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 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.
The overall population trend is increasing, although some populations have unknown trends (Delany and Scott 2006).
This species is found in South America, breeding from south-central Chile round Tierra del Fuego to Argentina and Uruguay including the Falkland Islands (Islas Malvinas), and wintering up to the coasts of north Chile and central Brazil (del Hoyo et al. 1996).
This species is found on sea coasts, rivers, lakes and marshes, and will frequent sewage outfalls, slaughter-houses, harbours and fields. It is largely insectivorous, but in Chile breeding birds feed mainly on fish. Breeding is sometimes solitary, but usually in colonies of 5-50 nests and occaisionally over 500 nests. It breeds mainly on freshwater or alkaline lakes, but also on rocky peninsulas or high on shingle beachges (del Hoyo et al. 1996).
The population is increasing and it is not currently facing any recorded threats.
Text account compilers
Butchart, S., Calvert, R., Ekstrom, J.
BirdLife International (2019) Species factsheet: Larus maculipennis. Downloaded from http://www.birdlife.org on 20/04/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 20/04/2019.