You’ve surely heard of snipes… but what of painted-snipes?
Caption: painted-snipes are really striking birds, and only superficially snipe-like. This is a female Greater painted-snipe. Image: afsarnayakkan, CC BY-SA 4.0 (original here).
Painted-snipes (technically Rostratulidae, part of the gull-wader-auk group Charadriiformes) are a small group of long-billed wading birds with large eyes, broad, short wings and a boldly patterned plumage that involves white shoulder stripes and bellies, and streaks and patches around the eyes. Females are larger and more boldly marked, especially in the (often, but not always, polyandrous) Greater painted-snipe Rostratula benghalensis of Africa, southern Asia and Australasia*. Females of this species are unusual among charadriiforms in possessing a crop; the slightly swollen anterior end of the bill in this species is also unusual. A second extant species – the South American painted-snipe Nycticryphes semicollaris (regarded by some authors as another member of Rostratula) – occurs in southern South America and differs markedly in its strongly downcurved bill tip, darker plumage, in lacking strong sexual dimorphism, and in having a pointed (rather than rounded) tail. Painted-snipes are omnivores that eat small invertebrates as well as seeds.
* The Australasian population is argued by some workers to represent a distinct species: the Australian painted-snipe R. australis. It differs from other greater painted-snipes in bill and leg proportions, in colour, and also in the form of its wing markings.
Caption: a South American painted-snipe photographed in Argentina. Image: Hector Bottai, CC BY-SA 4.0 (original here).
Despite their snipe-like appearance, painted-snipes have long been grouped with jacanas on the basis of a similar sternum shape, the presence of 10 (rather than 11) primaries and similar-looking downy chicks. This position has been supported by the majority of recent studies (Ericson et al. 2003, Hackett et al. 2008, Mayr 2011, Prum et al. 2015).
Caption: painted-snipes (this is a Greater painted-snipe) look very different from jacanas (this is a Wattled jacana Jacana jacana), but numerous lines of evidence indicate that the two share an ancestor. These images are among the hundreds of birds I’ve drawn for my in-prep textbook. Images: Darren Naish.
The fact that painted-snipes have a sister-group relationship with jacanas requires that they must have been in existence since the Early Oligocene, given the presence of fossil jacanas at least that old. At present, however, their only fossil occurrence is in the Lower Miocene of the Czech Republic and the Lower Pliocene of Langebaanweg, South Africa. These involve, respectively, an extinct species (R. pulia) named for a tarsometatarsus (and initially identified as a rallid) and a second (R. minator) known from limb bones and coracoids (Olson & Eller 1989, Mlíkovský 1998). R. minator appears to have been nearly 20% smaller than R. benghalensis and thus perhaps represents “an endemic African lineage that has become extinct” (Olson & Eller 1989, p. 121). Langebaanweg has yielded numerous other fossil birds (including penguins, tubenosed seabirds, grebes, ibises, storks, kingfishers, mousebirds and passerines) and is in fact one of the richest bird-yielding sites outside of the Pleistocene.
Caption: at left, we see humeri (A-D, dorsal view above, ventral view below) and tarsometatarsi (E-G, ) of Nycticryphes (A, E) and Rostratula benghalensis (C-D, G), with the known elements of the extinct R. minator shown as B and F. The species was clearly more like Nycticryphes than R. benghalensis in size. I’m not aware of a life reconstruction of this species. At right, we see images of the R. benghalensis skull in left lateral, dorsal and ventral views. The proportionally large orbits are obvious: note in dorsal view how narrow the frontals are in between them. Images: montage on left from Olson & Eller (1989); skull images from here on SkullSite.
This text is an excerpt from my in-prep giant textbook on the vertebrate fossil record, the construction of which can be supported via my patreon. I will get it finished eventually, but completion is still very literally years away.
For previous TetZoo articles on charadriiform birds, see…
The godwit’s many bills, January 2007
To the Sahara in quest of dinosaurs (living and extinct), December 2008
Mysterious channels of Alca torda, January 2009
Kleptoparasitism at Westbury Manor, January 2009
Mobile phones, medals, a doll's legs, an entire army... is there anything a gull won't swallow?, December 2009
The incredible bill of the oystercatcher, July 2010
Your Awesome Neighbourhood Herring Gull (And Its Many Cousins), September 2015
Avocets in Flight and Phylogeny, October 2018
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Ericson, P. G. P., Envall, I., Irestadt, M. & Norman, J. A. 2003. Inter-familial relationships of the shorebirds (Aves: Charadriiformes) based on nuclear DNA sequence data. BMC Evolutionary Biology 3: 16.
Hackett, S. J., Kimball, R. T., Reddy, S., Bowie, R. C. K., Braun, E. L., Braun, M. J., Cjojnowski, J. L., Cox, W. A., Han, K.-L., Harshman, J., Huddleston, C. J., Marks, B., Miglia, K. J., Moore, W. S., Sheldon, F. H., Steadman, D. W., Witt, C. C. & Yuri, T. 2008. A phylogenomic study of birds reveals their evolutionary history. Science 320, 1763-1768.
Mayr, G. 2011. The phylogeny of charadriiform birds (shorebirds and allies) – reassessing the conflict between morphology and molecules. Zoological Journal of the Linnean Society 161, 916-934.
Mlíkovský, J. 1998. A new painted snipe (Aves: Rostratulidae) from the Early Miocene of the Czech Republic. Časopis Národního muzea. Řada příriodovědná 167, 99-101.
Olson, S. L., & Eller, K. G. 1989. A new species of painted snipe (Charadriiformes: Rostratulidae) from the Early Pliocene at Langebaanweg, Southwestern Cape Province, South Africa. Ostrich 60, 118-121.
Prum, R. O., Berv, J. S., Dornburg, A., Field, D. J., Townsend, J. P., Moriarty Lemmon, E. & Lemmon, A. R. 2015. A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing. Nature 526, 569-573.
