Waders, gulls and terns | Charadriiformes

Families in this order

• Plovers and allies | CharadriiLarge eyes are the mark of the group: these birds find their food by sight and take it from the surface, which gives them their stop-start gait - run, halt, peck, run again. Bills vary widely within the group, from short and blunt to long and chisel-shaped, but the foot is the same throughout: three toes forward and a hind toe that is small or missing. The chicks are only guarded and brooded; from their first day they gather their own food. Anyone who comes too close to the nest is led away by a parent that stumbles ahead of him calling loudly, as though its wing were broken.
• Stilts and avocets | Recurvirostridae2 speciesFeeding is done wading in shallow, often saline or alkaline water. In the species with an upturned bill it goes by touch: the bill is swept sideways through the top layer of silt in a steady rhythm, the curved part sliding flat along the bottom; species with a straight bill instead pick deliberately from the water surface and from water plants. The legs are long enough to wade deeper than other shorebirds can manage, and where the bottom falls away the bird swims and tips forward to reach its food. Midge larvae, brine flies, small crustaceans and seeds make up the bulk of the diet. The nest is a scrape close to the waterline, often in loose groups; if the water rises, material is pushed in under the eggs and the rim is built up. At any threat the whole group takes to the air with loud, sharp yelping and keeps diving over the intruder, while a parent limps along the ground to draw attention away from the chicks.
• Oystercatchers | Haematopodidae2 speciesThe bill is flattened sideways into a chisel and is used in two ways: some birds push it between the valves of a shell that is still gaping and cut through the closing muscle, others hammer the shell open against a stone or at its weaker side. Which of the two a bird uses is learned from its parents; the bill wears to that use and changes shape within weeks if the bird switches. On grassland and arable fields earthworms are pulled from the ground as well. Unlike almost all other shorebirds, the chicks do not find their own food: the parents carry it to them for months, until well after the young can fly, because opening shellfish takes too much practice. The nest is a scrape above the tideline, with two or three eggs. Neighbours and intruders are met with a loud, accelerating piping, the birds walking side by side along the shore with necks bent and bills pointed straight down.
• Plovers and lapwings | Charadriidae13 speciesThe bill is short, straight and relatively thick, suited to hunting by sight: the bird runs across exposed mud or grass, stops abruptly and snatches prey from the surface, rather than probing blindly as many other shorebirds do. The large eyes point to a habit of foraging at dusk and after dark, when moonlight or artificial lighting is enough to hunt by. The clutch is usually four pear-shaped eggs laid points inward in a bare scrape on open ground; their mottled pattern lets them vanish against gravel or bare earth. When threatened, a parent will often fake a broken wing to lure predators away from the nest, while the downy chicks flatten themselves to the ground and freeze.
• Sandpipers and snipes | ScolopaciA long bill with pressure sensors in the tip: these birds locate their prey by touch, deep in mud or damp ground and without ever seeing it, so they feed as well in the dark as by day. The plumage is brown and finely streaked or mottled, and the eyes sit high and far back in the head, so that a probing bird keeps watch above and behind it. Care of the eggs is divided in strikingly different ways within the group: in a number of species the male incubates alone while the female lays in quick succession for several partners. Song in the ordinary sense is usually absent; over the breeding grounds they make sound with their tail or wing feathers, in display flights that can last all night.
• Jacanas | Jacanidae1 speciesThe toes and claws are outlandishly long — the straight hind claw can be longer than the toe itself — so that the bird's weight is spread over a wide area and it can walk across floating lily and reedmace leaves without sinking through. It feeds on foot, picking between the leaves and off the water surface: insects, snails, small fish and seeds, at times turning a leaf over with the bill to see what lies beneath. A sharp spur at the bend of the wing is used for striking in territorial fights, and part of the family carries a bare fleshy lobe on the forehead. The roles are reversed: the female is much the larger, holds a territory containing several males and lays a clutch for each of them. The male then builds the nest alone — a thin mat of stems on floating leaves, often sodden — incubates the glossy eggs scrawled all over with dark lines, and raises the young by himself; at any threat he clamps the chicks under his wings and carries them off with their legs dangling.
