African oystercatcher

Description

The African oystercatcher is a large, noisy wader, with completely black plumage, red legs and a strong broad red bill. The sexes are similar in appearance, however, females are larger and have a slightly longer beak than males. Juveniles have soft grey plumage and do not express the characteristic red legs and beak until after they fledged. The call is a distinctive loud piping, very similar to Eurasian oystercatchers. As the Eurasian oystercatcher is a migratory species they only occur as a vagrant in southern Africa, and its black-and-white plumage makes confusion impossible.

Average measurements

Body Length: 42 –

Wingspan: 80 and

Mass: ♂ 665 g ♀ 730 g

Tarsus: 50.6 to

Culmen: 57.7 to

Distribution and habitat

The African oystercatcher is native to the mainland coasts and offshore islands of Southern Africa. Its breeding range extends from Lüderitz, Namibia to Mazeppa Bay, Eastern Cape, South Africa, with dispersal in winter north to southern Angola and southern Mozambique. There are estimated to be over 6,000 adult birds in total. There is one record of a vagrant from Gambia, a specimen from 1938 in the British Museum which proved to be H. moquini on genetic analysis after previously being considered unidentified or possibly a Canary Islands oystercatcher H. meadewaldoi.

Typically sedentary African oystercatchers rarely leave their territories, which include a nesting site and feeding grounds. These will usually be located on or near rocky shores where they can feed.

Ecology

Feeding

African oystercatchers predominantly feed on molluscs such as mussels and limpets, although they are known to also feed on polychaetes, insects and potentially even fish. They are adapted to pry open mussels and loosen limpets off the rocks but have been recorded picking through sand to locate other food items.

Breeding

The nest is a bare scrape on pebbles, sand or shingle within about 30 m of the high-water mark. On rock ledges there may be a rim of shells to keep the eggs in place. The female generally lays two eggs, but there may be one or three, which are incubated by both adults. The incubation period varies between 27 and 39 days and the young take a further 38 or so days to fledge. Breeding success is greater on offshore islands where there are few predators and less disturbance than mainland sites.

The eggs average about 65 mm in length, ranging from 45 to, and have a breadth of 41 mm, ranging from 34 to.

Longevity and mortality

The lifespan of an African oystercatcher is about 35 years, of which they are known to pair up for 25 years. Although adults are rarely predated, most mainland egg and chick fatalities are due to disturbance by people, off-road vehicles, dog attacks and predation by the kelp gull (Larus dominicanus) and other avian predators. Offshore pairs experience similar avian predation although most chicks perish due to starvation.

Status

As of December 2017 the global IUCN assessment of the African oystercatcher's status is "Least Concern". The population trend seems to be upward as the local community becomes more involved in adopting conservation measures. In South Africa, the species has also been downlisted to Least Concern. A long-term program by the South African Ringing Scheme is tracking the dispersal of ringed birds to keep conservation assessments in South Africa and Namibia up to date.

Gallery

Image:African Black Oystercatcher RWD2.jpg|Plettenberg Bay, South Africa Image:Haematopus moquini P1040458.JPG |Feeding on the rocky shore Image:African Black Oystercatcher, (Haematopus moquini) standing on the sand.jpg|Taken in South Africa Image:Three African Black Oystercatchers (Haematopus moquini) in flight.jpg|Three in flight Image:African Black Oystercatcher RWD1.jpg|at De Hoop, South Africa Image:Oystercatcher nest three eggs.jpg|Three egg clutch Image:African Black Oystercatcher chick.jpg|African oystercatcher chick Image:African Black Oystercatcher shading eggs.jpg|African oystercatcher shading eggs Image:African black oystercatchers.JPG|A pair in flight Image:African Black Oystercatcher 01 (3545455502).jpg|African oystercatcher 01 Image:African Black Oystercatcher SMTC.jpg|African oystercatcher Image:Haematopus moquini.jpg|Haematopus moquini Image:Haematopus moquini P1040460.JPG|Haematopus moquini Image:Haematopus moquini portrait.png|Haematopus moquini portrait Image:Haematopus moquini young.png|Haematopus moquini young Image:Haematopus moquini P1040465.JPG|Haematopus moquini

References

References

1. BirdLife International. (2017). "''Haematopus moquini''".
2. Parzudaki, Émile (1856). Catalogue des oiseaux d'Europe offerts, en 1856, aux ornithologistes. Paris: E. Parzudaki.
3. Verzeichniss der Doubletten des zoologischer Museums hiesiger Königl.Universität...nebst Beschreibung vieler bisher unbekannter Arten von Säugethieren, Vögeln, Amphibien und Fischen..., p.73.
4. The Genera of Birds, 1844-49, Pt.42, Haematopodinae (Dec.), no.2. bound vol.3, p. 547.
5. Die vollständigste Naturgeschichte der Sumpfvögel:Aves Grallatores. (= Novitiae ad Synopsin Avium...II.Grallatories (III Rasores) No.: V, pl.168, figs.1042-43.
6. Nomenclator avium Musei Zoologici Berolinensis.Namenverzeichniss, p.93. (Kaffernland). Not Haematopus unicolor Wagler,1832.
7. Nomenclator Musei Heineani Ornithologici, p.337.
8. Checklist of Birds of the World, 2, p.233.
9. Hockey, P. A. R.. (2005). "Roberts birds of southern Africa". Trustees of the John Voelcker Bird Book Fund.
10. Parzudaki, Émile. (1856). "Catalogue des oiseaux d'Europe offerts, en 1856, aux ornithologistes". E. Parzudaki.
11. Senfeld, Tereza. (2020). "Taxonomic status of the extinct Canary Islands Oystercatcher ''Haematopus meadewaldoi''". Ibis.
12. Ryan, P. G.. (2008). "African Black Oystercatchers feeding in a terrestrial habitat". Ostrich.
13. Paijmans, D. M.. (2013). "Piscivory in the African Black Oystercatcher". Promerops.
14. "Species factsheet: African Oystercatcher ''Haematopus moquini''". BirdLife International.
15. "The Eskom red data book of birds of South Africa, Lesotho and Swaziland". BirdLife South Africa.
16. "Oystercatcher Conservation Programme (OCP)". Percy Fitzpatrick Institute - University of Cape Town.