Conservation assessment of the Blackish Oystercatcher Haematopus ater

This assessment was difficult because there has been little study of life history or ecology, apart from limited research in the Falklands/Malvinas, where the Blackish Oystercatcher Haematopis ater is a resident. The favoured habitat is rocky beaches where limpets and mussels abound. It is infrequent on sandy beaches but small parties of immatures gather in sheltered creeks in winter. Pairs seem to remain in or near breeding territories throughout the year. In the Falklands/Malvinas it is well distributed around all coasts and is possibly more numerous on the east coast of East Falkland; it is thought to be less common than Magellanic Oystercatcher H. leucopodus. The population in 1993 was estimated to be between 12,000 and 24,000 individuals. There is some evidence for an increasing population on Chilean coasts and at Kidney Island (32 ha) in the Falklands/Malvinas. The lack of information has made it difficult to decide on priority actions, other than basic biometrical data-gathering. Some concentrated and intensive fieldwork at several localities on the coasts of Chile and Argentina will be necessary when the Wader Study Group decides that it is worthwhile to research the ecology and behaviour of this enigmatic species.