Waders, gulls and terns | Charadriiformes

Families in this order

• Thick-knees and stone-curlews | Burhinidae1 speciesLarge yellow eyes and a short, heavy bill with a swollen tip: these are birds of dusk and darkness that spend the day motionless on the ground, where their sandy, streaked plumage makes them hard to separate from the soil. The legs are long, with a conspicuously thickened joint halfway down that gives the group its name, and carry three short, thick toes with no hind toe. They live on dry, stony or sandy open country, often far from water, taking beetles, worms, lizards and mice on foot. The nest is a scrape with two eggs, and as evening falls a far-carrying, wailing call gives them away.
• Stilts and avocets | Recurvirostridae2 speciesExceptionally long legs and a thin, flexible bill, either straight or curved upwards: waders that walk belly-deep into shallow, often brackish or saline water. The front toes are webbed, so they can also feed while swimming; one build picks prey one at a time from the surface, the other sweeps the half-opened bill sideways through the water and feels what passes between the mandibles. In every species the plumage is a crisp pattern of black and white that changes little between summer and winter. They breed in loose colonies on bare ground beside water, lay three or four eggs in a scrape, and drive intruders off with loud calls and diving attacks.
• Oystercatchers | Haematopodidae2 speciesA long, heavy, laterally flattened orange-red bill is the tool of this family: it is driven like a chisel between the shells of a bivalve or used like a hammer on the shell itself, and it wears down so fast in the work that it grows continuously. With it go short, sturdy legs with three toes, a red eye-ring, and a plumage that is either black and white or wholly black, alike in both sexes. Unlike almost all other waders, the chicks do not feed themselves: opening shellfish takes so much practice that the parents go on feeding them for months. The clutch is two or three eggs in a scrape, and the birds announce themselves in loud, piercing piping displays, small groups walking about with the neck drawn in and the bill pointed down.
• Plovers and lapwings | Charadriidae11 speciesCompact birds with a large head, short neck and a short bill thickened towards the tip, made for picking prey from the surface rather than probing into the ground. They feed with a characteristic run, stop and peck pattern, also in the dark, and some species patter one foot on wet ground to bring prey to the surface. Black bands across breast and head break up the outline on bare ground. The clutch usually consists of three or four pear-shaped eggs in a scrape on bare sand, gravel or short-grazed grassland; when danger threatens the parents lead an intruder away with a feigned broken wing. In Mexico and Central America some species are resident, such as the Killdeer and the plovers of sandy beaches and salt flats, but most are migrants from the far north that winter here or pass through, with long, pointed wings for the flight from the tundra. The Southern Lapwing is a newcomer that has been spreading north from Panama in recent decades; it carries a sharp spur at the bend of the wing and noisily attacks anyone who approaches its nest.
• Jacanas | Jacanidae2 speciesA small family of eight species in tropical freshwater marshes worldwide. In Mexico and Central America Northern Jacana occurs from Mexico to western Panama, and in Panama Wattled Jacana as well. Their best-known feature is the extremely long toes and claws, which spread their weight over a large area so that they can walk on water lilies, water hyacinth and other floating vegetation. Both species have a fleshy frontal shield, yellow in Northern Jacana and red with wattles in Wattled Jacana, a sharp spur at the bend of the wing and yellow-green flight feathers that show only in flight. The flight is short and fluttering, with dangling legs. They eat insects, snails and other invertebrates picked from leaves or from under turned-up leaf edges. Sex roles are reversed. The female is clearly larger than the male, defends a territory holding several males, and lays a clutch for each of them. The male alone incubates the four glossy, black-scrawled eggs on a floating nest and alone cares for the chicks, which he takes under his wings when danger threatens. The calls are rasping, cackling and chattering. Their closest relatives are the painted-snipes.
• Sandpipers and allies | Scolopacidae32 speciesThe bill is not only long and sensitive but mobile: the tip of the upper mandible alone can be raised, so the bird can seize a worm deep in the mud without opening the bill along its whole length. Length and curvature differ greatly from species to species, so that birds feeding side by side on the same flat reach different depths and different prey. The plumage is grey-brown and finely marked, and changes completely twice a year: a conspicuous breeding dress and a plain winter one. Four pear-shaped eggs in a scrape, chicks that find their own food from the first day, and outside the breeding season large flocks that wheel as one over the tidal flats.
• Jaegers and skuas | Stercorariidae4 speciesGull-like in shape, but with a heavier chest, a strongly hooked bill made up of separate horny plates with a fleshy cere over the base, and sharp, curved claws on webbed feet; females are larger than males. The plumage is brown or grey-brown, in several species with a pale and a dark morph side by side, and a white patch at the base of the primaries flashes in flight. They live largely on what other seabirds catch, forcing gulls and terns in long chases to give up their prey, and they also take eggs, chicks and carrion. They breed on open tundra and moorland, lay two eggs in a scrape and defend it with diving attacks; the rest of the year is spent at sea.
• Auks, puffins and murres | Alcidae5 speciesCompact, short-necked seabirds, dark above and white below, with small narrow wings used both for flying and for rowing underwater. That double duty is a compromise: wing loading is high, take-off is laboured and the flight is fast and whirring with continuous beats, while legs set far back leave them upright but awkward on land. They breed in colonies on cliff ledges, in burrows and in crevices, laying a single egg with no nest material — strongly pear-shaped in the species that use bare ledges. After breeding most species shed all their flight feathers at once and cannot fly for some weeks.
• Skimmers, noddies, terns and gulls | Laridae39 speciesThree fully webbed front toes and a small, raised hind toe: these birds can rest on the water, and salt glands above the eyes let them drink sea water as well. Two builds stand side by side within the family: heavier birds with a stout, slightly hooked bill that will eat almost anything they can get hold of, and slighter birds with a thin, pointed bill held downwards while hovering, before they drop into the water. They nest almost always in ground colonies, with one to three blotched eggs; the downy chicks stay at the nest and are fed by both parents, unlike the self-feeding young of the waders. Most species moult twice a year and show a different head pattern in winter, and in the largest species it takes two to four years before the adult plumage is complete.