All about oystercatcher
Despite its name, the main diet of the oystercatcher rarely involves oysters in the UK. They tend to eat juicy worms, small crustaceans, and bivalves such as cockles and mussels.
Oystercatchers have two main techniques for breaking open their robust prey. Some individuals have shorter, blunter bills, and specialise in hammering through the shell to eat their prey inside. Others, with longer, pointier bills, prise the two halves of the shell apart.
Interestingly it’s their behaviour that changes their bill shape – rather than the bill shape dictating their behaviour. Oystercatcher bills grow by almost half a millimetre a day – that’s 3 times faster than our fingernails. This means they can change their bill shape very quickly, from short and blunt to long and pointy, in less than 2 weeks if they need to adapt to changes in food supplies.
They spend much of their time feeding on the coast, but at hightide you might spot them on nearby grassland.
They are easily spotted on UK shores, and increasingly inland too, which can give the impression they are doing really well as a species but they are actually suffering a worrying decline in Europe. The UK holds over a third of the European population of oystercatchers (at certain times of year) so these coastlines are a real stronghold for the species.
Oystercatcher parents
You can sometimes see young oystercatchers being fed by their parents months after they have fledged.
Young oystercatchers are looked after by their parents for much longer than most other wading birds. The offspring of other waders can usually feed themselves soon after hatching (known as ‘precocial’). Oystercatcher chicks on the other hand, are what is known as ‘semi-precocial’ and this means they largely rely on their parent to bring food to them.⠀
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Since individual oystercatchers have different feeding techniques to specialise in feeding on different food types, young birds need to learn these techniques, and it is thought that the young of mussel-feeding oystercatchers have the longest apprenticeship of them all – up to 26 weeks.⠀