Rationale
(Changed due to Genuine (recent))
Rudd's Lark Heteromirafra ruddi was assessed as Critically Endangered in the 2000 assessment; however, the threats faced by this unique highland endemic are less severe than previously feared. Nevertheless, it still satisfies the population size criterion for regionally Endangered (reduction of greater than 50% in the past three generations). The species has a small range, is known from few localities and is suspected to be experiencing a continuing decline in the extent and quality of habitat, and number of mature individuals.
Distribution
Rudd's Lark is a highly localised resident species, endemic to the high-altitude grasslands of eastern South Africa (Hockey et al. 1988). It has precise habitat requirements and therefore a naturally restricted range and small population; this situation is exacerbated by habitat modification by humans (Hockey et al. 1988). The core of its range is centred on south-eastern Mpumalanga (Wakkerstroom, Amersfoort, Belfast, Waterval Boven, Ermelo, Volksrust districts), eastern Free State (Warden, Verkykerskop, Memel) and north-western KwaZulu-Natal (Barnes 2000g). The species reaches its northern limits in the Steenkampsberg range near Dullstroom in Mpumalanga where a small, isolated population exists (Dean and Allan 1997).
Being notoriously inconspicuous unless singing, this species is easily overlooked, and increased observer awareness has led to its recent discovery, or rediscovery, in several areas. Brooke (1984) feared the species to be extinct in southern KwaZulu-Natal, but surveys in the 1980s confirmed that a small population persisted at Matatiele, about 300 km south of the main area of distribution (Hockey et al. 1988). In the 1990s, additional localities were discovered 200 km further south near Ncora Dam, in southern Transkei, as well as near Molteno in the eastern Eastern Cape (Dean and Allan 1997). Three specimens collected from the farm Nooitgedacht near Warden (Herholdt and Grobler 1987), and multiple sight records from the Memel-Vrede-Warden-Verkykerskop-Harrismith arc east of 29° E, revealed the existence of a substantial previously overlooked population in the eastern Free State/western KwaZulu-Natal border region (Hockey et al. 1988). The species was also reported from the Bedford/Chatsworth IBA (Maphisa 2004).
Distribution modelling suggests that Rudd's Lark may have a larger distribution than current records suggest (Maphisa et al. 2009). However, during SABAP2 data gathering, the species was reported only from the Memel-Verkykerskop area in Free State, and the Wakkerstroom-Amersfoort area of Mpumalanga, and a comparison between SABAP1 and SABAP2 data suggests a reduction in AoO of c. 55%. In addition, preliminary field surveys have prompted concerns about disappearances from former strongholds (Maphisa et al. 2009). However, it is likely that this cryptic and localised species still occurs, but was overlooked, in some areas where it was not recorded during SABAP2. Nevertheless, it is undeniably one of the most range-restricted birds in the region.
Population
The species is generally scarce and patchily distributed even within the core of its range (Dean and Ryan 2005). In optimal habitats it can occur at relatively high densities e.g. 15 singing males in approximately 4 km2 were documented at Matatiele (Hockey et al. 1988). In the Wakkerstroom district in Mpumalanga, one of the main strongholds (Hockey et al. 1988), it can also be locally common, e.g. five nests were located in 8 ha hectares of grassland fringing a small pan, where 11 displaying males were estimated to be present (Tarboton et al. 1987). Crude estimates suggest that Rudd's Lark has a global population of 1 500-5 000 individuals (Siegfried 1992), but estimates for the proposed Grassland Biosphere Reserve suggest that 2 500 individuals is a more realistic lower limit for the species (Barnes 2000). This range is roughly equivalent to 1 700-3 300 mature individuals (BirdLife International 2014). Taking into consideration the apparent absence from much of its former range according to SABAP2 records, together with predicted population declines (Allan et al. 1997), a precautionary approach warrants that the global population should be considered to fall below the threshold of 2 500 mature individuals, thus classifying this species as regionally (and by default) globally Endangered. In the absence of more complete population and distribution data, confidence in this estimate is low.
Population trend
Barnes (2000) suggested that the population may decline by up to 80% over the next 15-20 years or three generations, thus classifying this species as Critically Endangered. However, its status was downgraded to Vulnerable in 2006, because the threats facing this species were not as severe as initially thought (BirdLife International 2014). Nevertheless, the population is probably decreasing (Maphisa et al. 2009), although the extent and tempo of this decrease are unclear. The total population may be significantly smaller as disappearances from former strongholds have been noted (BirdLife International 2014), and probable decreases in EoO and AoO were revealed by SABAP2 data. An estimate of a greater than 50% decline over the past three generations is provided. Confidence in this population trend estimate is low.
