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The regional population of Crowned Eagle Stephanoaetus coronatus meets the criterion for regionally Vulnerable under D1 (population size estimated to number less than1 000 mature individuals). In addition, the regional population is projected to undergo a continuous decline that may exceeds 10% over the next three generations, as stipulated in criterion C1.
The species is widespread throughout sub-Saharan Africa where it occurs from the lowland forests of West Africa, across to Ethiopia, and southwards to South Africa (Ferguson-Lees and Christie 2001). In southern Africa, it is restricted to Zimbabwe, central Mozambique and eastern South Africa and Swaziland, where it is strongly associated with Lowveld and escarpment forests, including riparian forest along the Limpopo and Luvuvhu rivers. While there may have been local range contractions owing to habitat destruction for commercial Pinus and Eucalyptus plantations (Simmons 2005), afforestation of former grasslands in Limpopo and Mpumalanga have resulted in an extension of available habitat (Tarboton and Allan 1984). KwaZulu-Natal and Eastern Cape seem to be the regional strongholds of this species. Incidental records from SABAP2 show birds ranging as far west as the Overberg, Western Cape, and Bronkhorstspruit, Gauteng, indicating possible minor westward shifts in the distribution range. The species is sparsely distributed in Swaziland with only four breeding pairs known (Monadjem et al. 2003), although it may have been overlooked in the Bulungu and Siceni mountains. The Crowned Eagle is well represented in the region's Important Bird Areas.
The global population of the Crowned Eagle has not been quantified but is thought to number in the thousands (BirdLife International 2014). No complete census of the regional population has been completed. Boshoff et al. (1994) estimated that there were 100 mature individuals within the borders of the old Eastern Cape Province up to the Fish River, and Quickelberge (1989) mentioned that the species was common in forested localities along the coastal strip from Port St. Johns to Mbotyi, being seen or heard on most days. Inaccessibility has led to parts of Eastern Cape being under-atlased. No estimates exist for KwaZulu-Natal. Based upon the number of pentads occupied in the province, one could estimate the population to be in the region of 400 mature individuals, although in urban areas their density can increase, e.g. there may be c. 40 mature individuals in eThekwini (Durban) Municipality alone (DG Allan pers. comm.). Likewise, up to 80 mature individuals are thought to occur within a 70 km radius of Nelspruit in Mpumalanga (GR Batchelor pers. comm.).
Parker (1994) estimated the Swaziland population at 60 mature individuals, but Monadjem and Rasmussen (2008) reported only four nests for the country, but admitted that nests may have been overlooked in Malolotja National Park, Kobolondlo Mountain, as well as the Lubombo Hills, where pairs have been sighted. Nevertheless, it appears that the Swaziland population has undergone a significant decline. Simmons (2005) concurred with Tarboton and Allan's (1984) estimate of 200 mature individuals in the north-east of South Africa, which included the current Limpopo and Mpumalanga provinces. A conservative estimate of the regional population is set at c. 800-900 mature individuals. Confidence in this regional population estimate is medium.
Globally, this species is threatened by persecution through trapping, shooting and nest destruction, competition for prey from humans, and habitat loss through deforestation (Ferguson-Lees and Christie 2001). This suite of widespread threats implies that the species is in moderately rapid decline, especially considering its slow reproductive rate. However, this decline is not currently thought to be severe, owing to the species' tolerance of modified habitats. The AoO estimates provided by SABAP2 may indicate a slight decrease in the regional population. In addition to this, it seems that there has been a decrease in the size of the Swaziland population based on the difference between estimates by Parker (1994) and Monadjem and Rasmussen (2008). For these reasons, the population trend is assessed to be negative. The confidence in this regional population trend estimate is low.
Crowned Eagles have been known to predate on small stock animals, chickens, dogs and domestic cats (Daneel 1979) and, recently, piglets (GR Batchelor pers. comm.), bringing the species into conflict with humans and resulting in persecution by stock farmers (Brown 1982). The loss of forest habitat has had a relatively small negative impact on the species because it has been able to adapt relatively well to nesting in alien plantations.
The Crowned Eagle Working Group consists of members of the Lowveld Bird Club, which is a member of Birdlife South Africa. A core group of members attempt to monitor the breeding success of each nest annually. Activities of the group are mainly confined to the Mpumalanga Lowveld. The University of KwaZulu-Natal is undertaking research on dispersal and movements of immature birds, although this research is limited to KwaZulu-Natal.
There is an urgent need to protect remaining primary forest throughout the species' range. Conservation targets should be established, and regular monitoring, under the auspices of the Crowned Eagle Working Group, should determine the status of the whole regional population. An environmental education programme aimed at local communities should to be implemented. There needs to be increased engagement with stakeholders, including land-owners such as forest companies, as well as private individuals whose properties hold Crowned Eagle nests. A Species Management Plan may be appropriate.
* The confidence in the regional population estimate needs to be improved.
* Concurrently, surveys should aim to identify nest locations, through direct observations, interviews with land-owners, reporting programmes by bird-watchers, and perhaps aerial surveys.