Chroicocephalus novaehollandiae

Summary 6

The Silver Gull (Chroicocephalus novaehollandiae) also known simply as "seagull" in Australia, is the most common gull seen in Australia. It has been found throughout the continent, but particularly at or near coastal areas. The South African Hartlaub's Gull (C. hartlaubii) and the New Zealand Red-billed Gull (C. scopulinus) were formerly sometimes considered to be subspecies of the Silver Gull. As is the case with many gulls, it has traditionally been placed in the genus Larus...

Distribution 7

Subspecies and Distribution:

    * forsteri Mathews, 1912 - N Australia; New Caledonia and Loyalty Is. * novaehollandiae Stephens, 1826 - S Australia and Tasmania.


Habitat and ecology 8

Habitat and Ecology

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).

Systems
  • Terrestrial
  • Freshwater
  • Marine

Behaviour 9

Iucn red list assessment 10


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2014

Assessor/s
BirdLife International

Reviewer/s
Butchart, S.

Contributor/s

Justification
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Sources and Credits

  1. (c) Arthur Chapman, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/32005048@N06/3004409390
  2. (c) Biopix, some rights reserved (CC BY-NC), http://www.biopix.com/photos/ANE-Larus-novaehollandiae-01881.JPG
  3. (c) Donald Hobern, some rights reserved (CC BY), http://farm5.static.flickr.com/4071/5163480871_74878888f0.jpg
  4. (c) Quartl, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Silver_Gull_Beach.JPG/460px-Silver_Gull_Beach.JPG
  5. (c) Scott Sandars, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Seagull_in_Melbourne.jpg/460px-Seagull_in_Melbourne.jpg
  6. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Chroicocephalus_novaehollandiae
  7. (c) New Guinea Birds, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/26407309
  8. (c) International Union for Conservation of Nature and Natural Resources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31109942
  9. (c) New Guinea Birds, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/26407307
  10. (c) International Union for Conservation of Nature and Natural Resources, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31109940

More Info