Threats
Rudd's Lark is a highly specialised and naturally localised inhabitant of grassland, the most threatened but least protected habitat in southern Africa (Dean and Allan 1997). Furthermore, it is estimated that less than1% of the maximum global population (c. 100 birds) occurs in formally protected areas (Siegfried 1992). As with most threatened grassland species, loss, degradation and fragmentation of its habitat are the main threats faced by Rudd's Lark, and has resulted in local population reductions (Barnes 2000). Changes in its sensitive grassland habitat are mostly brought about by commercial afforestation, agricultural intensification or unfavourable pasture management. The first-mentioned is believed to constitute a major threat, particularly in the Wakkerstroom area (Barnes 2000), although afforestation below the escarpment is believed to pose little threat to the species (Allan et al. 1997). Direct habitat destruction for the purposes of mining, housing and human settlements and agricultural initiatives to alleviate food shortages, all have a negative impact on this species (Barnes 2000).
A close relationship between grassland management, especially in terms of grazing pressure and fire regimes, the length of the breeding season, and nest success has been postulated (Maphisa et al. 2009). Unfavourable burning practices may also be detrimental to Rudd's Larks; for example, nesting success is higher in territories that were burned earlier in the breeding season, compared to territories that were burned later in the season, resulting in a shortened breeding windows and increased predation rates (Maphisa et al. 2009). Extensive wildfires may lead to local population declines and nest destruction. Rudd's Lark is believed to be at low risk from climate change (Simmons et al. 2004).
Conservation
Underway
Understanding how this species responds to different land-use practices is central to conservation planning and it is critical to identify management practices suitable to maintaining its preferred habitat. Research has been conducted on the fine-scale habitat requirements of this species (Maphisa 2004, Maphisa et al. 2009). Site-based and regional conservation actions, such as developing land stewardship programmes and taking steps towards securing the future of the proposed Grassland Biosphere Reserve (which would encompass c. 8% of the global population) are being undertaken by BirdLife South Africa. At present, the only formally protected area supporting this species is Verloren Valei Nature Reserve near Dullstroom, Mpumalanga, where small numbers have been recorded (Barnes 2000). Concerns have been expressed that this site, which was designated as a Ramsar site in 2001 (Ramsar number 1110) may no longer support the species, and field surveys are urgently required.
Proposed
The long-term survival of Rudd's Lark is largely reliant on beneficial management of grasslands by private land-owners. In particular, this would entail maintaining suitable grazing levels, as under- and overgrazed sites appear to support fewer larks. Fire is used extensively as a tool to control ticks and disease, improve forage for livestock, remove accumulated litter and promote grass regeneration. However, Maphisa et al. (2009) identified an important relationship between timing of breeding, the length of the breeding season and nesting success. Ideally, grasslands should be burnt in September or earlier, before the onset of the main breeding season. Likewise, Hockey et al. (1988) suggested that the species would be favoured by annual burning and heavy winter grazing, but in practice this regime is impractical. Further research into the ecological requirements of Rudd's Lark, and the effects different management practices have on the species, should be undertaken. Identification and implementation of appropriate land-use practices should be encouraged through education and awareness campaigns, and possibly through financial incentives (Tarboton et al. 1987) or through the encouragement of sustainable ecotourism. At some of the key sites for this species, conservation of intact avian communities is desirable, as Rudd's Lark often overlaps with other threatened or Near Threatened bird species such as Botha's Lark Spizocorys fringillaris, Southern Bald Ibis Geronticus calvus and Yellow-breasted Pipit Anthus chloris.
Research
* Field surveys are required to ascertain whether this species is still present at some of the sites where it was known to occur previously, but where it was not recorded during SABAP2, such as Matatiele in KwaZulu-Natal, the Molteno area of Eastern Cape and the Steenkampsberg in Mpumalanga. Surveys should be conducted by experienced observers, preferably at the onset of breeding when Rudd's Larks are most vocal and conspicuous.
* Where local disappearances or decreases in abundance have occurred, the causes of this should be investigated.
* Further research into the ecological requirements of the species, and land-uses suitable for fulfilling these requirements, should be undertaken.
