Rationale
(Changed due to Not applicable)
The global population of the localised and easily overlooked Botha's Lark Spizocorys fringillaris satisfies criterion B2 (an AoO of less than 500 km2 and a continuing decline, observed, inferred or projected in (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or sub-populations and (v) number of mature individuals. Furthermore, the global population is estimated to number less than 2 500 mature individuals and is undergoing an estimated decline of greater than 20% over two generations. Breeding success and long-term survival are threatened by unfavourable land-use practices. Consequently this dwindling endemic is assessed as regionally Endangered.
Distribution
Botha's Lark is endemic to eastern South Africa's upland grasslands, with a restricted distribution centred on south-eastern Mpumalanga (Amersfoort, Bethal, Hendrina, Ermelo, Wakkerstroom, Volksrust and Standerton districts) and the adjacent eastern Free State (west of Wesselbron, Heilbron, Warden, Verkykerskop and Harrismith districts) (Barnes 2000). The bulk of its population occurs in the Vaal River catchment. New atlas data suggest it may have disappeared from the northern end of its range in central Mpumalanga, as well as parts of north-eastern Free State. Nevertheless, recent sight records from the Memel-Vrede-Warden-Harrismith arc (Nuttall 1999), and near Kroonstad and Wesselbron (Earlé and Grobler 1987), show that there are previously overlooked populations in the eastern Free State (Maphisa et al. 2009). The highly specific breeding and foraging habitat requirements, together with extensive transformation of its natural habitat, partly account for the rarity and limited range of this species (Barnes 2000).
Population
Barnes (2000) estimated the global population to be in the region of 1 500-5 000 individuals. The species no longer occurs at the type locality of Vredefort (Dean 1997), and similar local extinctions are documented or suspected in major parts of its range. The species is localised and generally sparse, but can be locally common in suitable habitat, with densities of c. 1 bird/km2 recorded in Mpumalanga (Tarboton et al. 1987). A total global population of 1 000 to 20 000 birds was estimated by Allan et al. (1983), revised by Siegfried (1992) to 1 500-5 000 individuals. With evidence of range contractions and local extinction events, it is likely that the current population of Botha's Lark is smaller still, and is suspected to be less than 2 500 individuals. However, detailed quantitative information and population and distribution surveys are required to draw more concrete conclusions. Confidence in this population estimate is low.
Population trend
With evidence of range contraction, it is possible that the current population of Botha's Lark has suffered a concomitant population decline. Data relating to population trends are lacking although the global population is suspected to have declined by at least 30% over the past three generations. The factors driving this predicted decline i.e. habitat loss and degradation, have not ceased and are likely to continue into the future. Confidence in this population trend estimate is low due to a lack of data.
Threats
As is the case with most other threatened grassland species, habitat destruction and modification through agriculture is the principal threat faced by Botha's Lark. Increased fragmentation of this species' remaining habitat, coupled with its increasingly patchy occurrence with minimal contact between sub-populations, is of concern (Barnes 2000). As it prefers heavily grazed grassland, such as on properties stocked with sheep or other livestock, or game animals, shifting of land-use practices away from mixed stock farming presents a major threat. Unsuitable fire regimes may also be detrimental; Maphisa et al. (2009) suggested that late burning of grassland may shorten the potential breeding season and force a peak in breeding that coincides with high predator numbers. A proportion of the core distribution lies within the Vaal River Basin, an important water catchment area not susceptible to commercial afforestation. However, at the edge of its range, such as along the Mpumalanga Escarpment, the species may be locally displaced by afforestation practices (Allan et al. 1997). The severity of this threat is now thought to be lower than previously suspected. Other potential immediate threats are human population expansion, urbanisation and mining. Botha's Lark is considered as being at low risk to the effects of climate change (Simmons et al. 2004). Given its geographically limited, fragmented and decreasing distribution, the loss of even a small, localised sub-population could have a significant effect on the long-term survival of this endemic species.
Conservation
Underway
To date no conservation actions that focus specifically on Botha's Lark have been put in place. Being a small, cryptic and easily overlooked species, Botha's Lark has not received the conservation attention that its already precarious, and apparently worsening status, urgently warrants.
Proposed
A Population and Habitat Viability Assessment (PHVA), culminating in a National Species Recovery Plan, is recommended. The species is not represented in formally conserved areas and is currently absent from the protected area network (Siegfried 1992). The conservation of Moist Clay Highveld Grassland, which is critical for the conservation of Botha's Lark, has largely been left to private land-owners. This species is heavily reliant on intense grazing and frequent burning to maintain its specific preferred microhabitat, and these conditions are mostly found on privately owned stock or game farms. Research into its ecological requirements, and the establishment and implementation of beneficial land-management plans (concerning especially grazing pressure and timing and frequency of burning) are essential. Close cooperation between conservation agencies and land-owners is thus imperative. Education, incentives, monitoring and encouragement of sustainable avitourism are valuable conservation approaches. Continued distribution mapping and field surveys are important steps towards identifying priority conservation areas. Research into how increasing population fragmentation is influencing this species' genetic integrity, is also a high priority (Barnes 2000).
Research
* Field surveys, distribution mapping and population estimates by experienced observers are urgently required before major conservation actions can be planned or implemented.
* Research into the ecological requirements of the species, and its responses to different land-use strategies, should be conducted to assist conservation agencies to plan effective survival strategies for the species, and to advise land-owners on appropriate land-management strategies to benefit Botha's Lark.
