As the Plover season is winding down, I am taking a little break today to share with you about a shorebird I have been documenting this past year.
Over the winter my daughter and I filmed Black Oystercatchers in Malibu, which are only found on the Pacific Coast.
Black Oystercatchers, Malibu
American Oystercatchers are the species that we see breeding and wintering along the Atlantic Coast and their range also includes both coasts of Central and South America, and Mexico.
American Oystercatchers
American and Black Oystercatchers have piercing red-rimmed yellow eyes and long three- to four-inch bills that are vivid reddish-orange bills. The bills are so super thick and strong that they are able to pry open bivalves. Oystercatchers also have adorable pink legs and funny black toenails that look more like they belong to a punk rocker. You won’t mistake these outsized and striking birds for your usual subtly hued and well-camouflaged diminutive shorebird.
I have been following three American Oystercatcher families. It’s been an incredible experience and I have learned so much about the life story of this dynamic bird. Just some of the highlights include observing what extraordinarily good parents are these shorebirds. Unlike Piping Plover chicks, which are precocial and can feed themselves within hours after hatching, Oystercatcher chicks are semi-precocial. Oystercatchers and Piping Plovers both hatch with their eyes mostly open and are covered with down. But unlike PiPls, Oystercatchers are wholly dependent on the parents for food for at least the first several months of the chick’s/fledgling’s life.
Oystercatcher parent delivering clam to chick
As the name implies, Oystercatchers eat oysters and also many types of bivalves, as well as other mollusks, crustaceans, worms, and other invertebrates that inhabit intertidal coastal zones. Mostly I observed the members of this little nesting colony eating clams and periwinkles.
When the tide is just right, the AMOY parents fly in and out of the nesting area non-stop delivering fresh caught mollusks to the very hungry chicks. Parents excise the soft fleshy meat from a bivalve in several ways. They insert their dagger like bill into a partially opened clam and quickly sever the abductor muscle. They also employ a hammering technique where they remove the mollusk (a mussel for example), from the water and position the shell just right. Once they have broken into the shell, they sever the abductor muscle.
When the chicks were very young, the parents sliced the clam into smaller bits to make it easier to swallow. Countless times I observed a chick drop its meal in the sand. The parent would then scoop up the clam bit, bring it down to the water’s edge, wash it off, and re-deliver to the waiting chick. I just thought this was so remarkable to see!
13 and 36 day old chicks letting Mom and Dad know they are hungry
Both Mom and Dad feed the chicks, at least equally, if not the male a bit more than half. As the chicks develop they eat larger and larger mollusks. It’s very funny to watch the chicks and fledglings nudge the parents to go clamming for them. They bump and rub the adult, nip its legs, and knock the parent of its perch. The adult mostly ignores the young bird until the tide is just right for foraging. The parents are very, very tolerant and I never once saw one become impatient with a youngster. When being pestered, the parent calmly shifts its position or walks away.
More to come about Oystercatchers including some footage. The story of the American Oystercatcher is one of conservation success in the making. Although these beautiful birds nest only as far north as the Boston Harbor Islands, including the rubble islands, I think it won’t be long before their range expands northward to include Cape Ann.
American Oystercatcher Range
Black Oystercatcher Range
