A flock of oystercatchers performing an aerial piping display as part of a territorial display our courtship.
Nesting begins with the formation of a pair through courtship and the defense of a territory. Oystercatchers court on the ground by cocking their heads down, piping loudly, and running together.
Both sexes scratch out small depressions called scrapes, but the male scrapes more than the female. Scraping can go on for several weeks. The female will pick one lucky scrape and lay her eggs in it.
Oystercatchers mate multiple times during courtship and sometimes into early egg-laying.
In the simple scrape, two to three eggs are laid. Some oystercatchers decorate the edge of the scrape with shells, small sticks, or other objects.
Incubating is essential. The eggs must be kept at the right temperature: if they are too cold, the embryo inside develops too slowly, and if they overheat in the hot sun the embryo inside can die.
The dedicated parents wear a path to the nest.
Eggs hatch in 24-29 days. When the chick first breaks through the eggshell, the egg is “pipped” and the chick will emerge in less than 24 hours.
Upon hatching, the chicks are wet, but they dry in a few hours and can stand and walk on the same day. However, they stay near the nest for the first few days.
For the first week or so, chicks are small and downy and require their parents’ help to protect them from the elements. Overheating is a real danger for a young chick, as is hypothermia during a rainstorm.
As small as they are, they are also easy prey for many animals including gulls, so the parents chase potential predators away by flying at them and sometimes even pecking them.
As the chicks get bigger, they find their own hiding places, and they use their brown and black plumage to camouflage themselves from predators.
Foraging with Chicks
The parents accompany the chicks to the water’s edge where they might forage for coquinas, but the parents mostly rely on larger prey, like oysters, to feed the chicks.
The chicks can be quite persistent, bumping their parents over and over, when they want to be fed.
The parents may bring back the meat only, or the entire shellfish, which they open in front of the chicks. Once they can fly at about 30 days of age, the chicks accompany the parents to foraging areas. However, it will take another 60 days before their bills are big enough for the chicks to be totally independent of its parents.
Finally a fledgling’s bill grows big enough and it’s learned all it can from its parents. It is now a fledgling and ready to take care of itself.
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