Rationale
(Changed due to Genuine (recent))
The regional population of the majestic Martial Eagle Polemaetus bellicosus is estimated at c. 800 mature individuals and is believed to be undergoing a continuous population decline of greater than 20% over a period of two generations. In addition, there appears to have been a suspected population size reduction of greater than 30% over the last three generations where the reduction or its causes may not have ceased or may not be understood or may not be reversible. For these reasons, it is listed as regionally Endangered.
Distribution
The Martial Eagle is found throughout sub-Saharan Africa, only being absent from the lowland forests of West Africa (Ferguson-Lees and Christie 2001). With the exception of Lesotho, the species is widespread in the region but is more commonly encountered in protected areas such as in the Lowveld and Kalahari (Barnes 2000). Two conservation areas, the Kruger National Park and the Kgalagadi Transfrontier Park, together hold a substantial proportion of the region's population.
Outside of protected areas in the former Transvaal, Martial Eagle territory sizes are on average between 300 and 1 000 km2 in extent; however, such territory sizes are probably not natural, and may be attributable to persecution and human-induced alteration of primary productivity (van Zyl 1992). In more natural situations, Martial Eagles still require an exceptionally large home range, in excess of 130 km2 (Brown et al. 1982). Densities in areas stocked with indigenous game are higher than in areas supporting only domestic stock, and the species is virtually absent from cultivated areas (Machange et al. 2005).
Breeding adults are thought to be sedentary; juveniles and immature birds, however, wander widely from their natal areas (Simmons 2005). The recent SABAP2 maps indicate a decrease in EoO (13.99%) while the AoO estimates show an alarming decrease of 53.47% indicating that it has not been detected in more than half of its former range. The pressure that this species is facing outside of the large protected areas is even more dramatic with reporting rates from the SABAP2 project showing large decreases or even absence from large areas of their former range. According to Parker (1999) it is scarce in neighbouring Sul do Save, southern Mozambique.
Population
The global population has not been estimated (BirdLife International 2014) although tens of thousands seems probable (Ferguson-Lees and Christie 2001). Despite this large population size, the Martial Eagle is threatened across its range and has experienced a decline in population numbers within the region (Boshoff 1997), as well as outside the region, with declines reported in Namibia (Brown 1991), southern Mozambique (Parker 1999), and possibly Zimbabwe. No regional population estimate currently exists. Figures from 1982 suggested approximately 300 mature individuals occurred in Western, Eastern and Northern Cape provinces combined (Brooke 1984). However, a survey of a single electricity pylon line of 1 400 km in the central and south-western Karoo by Machange et al. (2005) estimated 34 active Martial Eagle territories indicating that the estimate provided by Brooke (1984) was more than likely an underestimate. Although Tarboton and Allan (1984) suggested 1 000 mature individuals occurred in the former Transvaal, with 137 pairs in Kruger National Park, numbers must be much less than this today. Murn et al. (2012) estimated a breeding population of 110 mature individuals in the Kruger National Park based upon their 2011 aerial survey of nests, a decrease of at least 50%. In 1994, the Swaziland total was estimated at 40 mature individuals (Parker 1994) while more recently Monadjem and Rasmussen (2008) estimated that there were 14 mature individuals within protected areas in Swaziland representing a decline of greater than 50%. In summary, Brooke (1984) suggested a total regional population of less than 2 000 mature individuals while Barnes (2000) estimated there to be less than1 200 mature individuals in the region. Taking into account historical as well as reported decreases, the present regional population is estimated be c. 800 mature individuals. The confidence in this regional population estimate is medium.
Population trend
The global population trend is difficult to quantify but is suspected to have undergone a moderately rapid decline over the past 56 years (BirdLife International 2014). Lower reporting rates outside protected and sparsely inhabited areas suggest a dramatic decrease in densities throughout the region. Worryingly, reporting rates for large protected areas, such as Kruger National Park, also show a large decrease. The large number of checklists available for pentads in these areas means that the differences in protocol between SABAP1 and SABAP2 cannot be responsible for the consistent decrease in reporting rates. Based upon this, the decline seen in past years is probably ongoing and is believed to have been greater than 40% over the past three generations (56 years). This reduction in population size has not ceased and may not be reversible. The confidence in this regional population trend estimate is medium.
Threats
The Martial Eagle was probably the most severely persecuted raptor in the former Cape Province (Boshoff et al. 1983). Barnes (2000) attributes the main causes for the decline in numbers to activities which occurred outside of the protected areas, with the main causes being direct persecution (shooting and trapping) by small-stock farmers, indirect persecution by poisoning, drowning in sheer-walled farm reservoirs, reduction of natural prey through habitat alteration and degradation, nest site disturbance and electrocution on electricity pylons. Monadjem and Rasmussen (2008) suspected that eaglets in Swaziland, outside of protected areas, are removed from their nests and sold to traditional healers for medicinal purposes. The process of rangeland modification and degradation (primarily by overgrazing) affects eagle populations, at least indirectly by influencing the distribution, abundance, and accessibility of prey (Machange et al. 2005). Habitat transformation is only likely to increase and as a result this species may become even more restricted to large protected areas in the future.
Conservation
Underway
The Martial Eagle is listed as Vulnerable under the National Environmental Management: Biodiversity Act (Act 10 of 2004) and under the Swaziland Game Act of 1991. The species is the focus of a range of projects and initiatives of the Endangered Wildlife Trust's Birds of Prey Programme. The Kalahari Raptor Project has used the species as one of its flagship species in creating greater awareness for the need to conserve this and other raptors in the southern Kalahari for almost 25 years. The Platberg Karoo Raptor Project has fulfilled the same function in the Eastern Karoo since 2002. The Northern Cape Raptor Conservation Forum acknowledges land-owners who have active nests of this species on their property and provides information on how to conserve such sites to the benefit of the birds. Regular surveys are undertaken of pairs nesting on infrastructure associated with transmission power-lines and cell-phone towers in the Karoo. Data of nesting sites throughout the species' range is used to advise Eskom concerning the routing of power-lines via the Endangered Wildlife Trust's Wildlife Energy Programme. The Lowveld/Kruger National Park Large Bird Project includes this species in its annual aerial survey of the Kruger National Park and is in the process of obtaining a reliable estimate of the breeding population of this species in the Lowveld. So far, these initiatives seem inadequate to reverse the population decline. The Martial Eagle is listed under Schedule 2: Specially Protected Wild Animal under the Limpopo Environmental Management Act No 7 of 2003.
Proposed
A Population and Habitat Viability Assessment (PHVA) is recommended, as is a Biodiversity Management Plan, culminating in a National Species Recovery Plan. Conservation interventions required include adequately enforcing protection of breeding sites outside of the protected area network via land-use agreements. Regular monitoring of the species is required in order to more accurately determine the regional population and conservation status. Implementation of an awareness programme involving land-owners and local communities to highlight the threats facing this species is recommended.
Research
* An investigation into the potential causes of declines within protected areas, with a focus on post-fledging dispersal and foraging range of immature birds, should be undertaken.
* Genetic studies to model regional relationships between populations/individuals and assess the roles of immigration and emigration with surrounding countries is required.
