Data Zone
Justification of Red List category
This species is listed as Endangered because it is considered to be declining rapidly over three generations owing to increased habitat loss and degradation.
Population justification
Siegfried (1992) suggested a global population of 1,500-5,000 individuals. Estimates for the proposed Grassland Biosphere Reserve suggest that 2,500 individuals is a more realistic lower limit for this species. This range is roughly equivalent to 1,700-3,300 mature individuals; however, the total may be significantly lower (D. Maphisa in litt. 2012, 2016).
Trend justification
Much of the population may be on private land and it is an elusive species, which makes it difficult to get accurate population measures (D. Maphisa in litt. 2016). Analyses of Southern African Bird Atlas Project data have shown a possible 40% decline in range (with a 14% decline in core range) (Lee et al. 2017), and Peacock (2015) estimate the decline at >50%. However, its absence has recently been noted at former strongholds, particularly at Mataliele (where it is now presumed extinct) (D. Maphisa in litt. 2007; N. Theron and R. Colyn in litt. 2016). Suspected declines in the Wakkestroom population have also been raised (N. Theron and R. Colyn in litt. 2016), with repeat surveys in 2016 of 33 transects originally covered in 2002 (Maphisa 2004) showing declines in both the number of transects (down from 9 to 5) where the species was found, and the number of individuals recorded (down from 32 to 9) (Gush 2017). The species is therefore inferred to be in severe decline, with the decline over ten years tentatively placed in the range of 50-79%.
Heteromirafra ruddi is an endemic resident of east South Africa. Although records are spread over a large area, its distribution within this area is patchy. The core of its restricted range has been centred on south-east Mpumalanga, north-west KwaZulu-Natal and the north-east Free State, however, up to date information is lacking for much of this range (D. Maphisa in litt. 2016). Small, isolated populations are found farther north in the Dullstroom-Machadodorp district, and possibly at Ncora Dam and Molteno in the Eastern Cape; although there have been no confirmed sightings for several years around Dullstroom and it may have become locally extinct in areas of Eastern Cape (Peacock 2015; R. Colyn verbally 2017). A population at Matatiele in west KwaZulu-Natal has possibly gone extinct (N. Theron and R. Colyn in litt. 2016). Further surveys in 2010 between the Normandien pass and Ncandu Nature Reserve had a possible alarming individual, but no sighting was confirmed (D. Maphisa in litt. 2016). The overall population was not thought to have decreased significantly since the mid-1990s (P. Ryan in litt. 2005), however its absence has been noted at former strongholds, suggesting it is now in decline (D. Maphisa in litt. 2007), and comparison of data in South African Bird Atlas Project 1 and 2 indicates a reduction in area of occupancy of over 50% (D. Maphisa in litt. 2012). Historical records from Warden in the Free State and sight records from the Memel-Vrede-Warden-Harrismith arc suggest that there may be a substantial, previously overlooked, population in the eastern Free State, and the remaining natural grassland in the area looks suitable, although agriculture is intense (D. Maphisa in litt. 2016). The global population has been estimated at 1,500-5,000 individuals (Siegfried 1992). A lower limit of 2,500 individuals has been suggested as more realistic (Barnes and Tarboton 1998), but it has been suggested that the lack of new sites and disappearance from former strongholds mean the total population may be much lower (D. Maphisa in litt. 2012, 2016).
It is found within open, grazed, level grassland mostly with minimal forb invasion, in high rainfall (>600 mm p.a.), sour grassland regions. It favours stone-free areas of natural grassland on flat or gently-sloping hilltop plateaux, with short (4-9 cm) to medium (6-8 cm) grass cover, avoiding areas with tall, dense or insufficient grass cover (Maphisa 2004). Relatively high abundances are found at severely grazed sites, although few birds breed in such habitat, where breeding success is low (D. Maphisa in litt. 2007). The Molteno site is never burned, and suitable habitat is maintained by stocking cattle in the winter and removing cattle after the first rains, while indigenous grazers such as Black Wildebeest and Blesbok are present at the site throughout the year but at low densities (N. Theron and R. Colyn in litt. 2016). By not burning, dry grass is available at the start of the breeding season, and may allow pairs to breed earlier than at other sites within the species range (N. Theron and R. Colyn in litt. 2016). This species also favours edges of pans and vleis. Recent research indicates that the species would best be conserved under controlled mixed stocking rates of sheep and cattle with burning carried out every second year (Maphisa 2004). The species requires habitat heterogeneity for nest concealment and foraging during the breeding season. The most suitable breeding habitat appears to be moderately to lightly grazed unburned or burned sites. The nest is a cup covered with a dome, constructed from old grass and lined with fresh dry grass. Egg laying occurs from October to April, with peaks in January and February (Maphisa et al. 2009). The clutch size is two to four, but most commonly three, eggs (Maphisa et al. 2009). The incubation period is 13-14 days and the fledging period is c.13 days (Maphisa et al. 2009). Nestlings are fed on young locusts, other insects, worms and arachnids (Maphisa 2004).
