The Canary Islands oystercatcher, Canarian oystercatcher, or Canarian black oystercatcher (Haematopus meadewaldoi), was a shorebird of uncertain taxonomy endemic to Fuerteventura, Lanzarote, and their offshore islets (Islote de Lobos and the Chinijo Archipelago) in the Canary Islands in Spain. It is now considered to be extinct.
The Canary Islands oystercatcher has had a complicated taxonomic history. Though it was long known to naturalists, it was considered a mere local population or subspecies of the African oystercatcher (Haematopus moquini) until 1913; these two were at the time occasionally lumped as subspecies of the Eurasian oystercatcher (Haematopus ostralegus). Hockey (1982) concluded that the Canary Islands oystercatcher was actually a full species, distinct from the African oystercatcher. However, DNA analyses conducted in 2018 and published in 2019 concluded that the Canary Islands oystercatcher was most likely a subspecies of the common Eurasian oystercatcher.
Taxonomy
The Canary Islands oystercatcher was long considered a population of the African oystercatcher until 1913, when David Armitage Bannerman identified it as the unique subspecies H. m. meadewaldoi. A study in 1982, however, found the Canary Islands oystercatcher to be distinct enough from the African oystercatcher to be upgraded to be its own species.
In 2018, a genetic study of the Canary Islands oystercatcher's mitogenome found it to be genetically nearly identical to the Eurasian oystercatcher, with its genetic differentiation falling well within the range in variation observed in the Eurasian oystercatcher. It has thus been proposed that H. meadewaldoi be reclassified as either a melanistic color morph or subspecies of the Eurasian oystercatcher. Ornithological committees such as the International Ornithological Congress and BirdLife International need to decide whether or not to downgrade the species.
Description
The Canary Islands oystercatcher was of similar size as its relatives, the African and Eurasian oystercatchers, or about ; comparing with the non-migratory African species, it probably weighed between in life, with females being slightly heavier. Its bill was some long in males and markedly longer (around ) in females; the tarsus measured around , and the wings were around long, with males possibly at the upper range of that size.
Its appearance was extremely similar to the African species, to the extent that even hand-held specimens can hardly be told apart except by direct comparison or measurements. Its bill was longer and its wings were shorter than in the African species, which is not known to occur north of Lobito, Angola however, at least in modern times. H. meadewaldoi had a glossy black coloration overall save for the whitish underwing bases of the primary remiges' inner webs, but this may have not been present in worn plumage which also was duller. Its bill, laterally compressed and with a blunt, lighter tip, and a narrow naked ring around the red eye were reddish orange, and the legs and feet were dark pink with ivory-colored nails. As usual in oystercatchers, it had no hallux and the second and third toes were connected by a small web.
The sexes did not differ in color; juvenile birds are unknown but probably had duller bare parts and some greyish-buff fringes to the feathers. The coloration of downy young is likewise unknown; these are generally brownish-grey above with dark striping to provide camouflage against predators such as gulls; considering the dark lava rock habitat of this species, they were probably fairly dark overall and had a dusky belly.
Habits
The Canary Islands oystercatcher was apparently an all-year resident, and seems to have never bred or even strayed outside the eastern Canaries at least in historic times. Information about its ecology are scant and usually second-hand or inferred from circumstantial information. However, even though conjectural, these informations are consistent as the biology of oystercatchers is not very variable and the species was a conspicuous bird well known to locals. It was called cuervo marino ("sea raven") on Fuerteventura, grajo de mar ("sea chough") on Lanzarote, and corvino ("little raven") on Graciosa. In addition, the local name lapero ("limpet-eater") was also used, possibly on Alegranza.