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 may be small, but it is not believed to 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). Therefore, the species is now listed as Least Concern.
Population genetics suggest that there has been a low historical population size (Bray and Hockey 2015). The population is now estimated at 6,670 individuals (Underhill 2014), roughly equivalent to 4,450 mature individuals.
The population is suspected to be increasing thanks to improved habitat management on near-shore islands, with a c.45% increase between 1979/1980 and the early 2000s (Underhill 2014, Loewenthal et al. 2015). There have been some local declines, but it appears possible that in a large number of cases these declines may be a result of individuals moving to adjacent habitats after a site has experienced some degradation (in 72% of cases where a site showed a decline, the adjacent areas showed a population increase) (Loewenthal et al. 2015).
Haematopus moquini has a coastal breeding range which stretches from Lüderitz, Namibia, to Mazeppa Bay, Eastern Cape, South Africa. The total population is estimated to number 6,670 individuals (Underhill 2014, Loewenthal et al. 2015), with about half occurring along the Western Cape (South Africa) coastline, half of these on its near-shore islands.
Behaviour Adults of this species are mostly sedentary, although some seasonal movement occurs between breeding and non-breeding habitats (Hockey et al. 2005), within a 15km range (Urban et al. 1986). Breeding occurs from September to April, with a peak from November to February (del Hoyo et al. 1996, Hockey et al. 2005). It breeds slightly later in Namibia than in South Africa (del Hoyo et al. 1996, Hockey et al. 2005). The start and duration of egg-laying is affected by predation risk and weather conditions, including unpredictable tidal inundation (Calf and Underhill 2005, Tjørve and Underhill 2008). Juveniles disperse from their natal area, but dispersal distance shows a great range, from only a few kilometres to >2,000km (Rao et al. 2014). These return to their natal area after 2-3 years (Hockey et al. 2005, Scott et al. 2011). The species breeds and forages solitarily (Urban et al. 1986, Hockey et al. 2005), but roosts communally in groups of up to 200 in the non-breeding season (Urban et al. 1986, Hockey et al. 2005). Habitat Breeding Offshore islands and sandy beaches are favoured as breeding habitats (Hockey et al. 2005). It rarely breeds on mainland rocky shores (Urban et al. 1986, Hockey et al. 2005), although this has been recorded at De Hoop Nature Reserve in the southern Cape (Scott et al. 2011, 2012). Non-breeding The species forages exclusively in the intertidal zone (Urban et al. 1986, Hockey et al. 2005) and is found on mainland rocky and sandy shores during the non-breeding season, being less frequent in estuaries, lagoons and coastal pans (del Hoyo et al. 1996, Hockey et al. 2005). It tends to roost on promontaries with good all-round visibility (Hockey et al. 2005). Nurseries occur in both sheltered bays and open rocky shores (Hockey et al. 2005). Diet Its diet includes primarily bivalves such as limpets and mussels, but also polychaetes, whelks and crustaceans (Urban et al. 1986, del Hoyo et al. 1996, Hockey et al. 2005, Scott et al. 2012). Breeding site The nest is a scrape in sand where possible, but on rocky subtrata shells are built up to form a lip (Urban et al. 1986, del Hoyo et al. 1996, Hockey et al. 2005), or eggs are laid on bare rock (del Hoyo et al. 1996, Hockey et al. 2005). The nest is usually situated within 30m of the high water mark (Hockey et al. 2005, Calf and Underhill 2005), often beside a disruptive object such as a rock or clumps of kelp (Hockey et al. 2005, Jeffery and Scott 2005). The clutch-size ranges from one to three eggs, but is usually two. The incubation period is 27-39 days, followed by a fledging period of 35-40 days; pairs rear one or two chicks. Fledging success is 0.3-0.6 young per pair per year on predator-free offshore islands, but is usually lower on the mainland (but 0.7-0.9 has been recorded at De Hoop Nature Reserve on the mainland [Scott et al. 2011]). There is evidence that breeding productivity has increased on the west coast since 1980, following the invasion of the Mediterranean mussel Mytilus galloprovincialis. Age of first breeding is three years in females, and probably four years in males. The species is known to live for over 18 years (del Hoyo et al. 1996).
The peak of the breeding season coincides with peak coastal recreational activities and the resulting disturbance reduces breeding success (Leseberg et al. 2005). Off-road vehicles are a particular problem, as they churn up beaches, run over nests and crush eggs, and kill young hiding in vehicle tracks. In addition, people on beaches, and mixed shores, used for breeding can keep adults off nests for extended periods, overheating eggs and killing embryos, and predation of eggs and chicks by domestic dogs can be a problem (Leseberg et al. 2005). Disturbance also leads to the predation of eggs and chicks by Kelp Gulls Larus dominicanus (Jeffery and Scott 2005, Scott et al. 2011). On sections of the coastline undisturbed by humans, natural predators (e.g. mongoose) take many nests. The mainland is likely to prove a population sink for surplus birds from near-shore islands, with breeding productivity too low to sustain coastal populations. Coastal development is thought to have caused declines in some areas (del Hoyo et al. 1996). The c.30% of the total population that is found on offshore islands is threatened by the introduction of mammalian predators (del Hoyo et al. 1996).
Conservation Actions Underway
On most near-shore islands, population sizes have been stable or increased recently due to either improved management, e.g. the cessation of guano-scraping during the 1980s, and/or a change in diet from indigenous limpets and mussels to invasive mussels such as Mytilus galloprovincialis (e.g. at Robben Island, South Africa) (Calf and Underhill 2002). Recreational vehicles have been banned from the Overberg coast since February 2002 (Jeffery and Scott 2005), and this has been associated with a significant increase in numbers of adult oystercatchers at De Hoop Nature Reserve from 1994 to 1998 (Scott et al. 2011). The national Oystercatcher Conservation Programme (OCP) has been raising public awareness concerning the species and its needs, and has been generating local community involvement it its conservation (Jeffery and Scott 2005).
42-45cm. All dark oystercatcher with fully black upperparts, orange bill and eye-ring, red eye and pinkish-red legs. Similar spp. Very similar to other black oystercatchers, but range does not overlap. Darker upperparts than New World species and bill much shorter than Australasian species. The Extinct Canary Island Oystercatcher H. meadewaldoi had shorter wings and a longer bill than H. moquini.
Text account compilers
Butchart, S., Robertson, P., Taylor, J., Pilgrim, J., Ashpole, J, Martin, R, Westrip, J., O'Brien, A.
Simmons, R., Dodman, T., Scott, A., Paijmans, D.
BirdLife International (2021) Species factsheet: Haematopus moquini. Downloaded from http://www.birdlife.org on 28/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/10/2021.