Justification of Red List Category
This elusive grassland specialist qualifies as Vulnerable on the grounds that its small range (where it is known from few locations) and single small population are likely to be declining as a result of habitat degradation.
The population is estimated to number 2,500-9,999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.
The species has not been recorded in anthropogenic habitats despite survey effort in human modified grasslands. Therefore, widespread grazing and burning, as well as hunting pressure, are suspected to be driving an on-going population decline.
Turnix everetti is endemic to the island of Sumba, Nusa Tenggara, Indonesia (BirdLife International 2001), where it is apparently patchily distributed, but locally frequent, as at Yumbu where up to 17 have been recorded. Locals report it to be common during the maize harvest and unidentified buttonquails are encountered throughout the island. The species may therefore prove to be more widespread and abundant than currently suspected.
It inhabits sparse, dry grassland and scrub, often in a mosaic, from sea-level to at least 220 m, and appears to be less common in cultivated areas. At Yumbu, it was found in sparse natural grassland with occasional bushes on a raised coral limestone plateau, with all definite and possible records coming from areas with a 0.5-0.7 m sward height, interspersed with patches of shorter grass. It associates (and may be in competition) with other Turnix and Coturnix species. It has been postulated that resource partitioning in these species is related to bill morphology, the heavier bill of T. everetti being an adaptation to its diet of larger seeds. Although probably sedentary, seasonal movements may occur in response to food availability.
Assessment of the threat posed by the burning and clearance of habitat is complicated by the fact that this activity may actually increase habitat availability for the species. Nevertheless, much survey time has been spent in human-made grasslands, and its apparent absence from these areas suggests that it is constrained by an unknown ecological factor. It is quite possible, therefore, that overgrazing and burning are deleterious, and that competition with other species is a problem. Recent evidence suggests that it is often trapped for food, at least seasonally, and this may constitute a major threat.
Conservation Actions Underway
Recent surveys have provided important new information and a conservation project on Sumba has been initiated. While this project has submitted a proposal to gazette a network of seven protected areas on the island, it is unclear to what extent this will benefit this species.
13-14 cm. Small, short-legged, buttonquail. Upperparts vermiculated black, tawny, grey and white. Wing-coverts more rufous. Rich rufous chest, black-and-white scaling on sides of neck. White throat and belly. Stout blue-grey bill and pinkish legs. Similar spp. Sympatric race of Red-backed Buttonquail T. maculosa sumbana has small yellow bill, yellow legs, more extensive rufous on underparts and black spots on chest sides. Voice Undocumented.
Text account compilers
Benstead, P., Bird, J., Taylor, J., Davidson, P., Tobias, J., Westrip, J.
BirdLife International (2019) Species factsheet: Turnix everetti. Downloaded from http://www.birdlife.org on 19/08/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/08/2019.