Habitat loss and fragmentation, as a result of agricultural intensification, inappropriate pasture management and afforestation, have resulted in local population reductions. Grasslands are modified into fields for cultivation and grazing or claimed for housing (Maphisa 2004), and this may have played a role in the possible extinction of the species in the Matatiele region (N. Theron and R. Colyn in litt. 2016) which had previously held to highest density of Rudd's Lark in South Africa (Hockey et al. 1988). Further commercial afforestation may take place below the escarpment, and poses little threat to the species (D. Maphisa in litt. 2007). Human settlement and other developments are considered a major threat to the species's habitat (D. Maphisa in litt. 2007; N. Theron and R. Colyn in litt. 2016). Uncontrolled ploughing of pristine/near-pristine habitat as part of agricultural initiatives to alleviate food shortages has also been reported (A. Burns in litt. 2005), especially prevalent in the Matatiele area (N. Theron and R. Colyn in litt. 2016). The other primary threats are unsuitable fire regimes and grazing practices. It is also threatened by mining, although plans for the exploration of three sites in the Wakkerstroom area for torbanite and coal by Delta Mining Consolidated (Verdoorn 2008) have apparently since been scrapped. Late burning of grassland might shorten the potential breeding season and force a peak in breeding that coincides with high predator numbers (Maphisa et al. 2009). Extensive wildfires in Mpumalanga and Free State in 2007 may have caused a decline in the species's population (N. Smith in litt. 2007). Within South Africa as a whole, 60-80% of grassland has been irreversibly transformed. All of South Africa's maize crop and much of its wheat is produced in former grassland areas, illustrating the magnitude of threats this species faces today. The new emerging threats include construction of dams to generate electricity or wind farms (Maphisa 2015). Climate change is also predicted to have future impact on this species (Huntley and Bernard 2012). The loss of the species's habitat over the next 10 years could be moderate (<50%) unless planned intervention takes place. Predation has been observed as the main cause of nest loss, with mongooses, rodents and snakes identified as the main predators (Maphisa et al. 2009).
Conservation Actions Underway
Verloren Valei Nature Reserve, which was recognised as a Ramsar site (Ramsar Directory: http://www.wetlands.org/RDB/Ramsar_Dir/SouthAfrica/ZA017D02.htm), may now no longer support the species (D. Maphisa in litt. 2012). The Matatiele Commonage was declared a nature reserve in 2007 in part to conserve the species. However, the fencing of the area and removal of cattle lead to a change in habitat structure rendering the site unsuitable for Rudd’s Lark (Theron and Colyn in prep). The developing land stewardship programme centred around Volksrust and Wakkerstroom is estimated to hold c.85% of the global population (Barnes 1998; A. Burns in litt. 2005). Current Land Stewardship initiatives in the Memel region also have the potential to contribute to the conservation of the species (N. Theron and R. Colyn in litt. 2016). It is listed as Endangered in the 2015 Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland (Peacock 2015).
14 cm. Small, large-headed and short-tailed lark with large dark eyes. Buff stripe in centre of crown diagnostic when crest erect. Long, flesh-coloured legs. When threatened it has a habit of running fast on the ground before suddenly stopping. Otherwise rather tame and confiding and may easily be overlooked. In flight shows short, very thin tail and large rounded wings. Similar spp. Spike-heeled Lark Chersomanes albofasciata has white tip to its short tail.
Text account compilers
Clark, J.
Contributors
Allan, D., Burns, A., Colyn, R., Donald, P., Ekstrom, J., Harding, M., Lee, A., Maphisa, D., Pilgrim, J., Ryan, P.G., Shutes, S., Smith, N., Stattersfield, A., Symes, A., Tarboton, W., Taylor, J., Theron, N. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Rudd's Lark Heteromirafra ruddi. Downloaded from
https://datazone.birdlife.org/species/factsheet/rudds-lark-heteromirafra-ruddi on 22/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/11/2024.