Lesson 9: Oystercatchers, Avocets & Stilts Flashcards
Meet North America's four large, distinctive, black-and-white shorebirds: American Oystercatcher, Black Oystercatcher, American Avocet, and Black-necked Stilt.
Which TWO species of oystercatcher are found in North America?
Image credit: Kevin Cole (left) and Rhododendrites (right)
How many species of stilt are found in North America and what are they?
How many species of avocet are found in North America and what are they?
Describe the overall physical characteristics of an oystercatcher.
List 5 features
- Large, robustly-built shorebird
- Large head and short neck
- Short, stout legs (pink)
- Long, robust bill (bright red)
- Yellow eye with red ring
Describe the overall physical characteristics of an avocet.
List 4 features
- Very large shorebird
- Long upturned bill
- Long legs and neck
- Mostly white with bold black stripes on the wings and back.
Describe the overall physical characteristics of a stilt.
List 4 features
- Large shorebird
- Extremely long, skinny legs
- Long neck and small head
- Long, thin, straight bill
Of the 10,000 bird species on Earth, stilts have the second longest legs in proportion to their body size. In first place? Flamingos!
What TWO clues can easily help you tell North America’s two oystercatcher species apart?
- Plumage: Black Oystercatcher are all black, while American Oystercatcher are black, brown, and white.
- Range: Black Oystercatcher are a western-restricted species (Pacific coast), while American Oystercatcher are eastern-restricted (Atlantic coast).
American Oystercatcher
With their bold black, brown, and-white plumage, candy-red bill, bright eyes, and stocky pink legs, you are unlikely to confuse them with any other shorebird.
The American Oystercatcher is also an eastern-restricted species limited in range to the Atlantic coastline of North America.
What birds are these?
Black Oystercatcher
Black Oystercatcher are the only large, all-black shorebird found in North America.
They are also a western-restricted species limited in range to the Pacific coastline of North America. (Compared with American Oystercatcher, which is found on the Atlantic coastline.)
This range separation means you are unlikely to ever be tasked with the challenge of telling the two species apart, even though their plumages are obviously different, which makes the job easy anyway!
What bird is this?
American Avocet
Breeding plumage
Large, unmistakable black-and-white shorebird with thin, upturned bill and bright rusty head and neck in the breeding season.
Black-necked Stilt
The incredibly long, pink legs tell us this shorebird is a stilt and since there is only one species of stilt in North America, the rest of the ID comes easily.
However, note the black that extends from the back up the back of the neck and to the head, face, and forehead. Should you ever go birding in South America, where you will find the similar-looking White-backed Stilt, noting the distribution of black on the neck and face will help you tell the two apart.
Describe the foraging technique of the oystercatchers.
They jab their long, stout bill into open bivalves (mussels, clams, and oysters) like a knife, quickly severing the ligaments that connect the top and bottom shells, allowing them to get at the animal’s nutritious insides.
Describe the foraging technique of the Black-necked Stilt.
They wade through shallow water, picking food morsels out of the water column, sometimes completely submerging their heads or swishing their bills back and forth.
Describe the foraging technique of the American Avocet.
They swipe or “scythe” their curved bills from side-to-side through the water, detecting food by touch, walking slowly as they forage.
They do not probe like many other shorebirds.
What bird is this?
American Avocet
Non-breeding plumage
This long-legged shorebird has a distinctive long, thin bill that curves upward, as well as bold black-and-white patterning on the back and sides. Females and males look mostly alike, except that the female’s bill is shorter and curves a little more than the male’s.
What bird is this?
Black Oystercatcher
Black Oystercatcher use their robust red bills to force bivalve mollusks open to get to the flesh inside. Because of their diet, they are strictly coastal marine birds that never venture inland.
American Oystercatcher
American Oystercatcher have an eastern-restricted range in North America so you are very unlikely to ever see one on the west coast of the continent. (Only very rarely in the southernmost parts of California.)
Instead, on the west coast, you will find Black Oystercatcher, which, with its all-dark plumage, looks remarkably different.
What birds are these?
Try also to identifying the two Tringas in the picture!
Photo by Charles J. Sharp
Black-necked Stilt
and Solitary Sandpiper
These incredibly tall, black-and-white birds are recognizable based on their shape alone. But if, at a glance, you ever confused them with an avocet, look for their:
- Pink legs, not gray
- Black on necks, heads, and faces, not white
- Total lack of rufous coloring
- Very long legs that trail far behind them in flight
- All black wings (above and below) in flight, without a wing bar.
Black-necked Stilt
Note the all-black wings, both above and below (no wing stripe) and the long, pink legs. Another thing to pay attention to is how vocal and noisy Black-necked Stilt are when flushed and in flight!
American Oystercatcher
American Oystercatcher show very bold white wingbars and a white rump in flight. The stout, bright red bill is diagnostic of an oystercatcher and is usually visible in flight.
What bird is this?
American Avocet
Non-breeding plumage
In non-breeding plumage American Avocet lose their rich reddish plumage. Still, their size and all black-and-white plumage are striking!
They use their thin upturned bill to “scythe” the water for morsels in the water column.
What bird is this?
Black Oystercatcher
Juvenile
Unmistakable shorebird of the Pacific coast. All black, red bill, and light pink legs. This individual is transitioning to adulthood and we can tell this from the color of the bill, which is yet to fully develop to red, as well as the light scalloping of the feather edges on its flanks.
