Rationale
(Changed due to Not applicable)
Only a small remnant population of the attractive Yellow-throated Sandgrouse Pterocles gutturalis, probably numbering less than 1 000 mature individuals, persists within the region. In addition to having such a small remaining stronghold, the species qualifies as regionally Vulnerable under criterion C2, in that all the mature individuals occur in a single sub-population. Furthermore, the species does not occur in substantial numbers in any formally protected area, although the unprotected, privately-owned Northern Turf Thornveld IBA (SA009) supports an important population. The species is reliant on crop agriculture, which provides it with food in the form of pioneer plant seeds and fallen grain, nesting habitat in fallow fields, and abundant drinking points (for irrigation). In the Yellow-throated Sandgrouse's case, a tenuous balance exists between commercial farming and conservation: although it is not ideal that the species relies entirely on continued human activity for survival in the region, it would probably become regionally extinct should crop agriculture cease altogether.
Distribution
The Yellow-throated Sandgrouse has a highly fragmented Afrotropical distribution, occurring discontinuously from northern Ethiopia through East Africa, southwards to southern Africa (Urban et al. 1986). In southern Africa it occurs predominantly in Botswana and north-western South Africa with scattered records in western Zimbabwe and northern Namibia (Maclean 1997). It is exceptionally localised within the region, being restricted to the north-eastern part of North West Province and the adjacent south-western corner of Limpopo Province, occurring from around Brits to the Limpopo River, and northwards to Thabazimbi.
Its movements are not well understood: the species was previously viewed as an irruptive nomadic visitor in the region, but it appears that a stable, resident population has become established thanks to the Yellow-throated Sandgrouse's ability to forage and breed in a transformed agricultural matrix (Maclean 1997). Farmers report that the birds have been resident since at least 1960 (Blane and Tarboton 1990). While it appears that South African birds are mostly sedentary, birds from Zambia may supplement populations in Botswana during the summer wet season (Brooke 1968, Brewster 1991, Barnes 2000).
Its range within the region has contracted significantly since the 20th century (Maclean 1997), and the species is now absent from the vicinity of Kuruman, Potchefstroom, Zeerust and Middelburg, where specimens were collected in the 1800s (Stark and Sclater 1903, Brooke 1968). A comparison between SABAP1 and SABAP2 atlas projects suggests the AoO has declined from 10 331 km2 to 5 925 km2 representing a 42.65% decline.
Population
The global population size has not been quantified, but the species is described as generally uncommon and local (Madge et al. 2002). Blane and Tarboton (1990) and Tarboton et al. (1999) estimated the size of a resident population in an agricultural landscape in the Northam area at c. 300-500 birds in 95 km2, based on counts of drinking birds; extrapolation to other climatically, topographically and paedologically similar areas suggest that the regional population may be ‘thousands to tens of thousands' (Tarboton et al. 1999). However, given the intrinsically limited distribution and apparent decrease in AoO, the regional population may be less than1 000 mature individuals, although confidence in this estimate is low.
Population trend
The global population is suspected to be in decline owing to ongoing habitat destruction (BirdLife International 2014). A comparison of the distribution between SABAP 1 and SABAP2 suggests a possible decrease in the AoO in South Africa, which may indicate a similar decline in numbers although the rate of decline is has not been determined. Confidence in the regional population trend estimate is low.
Threats
While there are no immediate concerns regarding the conservation of this species in the region (Little 2014), the reliance of Yellow-throated Sandgrouse on current crop farming cycles, especially the availability of and quality of fallow fields, make the birds susceptible to a change in agriculture practices (Tarboton et al. 1999). The winter breeding season coincides with peak ploughing of fields in preparation for planting of spring crops, and a high proportion of nests are destroyed by such activities, e.g. six of 13 nests found in one year were destroyed in this fashion (Blane and Tarboton 1990). The potential effects of agricultural herbicides should also be researched (Little 2014). Hunting (wing-shooting) of Yellow-throated Sandgrouse is not permitted in the North West Province. Provided this law is enforced, the birds should not be at risk. As the birds are known to feed on fallen grains of commercial crops such as oats, wheat, barley, sorghum and soya-bean (Lloyd 2005), the species may be perceived as an agricultural pest, particularly where high densities occur locally. It may also be inadvertently shot during efforts to control the superficially similar Speckled Pigeon Columba guinea, an established agricultural pest. The potentially adverse effects of climate change, and resultant changes in e.g. farming practices, land-use and levels of bush encroachment, on the quality and quantity of suitable habitat should be investigated. A large number of mines are located within the range of this species, and it is a concern that the footprint of mines in the area is increasing; however, mining properties may indirectly safeguard remaining natural habitat, and provide additional drinking points.
Conservation
Underway
No species-specific conservation measures are currently underway. The Northern Turf Thornveld IBA (SA009) was proclaimed specifically to safeguard the last remnant of the Yellow-throated Sandgrouse population in the region (see Barnes 1998). This collection of private agricultural farms covers c. 56 000 ha in south-western Limpopo, in the triangle between the Crocodile River, Bierspruit River and the confluence of these rivers just south of Thabazimbi; the southern boundary is formed by the road between Bierspruit/Northam and Koedoeskop. A recent review suggests that the Yellow-throated Sandgrouse population is relatively healthy, with the birds having adapted to foraging in fallow fields over the past few years as much of their natural habitat has been transformed into agricultural land, especially through the establishment of centre-point irrigation schemes.
Proposed
The survival of this species in South Africa is dependent on crop farming, and is therefore linked to education and awareness of private land-owners. Tarboton et al. (1999) identified three key factors that would affect the survival of the Yellow-throated Sandgrouse in the region: availability of one-year fallow fields, timing of ploughing of lands, and availability of drinking sites; all of these can be manipulated in the existing agricultural framework, e.g. by ploughing mainly in the summer non-breeding season, or providing incentives to farmers to establish cycles that promote optimal breeding habitat. Tarboton et al. (1999) suggested that if such management strategies are implemented effectively, Yellow-throated Sandgrouse populations may even have potential to be hunted sustainably, providing a financial motivation for long-term conservation planning. Nevertheless, given the relatively small, fluctuating and isolated regional population, continued monitoring is warranted.
Research
* Continued population estimations, ideally through simultaneous counts at drinking sites at an annual, biannual or monthly basis, should be undertaken to monitor population health and breeding productivity.
* Threats impacting upon this species and its habitat should be re-evaluated.
* Investigate why the species is so restricted.
