonic crustaceans in the breeding season, but also earthworms, insects and small fish. Outside the breeding season its diet is more variable, including fish, refuse and berries. It is also commonly a kleptoparasite. It begins nesting in July, laying between late September and December. Colonies can be very dense on the main islands, but small groups or even solitary birds are found on subantarctic islands, and can be found on rocky beaches, islands and stacks, and rarely on inland lakes. Almost all birds return to their natal colonies and retain mates from year to year. Birds returning early take large, central territories in the colony which are defended for a large period. After the breeding season most birds remain within 380 km of the colony, though juveniles may travel further (del Hoyo et al. 1996).