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The elusive, forest-dwelling Spotted Ground Thrush Zoothera guttata has an estimated AoO of 260 km2 and is believed to be experiencing a continuing decline in (i) extent of occurrence, (ii) area of occupancy, (iii) area, extent and/or quality of habitat; and (v) number of mature individuals. The species is consequently assessed as regionally Endangered.
The Spotted Ground-Thrush has a widespread but fragmented distribution in Africa, occurring in the Democratic Republic of the Congo, Kenya, Malawi, Mozambique, South Africa, South Sudan and Tanzania (Ndang'ang'a et al. 2005). Within the region, breeding populations occur in mature coastal forests in Eastern Cape (including Mkambati Nature Reserve, Cwebe Nature Reserve, Dwesa Forest, Egossa Forest, Ntsubane Forest, Mtambalala Forest, Mpame Forest and Manubi Forest), and in Coastal Scarp and Valley forests in southern KwaZulu-Natal (Oribi Gorge) and northern KwaZulu-Natal (Ngoye Forest, Entumeni Forest and Dhlinza Forest (Berruti 1997, Harebottle and Barnes 2000). The South African population does not extend into southern Mozambique, and is essentially isolated from populations further north in Africa. The current southernmost limit of the regional population is around the Kei River in Eastern Cape; beyond this, forests are generally considered unsuitable to support significant populations of this species (Harebottle and Barnes 2000). Nevertheless, the Southern Ground Thrush was historically recorded as far south as Alexandria and Patensie near Port Elizabeth (Benson 1950).
Non-breeding birds undertake localised movements in winter, moving to scattered fragments of forests all along the coast from Lake St Lucia to Cove Rock (Harebottle 1994, Harebottle and Barnes 2000). A comparison of SABAP1 and SABAP2 data suggests that the species has undergone a reduction in range (in terms of EoO and AoO) since SABAP1. Ngoye Forest (70-100 pairs), Dhlinza Forest (20-25 pairs) and Entumeni Nature Reserve (20-30 pairs) are the most important sites for the conservation of the species and are listed as IBAs.
The global population has been estimated at 600-1 700 mature individuals (BirdLife International 2014). Harebottle and Barnes (2000) estimated that 800-1 600 mature individuals occur within the region, although forest degradation and alteration has undoubtedly led to reduced habitat availability and a consequent decline in population size. The regional population is estimated to be less than 600 mature individuals. Confidence in this estimate is low.
The global population is suspected to be declining due to habitat loss and degradation occurring throughout its range (BirdLife International 2014). Surveys of Kenyan coastal forest in 2003 suggest that the species may have undergone very rapid declines since the 1980s (Ndang'ang'a et al. 2005). The regional population is believed to be decreasing due to destruction and fragmentation of habitat in KwaZulu-Natal. Confidence in this estimate is low.
Although breeding sites are mostly conserved, continued deforestation of fragments of Coastal Dune, Scarp and Coastal Lowland forests in KwaZulu-Natal (wintering grounds) is a threat. In KwaZulu-Natal, 22 provincial nature and forest reserves have suitable habitat, but funding through Ezemvelo KwaZulu-Natal Wildlife for the protection of these sites is being reduced, threatening the viability of the sites. Planned coastal dune mining, south of Richards Bay, may have a negative impact on annual altitudinal migration of the northern KwaZulu-Natal population. Some casualties occur from collisions with buildings during migration. Predation, particularly of nests, by domestic cats Felis catus and Vervet Monkeys Chlorocebus pygerythrus is a factor of growing concern (Chittenden 2005). Climate change and range-change predictions suggest further range decreases, and concomitant population declines (BirdLife International and Durham University 2012).
There are no current active conservation actions in place for this species within the region. In 2005, under the auspices of the African Species Working Group, an International Spotted Ground Thrush Interest Group was formed, coordinated by an International Species Action Plan Coordinator and, at national level, by National Species Action Plan Coordinators. Unfortunately, very little implementation of its recommendations appears to have occurred to date. Globally, the species is listed in Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals. Regionally, the species is protected under the Environmental Conservation Act (Act No. 73 of 1989), as well as the KwaZulu-Natal Conservation Management Amendment Act (Act No. 5 of 1999).
A Population and Habitat Viability Assessment (PHVA) is recommended, as is a Biodiversity Management Plan, culminating in a National Species Recovery Plan. Ongoing monitoring of Spotted Ground Thrush populations at breeding sites needs to be undertaken. Improved conservation status of breeding, non-breeding and stop-over sites must be secured throughout its range. Legislative issues may need to be reviewed in Eastern Cape and KwaZulu-Natal. Awareness and publicity for conservation of the Spotted Ground Thrush among stakeholders should be raised.
* Studies of all breeding sites, and especially seldom-visited, isolated forest patches in Eastern Cape, need to be undertaken to determine the regional population size, status and productivity.
* Impacts of ecological factors on population dynamics at breeding and non-breeding sites need to be determined.