The Recurvirostridae are a family of

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s in the

wader 245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...

suborder Charadrii. It contains two distinct groups of birds, the

avocet The four species of avocets are a genus, ''Recurvirostra'', of waders in the same avian family as the stilts. The genus name comes from Latin , 'curved backwards' and , 'bill'. The common name is thought to derive from the Italian ( Ferrarese) ...

s (one genus) and the stilts (two genera).

Description

Avocets and stilts range in length from and in weight from ; males are usually slightly bigger than females. All possess long, thin legs, necks, and bills. The bills of avocets are curved upwards, and are swept from side to side when the bird is feeding in the brackish or saline wetlands they prefer. The bills of stilts, in contrast, are straight. The front toes are webbed, partially in most stilts, and fully in avocets and the

banded stilt The banded stilt (''Cladorhynchus leucocephalus'') is a nomadic wader of the stilt and avocet family, Recurvirostridae, native to Australia. It belongs to the monotypic genus ''Cladorhynchus''. It gets its name from the red-brown breast band fo ...

, which swim more. The majority of species' plumage has contrasting areas of black and white, with some species having patches of buff or brown on the head or chest. The sexes are similar. Their vocalizations are usually yelps of one or two syllables.

Distribution and habitat

Avocets and stilts are a cosmopolitan family, being distributed on all the world's continents except Antarctica, and occurring on several oceanic islands. Several species are wide-ranging and a few are locally distributed. One species, the

black stilt The black stilt (''Himantopus novaezelandiae'') or kakī (Māori) is a wading bird found in New Zealand. It is one of the world's rarest birds, with 169 adults surviving in the wild as of May 2020. Adult kakī have distinctive black plumage, l ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

, is critically endangered due to

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

, introduced predators, and hybridisation with the

pied stilt The pied stilt (''Himantopus leucocephalus''), also known as the white-headed stilt, is a shorebird in the family Recurvirostridae. It is widely distributed with a large total population size and apparently stable population trend, occurring in ...

Feeding

These species feed on small aquatic animals such as

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

brine shrimp ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia L ...

and other

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s, larval

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s, segmented worms,

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found ...

s, and small

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

Breeding

Stilts and avocets breed on open ground near water, often in loose

colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

. They defend nesting territories vigorously with aggressive displays, and mob intruders and possible predators with a great deal of noise. They are monogamous, although the pair bonds are not maintained from season to season. Their eggs are light-coloured with dark markings, weighing . Three to four are laid in simple

nests A nest is a structure built for certain animals to hold eggs or young. Although nests are most closely associated with birds, members of all classes of vertebrates and some invertebrates construct nests. They may be composed of organic materi ...

, and both parents share the incubation duties, which last 22 to 28 days. The banded stilt may breed only every few years, as it breeds on temporary lakes caused by rains in the deserts of Australia. The chicks are

downy Downy, also known as Lenor in Europe, Russia and Japan, is a brand of fabric softener produced by Procter & Gamble that was introduced in 1960. Lenor is a brand name of fabric softener and dryer sheets, also produced by P&G, sold in Europe, Rus ...

and

precocial In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...

, leaving the nest within a day of hatching; they fledge in 28 to 35 days. In all species except the banded stilt, the chicks are cared for by the parents for several months, and they may move them to new areas and defend territories there. Banded stilts deviate from this by collecting their chicks in massive crèches numbering several hundred.

Taxonomy

The taxonomy of the stilts is particularly debated, with the genus ''Himantopus'' considered to have two to six species.

References

*Pierce, R.J. (1996) "Family Recurvirostridae (Stilts and Avocets) P.p. 332-348 ''in'' del Hoyo, J.; Elliot, A. & Sargatal, J. (editors). (1996). '' Handbook of the Birds of the World. Volume 3'': Hoatzin to Auks. Lynx Edicions. {{Taxonbar, from=Q27042 Bird families Taxa named by Charles Lucien Bonaparte