Ninety-eight shorebirds that nest in a scrape of earth
Scolopacidae packs sandpipers with woodcocks, curlews, and kin—long-bodied, long-legged waders with narrow, variable bills. Most nest in open scrapes, defending territories with aerial shows. Rafinesque named the family in 1815; about ninety-eight living or recently extinct species belong.
The family runs from the least sandpiper, as light as 18 grams and 11 centimetres long, to the Far Eastern curlew at up to 66 centimetres and the Eurasian curlew at up to 1.3 kilograms. Which sex is bigger varies: male ruffs outsize females, while female knots, curlews, phalaropes and godwits outsize males, and snipes and woodcock are about even. Compared with plovers, sandpipers have smaller eyes, slimmer heads and longer, thinner bills, and most have three forward toes plus a small hind toe, which the sanderling lacks. Plumage is mostly cryptic brown, grey or streaked, brightening in some species for breeding.
Bills vary enormously, from three times head length in the long-billed curlew to less than half in the Tuamotu sandpiper, and may be straight, slightly upturned or sharply downcurved. Dense touch receptors in a slight swelling at the tip let them feel prey in mud, since they rely on touch more than the sight-hunting plovers. They can also flex the upper bill without opening the whole jaw, which may make probing and handling prey easier. Feeding takes four broad forms: pecking with some probing on firmer ground, deep probing in soft mud and sand, the shanks' dashes through shallows after fish, and phalaropes pecking tiny prey from the water surface. Oddly, bill length does not seem to let coastal species divide up food; on sandy beaches many simply target mole crabs.
Sandpipers live everywhere except Antarctica and the harshest deserts, and most breed at moderate to high northern latitudes, including the world's most northerly nesting birds. Only a handful breed in the tropics, mostly snipes and woodcocks, plus the Tuamotu sandpiper of French Polynesia. Mating systems include monogamy, single-parent care by either sex, sequential polyandry and leks. Three or four eggs go into a sparsely lined scrape, parents trade incubation shifts of up to a day, and chicks hatch after about three weeks, walking and feeding within hours. Rafinesque named the family in 1815, and fossils include Paractitis from Oligocene Saskatchewan.
Source: Sandpiper
