| Francolin | |
|---|---|
.jpg) | |
| Grey francolin | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Galliformes |
| Family: | Phasianidae |
| Subfamily: | Phasianinae |
| Tribe: | Gallini |
| Genera | |
Francolins arebirds in thetribeGallini that traditionally have been placed in thegenusFrancolinus, but now commonly are divided into multiple genera.[1]
As previously defined, they wereparaphyletic as the genusPternistis, which was previously included inFrancolinus, is more closely related toOld World quails than it is to the other francolins. Beginning in 2004, various ornithologists have recommended that it would be clearer to use "spurfowl" for all members of the genusPternistis and restrict the use of "francolin" to the other species presently or formerly classified inFrancolinus.[2] WhenPternistis is excluded, the francolins form amonophyletic clade that is asister group to a clade comprising thejunglefowl (Gallus) and thebamboo partridges (Bambusicola); together, these clades compose the tribeGallini.[1]
Although formerly classified in thepartridge subfamilyPerdicinae, this classification is no longer supported, and they are now classified in the subfamilyPavoninae.[1]
Francolins areterrestrial (though not flightless) birds that feed on insects, vegetable matter andseeds. Most of the members have a hooked upper beak, well-suited for digging at the bases of grass tussocks and rootballs. They have wide tails with fourteenrectrix feathers. Most species exhibitspurs on thetarsi.[3]
Of the approximately 17extant species, the natural range of five (composing the genusFrancolinus andOrtygornis) are restricted toAsia, while the remaining genera are restricted toAfrica.[4] Several species have been introduced to other parts of the world, notablyHawaii.
Twelve of the species which occur inAfrica are found in the subcontinental region of southern Africa; of these, seven occur in varying proportions within the political boundaries ofNamibia andZambia. Six southern African francolins are considered endemic to the subcontinent, of which three are found in Namibia and Zambia (theHartlaub's,red-billed andOrange River francolins).
TheCape spurfowl, endemic to theCape Province ofSouth Africa, occurs marginally in southern Namibia and southwestern Zambia. Afossil francolin,Francolinus capeki, has been described fromLate Pliocene deposits ofHungary; the contemporary fossil galliforms"Francolinus" minor and"F." subfrancolinus are now placed inPalaeocryptonyx.
Until the early 1990s, major authorities placed all francolins in thegenusFrancolinus.[4] In 1992 it was suggested that this treatment was problematic, and the francolins should be split into four genera:Francolinus for the Asian species, and the African species divided intoPeliperdix,Scleroptila andPternistis.[5] Thecrested francolin andNahan's francolin were considered possibly quite distinct, but still maintained inPeliperdix andPternistis respectively.[5] Based on further evidence, the crested francolin was moved to themonotypic genusDendroperdix in 1998,[6] and the Nahan's francolin was moved toPtilopachus in 2006.[7] Though some still maintain all these inFrancolinus,[8][9] the split into multiple genera is becoming more widespread.[10][11] In 2021, two species inFrancolinus (thegrey andswamp francolins) along with the crested francolin were moved into the genusOrtygornis, while three species fromPeliperdix (thecoqui,white-throated, andSchlegel's francolins) were moved into the new genusCampocolinus.Pternistis was moved to the tribeCoturnicini and, as with Nahan's "francolin", is no longer considered a francolin.[12][13][14][15]
When split, the English name "francolin" is generally restricted to the members of the generaFrancolinus,Ortygornis,Campocolinus,Peliperdix andScleroptila,[10][11] while the name "spurfowl" is used forPternistis ("spurfowl" is also used forGalloperdix of theIndian subcontinent).[10][11] As the Nahan's "francolin" is related to thestone partridge rather than the true francolins and spurfowl,[7][16] its name is sometimes modified to Nahan's partridge.[11]
In addition to the major changes proposed at genus level, the species leveltaxonomy among several francolins/spurfowl is disputed. For example, the distribution of theOrange River francolin (Scleroptila levaillantoides) is highlydisjunct, leading some authorities to split the northerntaxa (fromKenya and northwards) into a separate species, the acacia/Archer's francolin (S. gutturalis, with subspecieslorti), while maintaining the southern taxa (fromAngola and southwards) in the Orange River francolin.[4] Most authorities treat theElgon francolin (S.psilolaema elgonensis) as a subspecies of themoorland francolin,[4][8][9][10] but others have suggested it is a species (S.elgonensis), a subspecies of theShelley's francolin,[4] or even ahybrid between the moorland andred-winged francolins.[17]
With a paraphyletic classification, the genusPternistis in the tribeCoturnicini is also considered a francolin; due to the resulting paraphyly, this classification is no longer supported and has been recommended against.[2]
A Molecular Phylogeny of the Pheasants and Partridges SuggestsThat These Lineages Are Not MonophyleticR. T. Kimball,* E. L. Braun,*,† P. W. Zwartjes,* T. M. Crowe,‡,§ and J. D. Ligon*
