Justification of Red List Category
This species has an extremely 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 extremely 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.
The population is estimated to number 3,300,000-4,300,000 individuals.
The overall population trend is increasing, although some populations have unknown trends (Delany and Scott 2006).
The Kelp Gull breeds on coasts and islands through much of the southern hemisphere. It is found on a number of subantarctic islands, on the Antarctic peninsula, on the southern coast of Australia and all of New Zealand, on the southern cost of Africa and Madagascar, and on the coast of South America as far north as Ecuador and southern Brazil (del Hoyo et al. 1996).
Behaviour Although this species is largely sedentary some southern populations migrate north after the breeding season (del Hoyo et al. 1996). The species breeds between late-September and January in colonies of up to several hundred pairs (occasionally nesting solitarily and remains gregarious outside of the breeding season (del Hoyo et al. 1996, Hockey et al. 2005). Habitat It inhabits sheltered coastal harbours, bays, inlets, estuaries, beaches and rocky shores, usually foraging within 10 km of the shore but also following fishing boats beyond the continental shelf (Higgins and Davies 1996, del Hoyo et al. 1996). It may forage and roost in near-coastal inland habitats including lagoons, lakes, swampy basins, rivers, streams, reservoirs, pastures, cultivated land, tussock grassland, scrubland and cleared areas in pine plantations (Higgins and Davies 1996, del Hoyo et al. 1996, Hockey et al. 2005). It often also forages around abattoirs, fish- or seafood-factories and at sewage outfalls (del Hoyo et al. 1996). Breeding habitats include headlands; sea cliffs; rocky outcrops; stacks; offshore islands; reefs; peninsulas; mudflats; sandbanks; the roofs of coastal buildings; salt and sewage works; guano platforms; shipwrecks; above the high water mark on low sandy, pebbly or rocky beaches; and spits or islands in estuaries and lagoons (Higgins and Davies 1996, del Hoyo et al. 1996, Hockey et al. 2005). Locally (e.g. in New Zealand) it may also breed inland on flat rocky mountaintops near permanent water (Higgins and Davies 1996).Diet Its diet consists of molluscs (e.g. mussels, cuttlefish Sepia spp. and terrestrial snails), echinoderms, sponges, arthropods (e.g. swarming termites, crabs, isopods, amphipods), macrozooplankton, fish, worms, reptiles (e.g. snakes), amphibians (e.g. frogs), small mammals, birds and berries (del Hoyo et al. 1996, Hockey et al. 2005). The species also scavenges refuse, sewage and carrion (del Hoyo et al. 1996, Hockey et al. 2005). Breeding The nest is a bulky structure of dried plants or seaweed placed on bare rock, sand or mud substrates in well-vegetated sites (with grasses, sedge, rushes and other herbaceous plants) at the base of bushes, trees, rocks, walls or other vertical structures (Higgins and Davies 1996, del Hoyo et al. 1996). Management information Attaching high-visibility plastic cones to trawler warp cables can significantly reduce the mortality and bycatch of this species due to trawler fisheries (Gonzalez-Zevallos et al. 2007).
The species is potentially threatened by future marine oil spills (Parsons and Underhill 2005), and is susceptible to avian cholera (Hockey et al. 2005, Leotta et al. 2006) and avian botulism (Blaker 1967, Hockey et al. 2005) so may be threatened by future outbreaks of these diseases. The species also suffers mortality from interactions with trawler warp cables (Argentina) (Gonzalez-Zevallos et al. 2007). However, none of these threats are thought to pose a genuine threat to the population at present.
Text account compilers
Calvert, R., Ekstrom, J., Butchart, S., Bennett, S., Malpas, L., Stuart, A.
BirdLife International (2019) Species factsheet: Larus dominicanus. Downloaded from http://www.birdlife.org on 07/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 07/12/2019.