By Obiabin Onukwugha
Oystercatchers are a group of waders forming the family Haematopodidae. They are found on coasts worldwide apart from the polar regions and some tropical regions of Africa and South East Asia.
There are 12 species of oystercatcher in the world, all of which look very similar, being either pied or plain black, with a red bill and pink legs.
Their name is derived from the fact that they mostly prey on oysters. Some species of oystercatcher became extinct in the 20th century.
The diet of oystercatchers varies with location. Species occurring inland feed on earthworms and insect larvae. The diet of coastal oystercatchers is more varied, although dependent upon coast type; on estuaries, bivalves, gastropods and polychaete worms are the most important part of the diet, whereas rocky shore oystercatchers prey upon limpets, mussels, gastropods, and chitons. Other prey items include echinoderms, fish, and crabs.
Individuals have two main techniques for handling their difficult prey. Some which have shorter, blunter bills, specialise in hammering the prey through the shell, while others, with longer, pointier bills, prise the two shells apart.
The longevity record for an oystercatcher stands at 40 years, one month and two days.
These creatures have two important effects on the dynamics of rocky shores. First, their guano fuels primary production. Second, oystercatchers that aggregate on the islands prey on limpets.
Oystercatchers are at a risk as climate change is said to have negative impacts on their populations.
Loss of breeding, wintering, and migration habitats are recognized as threats to oystercatcher populations, because of their high degree of habitat specialization.
The oystercatcher is also linked to traditional belief and folklore as its whirling and turning is reputed to have its origins in its dismay at being cheated out of the ability to swim by a seagull who stole its webbed feet.
