The Rostratulidae, commonly known as the painted-snipes, are a family of wader that consists of two genera: Rostratula and Nycticryphes.
Description
The painted-snipes are short-legged, long-billed
similar in shape to the true snipes, but their
plumage is much more striking. There is sexual dimorphism in both size and plumage, with the males being duller overall and smaller. All three species have large forward pointing eyes.
Phylogenetics
The family Rostratulidae encompasses two genera and four species, one of which is extinct. Painted-snipes superficially resemble true
, but the two taxa are not closely related. Instead the similarity can be attributed to convergent evolution where both groups have been subjected to similar selective pressures, thus promoting the evolution of analogous features such as a long slender bill and legs, mottled
crypsis plumage and characteristic body proportions. While less similar in general morphology, the species that are most closely related to painted-snipes are other members of the suborder
Thinocori: jacanas,
, and the
plains wanderer.
[del Hoyo, J.; Elliot, A. & Sargatal, J. (editors). (1996). Handbook of the Birds of the World. Volume 3: Hoatzin to Auks. Lynx Edicions. ]
The species † Rostratula minator was described in 1988 from deposits of the early Pliocene found in Langebaanweg, South Africa. This is the first fossil attributed to the family Rostratulidae. Comparisons of bone measurements with R. minator and the Extant taxon species show that it was intermediate in size, although considerable differences indicate that it may only be an endemic African species that has become extinct, rather than a direct ancestor of R. benghalensis.[
]
The Australian painted-snipe was described as Rostratula australis by John Gould in 1838, although later lumped with the similar greater painted-snipe, R. benghalensis as subspecies R. b. australis. However, morphological and genetic differences have resulted in the species being restored in recent years.[ Baker AJ, Perreira SL, Rogers DI, Elbourne R and Hassell CJ (2007) Mitochondrial-DNA shows that the Australian Painted Snipe is a full species, Rostratula australis. Emu 107: 185-189] Such a similarity between the two species can be explained by a recent evolutionary divergence, and is an example of allopatric speciation where the prevention of gene flow by geographical isolation has resulted in an accumulation of differences by genetic drift and differing selective pressures.
Taxonomy
Family Rostratulidae: painted-snipes
Behaviour
All three species of painted-snipe generally inhabit reedy and marshes, usually in lowlands. Outside of the breeding season painted-snipes are generally solitary in habits. Painted snipes are crepuscular or even slightly nocturnal animal in their habits.
Feeding
Painted-snipes are omnivorous, feeding on and seeds. Animal prey taken includes annelid worms, snails, aquatic and marsh , and crustaceans. The seeds of grasses such as millet and rice are also consumed, and may form a major part of the diet of some populations.
Breeding
The breeding biology of the painted-snipes varies according to genus; the Rostratula painted-snipes are generally polyandrous whereas the South American painted-snipe is monogamous. The females of the genus Rostratula will bond with several males during a breeding season, but once the eggs are laid the males provide all the avian incubation and parental care. The bird nest of both species is a shallow cup, often built on a platform of vegetation. Clutch sizes range from 2–4 eggs, which are incubated for 15–21 days.
Conservation
At present, two species, the South American and greater painted-snipes, are not considered threatened by human activities; however, the Australian painted-snipe has declined and is considered endangered in Australia.[Lane, B.A.; & Rogers, D.I. (2000). "The Australian Painted-snipe, Rostratula (benghalensis) australis: an Endangered species?". Stilt 36: 26–34]
External links