If you are in the Western Cape, and the seagull has grey wings, then with safety** you can call it a Hartlaub’s Gull. If the back is black, it’s almost certainly a Kelp Gull.
Young Hartlaub’s Gulls have a brown pattern on the feathers on the back. These patterned feathers get replaced one by one during the first year or so, and the birds then have plain grey wings like the adults.
Listen to the call of the Hartlaub’s Gull.
** The level of “safety” in the Western Cape is about 99.9%! There are only handfuls of a closely related species, the Grey-headed Gull, in the Western Cape. But what is even worse is that these two gulls interbreed. So there are some hybrids in the mix. This is what makes birding fascinating.
On the Namibian coastline there are more Hartlaub’s Gulls than Grey-headed Gulls (and quite a lot of hybrids). In the Eastern Cape most of the gulls are Grey-headed. In KwaZulu-Natal, Hartlaub’s Gull is a rare vagrant.
Mainly on the coastline, and at wetlands close to the coast.
In Namibia, they occur almost anywhere along the coast; most are in the Lüderitz area, and along the coastline from Walvis Bay Lagoon northwards to Swakopmund.
This is the easternmost record of Hartlaub’s Gull in the Virtual Museum, within the normal range. Farther east, there are two records in KwaZulu-Natal, where it is recorded from time to time. This photo was taken on the Swartkops Estuary, Algoa Bay:
And below is the northernmost record of Hartlaub’s Gull in the Virtual Museum. The bird was at the Mile 4 Saltworks, which is (well, obviously) four miles north of Swakopmund, in Namibia. This is the limit of the regular range of this species. Farther north, they occur just occasionally. This photo shows a young bird, with the juvenile feathers on the wing coverts mostly replaced by the plain grey adult feathers. There is also one brown-tipped flight feather left in the wing. The bill and legs are near the black end of the red to black continuum.
Hartlaub’s Gulls mostly breed in large colonies on the offshore islands; sometimes the colonies consist of thousands of pairs of birds:
This colony was on Robben Island in June 2014. Hartlaub’s breed in autumn and winter. Gull colonies are noisy places!
Further resources: A selection of papers
- Species text in the first bird atlas (1997) Hartlaub’s Gull Larus hartlaubii
More common names: Hartlaubse meeu (Afrikaans), Mouette de Hartlaub (French), Hartlaubmöwe (German), Gaivota de Hartlaub (Portuguese), Gaviota plateada surafricana (Spanish)
Photographic acknowledgements: Most of the photographs in this identification guide are from the BDI Virtual Museum. The photographers continue to own the copyright on these images.
Recommended citation format: Underhill LG 2023. Hartlaub’s Gull Chroicocephalus hartlaubii. Biodiversity and Development Institute. Available online at http://thebdi.org/2023/03/12/hartlaubs-gull-chroicocephalus-hartlaubii/.