Taxonomic Notes
Specimens from the Wolkberg, an isolated mountain, appear to represent this species, and morphological differences are likely to represent intraspecific variation (Deschodt and Davis 2019). The Wolkberg record is treated as belonging to Gyronotus glabrosus for the purposes of this assessment, but a molecular study is however needed to confirm this (C. Deschodt pers. comm. 2023).
Justification
This species is listed as Endangered on the basis that it has an extent of occurrence of 550 km2, occurs in four or five known locations defined by threats from land transformation, and is subject to an ongoing decline in the extent and quality of montane grassland due to conversion of this habitat into tree plantations. This listing is necessarily precautionary as the species' ecology and its ability to adapt to plantation habitats are essentially unknown, but it is expected to depend on the continued presence of natural montane grassland.
Geographic Range Information
This species is endemic to South Africa where it is restricted to a cluster of localities in the northeast of the country, primarily along the upper northeast edge of the eastern escarpment (Davis et al. 2020), and is regarded as being extinct at the type locality (Crous and Roets 2014). It is also known from a disjunct record from the Wolkberg (Deschodt and Davis 2019). It is likely that knowledge of the distribution is fairly complete, since Gyronotus species to the south (e.g. Mt. Sheba) belong to different species (A. Davis pers. comm. 2023). It has been recorded between 575 and 2,005 m asl (Davis et al. 2020).
Population Information
This species apparently occurs in low densities (Davis et al. 2020). The type series, collected in 1975, consists of only five specimens. Other than two (possibly undated) records from Woodbush, it was not recorded again until late 2013. The 2013 survey recorded six individuals, corresponding to three mating pairs (Crous and Roets 2014). Prior to this rediscovery, the species had been presumed to be extinct following the destruction of natural vegetation at the type locality (Crous and Roets 2014). Only five were found on the Wolkberg from a series of around 10 traps, presumably baited with pig dung (C. Deschodt pers. comm. 2023).
Habitat and Ecology Information
This species has been collected from grassland and alpine pasture (the latter on sandy loam) in grassland and (as a single record) bushveld bioregions (Davis et al. 2020). It has been recorded in low numbers at the forest edge bordering grassland, but in lower numbers than in grassland (Crous and Roets 2014). Natural food associations are unknown, but it has been attracted to mixed human/cattle dung bait (type series) (Davis et al. 2020) and to pig dung (C. Deschodt pers. comm. 2023). Mean annual rainfall across the five known localities is 732 to 943 mm, and mean annual temperature is 12.5–18.9 °C (Davis et al. 2020). It is flightless and has been recorded by day in December and February (Davis et al. 2020).
Threats Information
This species occurs in an area in which much of the natural habitat (as much as 69% in the Woodbush Granite Grassland vegetation unit) has been transformed, primarily through the conversion of grassland to tree plantations (Davis et al. 2020). The type locality, Nerina Nature Reserve, has been cleared for extensive eucalypt forestry, and targeted surveys in 2000 failed to record evidence of a surviving population (Crous and Roets 2014). As a flightless, and consequently low-vagility species, this beetle is expected to be highly sensitive to habitat fragmentation (Davis et al. 2020) and all members of the genus seem to be sensitive to habitat disturbance (Crous and Roets 2014).
Use and Trade Information
There is presumably no use of or trade in this species.
Conservation Actions Information
This species is known from Lekgalameetse Nature Reserve (Davis et al. 2020), which is small (A. Davis pers. comm. 2023). Surveys are needed to clarify the full extent of this species' distribution in montane grasslands and to clarify the impacts of habitat disturbance and transformation (Davis et al. 2020). While its ecology remains poorly-known, its conservation probably depends on the effective preservation of natural grassland (Davis et al. 2020), including those at the edge of threatened Afromontane forest in the Tzaneen region from which the species was rediscovered in 2013 (Crous and Roets 2014).