Rationale (Changed due to Genuine (recent))

The regional Southern Ground-Hornbill Bucorvus leadbeateri population meets the population-size criterion for regionally Endangered, based on an observed, estimated and projected population size reduction over a three generation period, in the past (A2) or where the time period includes both the past and the future (A4), and where the reduction or its causes may not have ceased, or may not be understood, or may not be reversible, based on (b) an index of abundance appropriate to the taxon, (c) decline in Area of Occupancy, Extent of Occurrence and/or quality of habitat, and (d) actual or potential levels of exploitation. In addition, the population size is estimated to number less than2 500 mature individuals and to be undergoing a continuous decline of at least 20% over the next two generations satisfying criterion C1.

Distribution

The species occurs in suitable habitat in Kenya, Tanzania, Democratic Republic of Congo, Malawi, Zambia, Zimbabwe, Angola, Mozambique, Namibia, Botswana, Swaziland, and South Africa (Kemp 1995, Jordan 2011). In Swaziland, it was encountered only in the north-east in Hlane Royal National Park, Mlawula Nature Reserve and Mbuluzi Game Reserve (Monadjem et al. 2003). The EoO in South Africa has declined by approximately 66% in 115 years, or less than 3 generations (Kemp and Webster 2008), with about half of the regional population found in large protected areas, primarily Kruger National Park and Adjacent Private Nature Reserves. Groups outside this stronghold are patchily distributed in areas unaffected by expansion of rural communities, afforestation, bush encroachment, livestock diseases and cultivation (Morrison et al. 2005, Jordan 2011).

Birds are resident and occupy territories of up to 100-250 km2/group, depending on habitat quality (Jordan 2011, Theron 2011). Females occasionally move between groups and are sometimes found singly or in small groups of 2-3 members (Kemp 1995). Throughout the species' range, it occurs in habitats broadly classified as grassland and savannah, but it is absent from arid semi-deserts and extensive forests (Kemp 1995, Jordan 2011). A comparison of the EoO and AoO estimates of SABAP1 and SABAP2 show that, while the EoO of the species has not changed significantly since 1993, the AoO has decreased by 53.91%. It is unevenly represented in the Important Bird Area network with a reporting rate of 58.20% in Kruger National Park and reporting rates of less than1% in all other IBAs.

Habitat View more ecological information

Population

The global population of Southern Ground-Hornbill has not been quantified, owing to insufficient monitoring (BirdLife International 2014). Kemp (2000) provided a regional population estimate of 1 500-2 000 mature individuals based on densities from studies within Kruger National Park and central KwaZulu-Natal of territories of 100 km2/group (Kemp and Kemp 1974, Knight 1990), a breeding structure of one alpha breeding pair per group (Kemp and Kemp 1980) and a mean group size of 3.6 birds (Vernon 1986, Kemp et al. 1989, Knight 1990). This estimate was revised to 410-700 groups (1 290-2 380 individuals) in the initial working document for a PHVA process during 2005, with 1 500 breeding individuals and a threshold for saturation of 3 000 individuals used in the final Vortex modelling exercise (Morrison et al. 2005, 2007). The confidence in this estimate was high. An alternative analysis (Kemp and Webster 2008), using similar data based on biome extent and SABAP1 reporting frequencies, estimating 1 398 individuals in 1992 and 3 124 historically, which corroborates the Vortex estimates.

Population trend

Subjective regional declines were reported for Zimbabwe, Malawi, Tanzania and Kenya, hence the increased global concern which resulted in the elevation of this species to globally Vulnerable (BirdLife International 2014). In South Africa, the species is known to have undergone a decline of greater than 50% over the past three generations, as inferred from analyses of historical and atlas data (Kemp and Webster 2008).

Threats

The primary threats to the Southern Ground-Hornbill are habitat alteration, and especially loss of large trees with suitable cavities for nesting, as well as afforestation of grassland, or bush encroachment of savannah (Kemp 2005). Other factors that contribute to declines in population numbers include poisoning, electrocution and persecution of groups for breaking windows of buildings or cars when hammering at reflections with their bills (Kemp and Webster 2008). The birds are apparently only rarely collected for use in traditional practices, but they still appear in markets (Bruyns et al. 2013, Whiting et al. 2013).

Conservation

Underway

A Southern Ground-Hornbill Action Group was formed in 2005 (Morrison et al. 2007) and involves all role-players focused on the conservation and monitoring of this iconic African species. This group revised a Population and Habitat Viability Assessment (PHVA) for the species, originally compiled in 2005, and a Species Recovery Plan in 2011. These documents form the basis of the work undertaken by the Southern Ground-Hornbill Action Group. Conservation activities include establishment of a viable captive-breeding population and introduction of redundant, second-hatched, hand-reared chicks to re-establish groups within areas of the historical range that are still considered suitable for this purpose. The Southern Ground-Hornbill is listed under Schedule 2: Specially Protected Wild Animal under the Limpopo Environmental Management Act No 7 of 2003.

Proposed

The Southern Ground-Hornbill Action Group is working on a number of conservation activities. A document outlining appropriate criteria for proposed sites for re-introduction is being compiled.

Research

* A study to fill gaps in knowledge regarding the habitat requirements of the Southern Ground-Hornbill over a cross-section of existing occupied habitats, including non-protected areas under different management systems, should be conducted.

* Verify the species' current range across southern Africa, and update population size estimates and trends.

* Research into the population dynamics of the species, with a focus on recruitment in unprotected populations, and their dispersal abilities and processes, is recommended.

* Undertake an appraisal of likely impacts of climate change in relation to specific habitat requirements.

* Assess the extent and nature of trade in this species.