• Sandpipers and allies | Scolopacidae54 speciesThis is a family of touch-feeders: the bill tip is packed with pressure-sensitive sense organs that detect prey deep in wet mud without the bird seeing it, and in many species only the outermost part of the upper mandible can be raised, so that a worm is gripped underground while the rest of the bill stays shut. Because bill and leg length differ widely between species, dozens of birds feed side by side on the same flat without crowding one another: one picks from the surface, another probes up to its eyes in the mud. A few species swim in tight circles and take whatever the vortex they create brings up. The nest is a trodden-out cup holding four eggs with the points inward; the chicks walk and find their own food almost at once. Over the breeding grounds display takes place high in the air, with a persistent thin call or, in some species, with a humming sound produced by the tail feathers spread into the wind.
• Gulls, terns and auks | LariThese waders are not tied to the shoreline: they take their food from or below the water surface, rest afloat on the open sea and hang in the air for hours on long wings - some of them rowing underwater with those same wings. They breed in colonies on cliffs, islets and beaches, with a small clutch that is often no more than one or two eggs. The young stay at the nest and are fed by both parents, in some species long after they can fly; years then pass before they breed themselves, and in the meantime they wear a succession of immature plumages. Not everything in the group fits that picture: genetic evidence also places here a few small, secretive birds of grassland.
• Jaegers and skuas | Stercorariidae5 speciesMuch of the food is taken from other seabirds: one victim is singled out in flight and chased through sharp turns until it drops or disgorges its catch, which is then snatched in the air or picked off the water. The bill is hooked at the tip and carries a horny plate at the base; the toes bear sharp claws. On the breeding grounds the diet changes completely: eggs, chicks, small rodents, berries and insects are taken, and in some species breeding depends so closely on rodent numbers that in poor years hardly any eggs are laid at all. The nest is a bare scrape on open ground, usually with two eggs; anyone coming too close is attacked at head height in low, screaming diving passes. Several species occur in both a pale and a dark colour form side by side, and in adults the central tail feathers project beyond the tail as points or spoons. Outside the breeding season life is spent on the open sea, far from any coast.
• Auks, puffins and murres | Alcidae21 speciesUnderwater the birds row with their wings, not their feet; the wings are therefore short and narrow, which allows dives of tens of metres but forces a fast, whirring wingbeat in the air and a laboured run-up across the water at take-off. In a number of species the catch is not swallowed but carried crosswise in the bill, sometimes a dozen small fish at once with their heads all facing the same way. Breeding takes place in dense colonies on cliffs, in rock crevices or in self-dug burrows; those that nest on a bare ledge lay a single, strongly pear-shaped egg straight onto the stone, with no nest material at all. In several species the young leaves the colony before it can fly: it drops down to the sea in darkness and is reared on from there by the male. The voice is a low growling, bleating or rattling that merges in a colony into a continuous drone; brightly coloured bill plates and head plumes are shed after the breeding season.
• Skimmers, noddies, terns and gulls | Laridae48 speciesUnder current classification the family includes not just gulls and terns but also the skimmers, and the bill shows it at a glance: gulls carry a stout bill hooked at the tip, suited to a generalist diet from carrion to garbage, terns a slender, pointed bill for plunging into the water from flight to seize fish, and the skimmer a unique bill, laterally compressed at the base, whose lower mandible is distinctly longer than the upper — it flies low over the water trailing that lower blade through the surface like a net. Larger gulls take several years to acquire their final, plain grey-and-white adult plumage, wearing a series of mottled brown immature plumages in the meantime, a maturation that in most other bird families is complete within a year. Gulls also routinely steal food from other birds by chasing them in flight and forcing them to drop their catch, a technique largely absent in terns and skimmers. When a colony is disturbed, dozens or hundreds of adults take to the air at once, calling loudly and diving at the intruder, a joint defence that rarely lets a trespasser leave unscathed.