Justification of Red List Category
This species is listed as Endangered because it is suspected to have undergone very rapid declines during the past three generations (33 years) owing to deliberate and incidental poisoning, habitat loss, reduction in available prey, pollution and collisions with power lines; threats that are likely to continue this trend into the future.
The global population has not been quantified, but was estimated as probably 'in tens of thousands' by Ferguson-Lees and Christie (2001). The population in South Africa, Lesotho and Eswatini is believed to be c.800 pairs (Taylor 2015); the population in Namibia is estimated at <350 pairs (Simmons 2015). In Ethiopia, raptor road-count surveys between 2010-2017 had a Martial Eagle observation rate of 0.00055 individuals/km (E. Buechley in litt. 2020). Martial Eagles are still widespread and frequently observed in Malawi (S. Chihana in litt. 2020), and Tanzania (N. Baker in litt. 2020).
Declines have taken place across much of this species's range owing to habitat loss, deliberate and incidental poisoning, collisions with power lines, and pollution. Surveys across Mali, Burkina Faso and Niger detected a reduction in the observation rate in unprotected areas from 0.8 to 0 birds/100 km, and a reduction in the observation rate in National Parks from 1.4 to 0.7 birds/100 km (Thiollay, 2006). These rates of reduction are equivalent to a 100% reduction in unprotected areas and a 51% reduction in National Parks when scaled across three generations. Similarly in Botswana, Garbet et al., (2018) reported a reduction in observation rates from 0.14 to 0.09 birds/100 km, which after controlling for variations in transect survey lengths and distributions equates to a rate of decline of 67% over three generations. In Kenya, surveys detected a 65% reduction in the observation rate in unprotected areas (from 0.23 to 0.08 birds/100 km) and a 133% increase in the observation rate in protected areas (from 0.53 to 1.24 birds/100 km; Ogada et al., in prep. a). These rates of reduction would equate to a 58% reduction in unprotected areas and a 102% increase in protected areas over three generations. Analysis of reporting rates for South Africa from the Southern African Bird Atlas Project (SABAP) 1 (1987–1992) and SABAP 2 (2007–2012) also found a 59% reduction in mean reporting rate (from 7.3% in SABAP 1 to 3.0% in SABAP 2; Amar & Cloete, 2018). Scaled across three generations, this rate of change would equate to a reduction of 77%. The overall rate of decline is difficult to quantify but is suspected to have been very rapid over the past three generations (33 years). It is consequently placed in the band 50-79%.
Polemaetus bellicosus has an extensive range across much of sub-Saharan Africa, from Senegal and the Gambia east to Ethiopia and north-west Somalia, and south to Namibia, Botswana and South Africa. It is generally scarce to uncommon or rare, but is reasonably common in some areas (Ferguson-Lees and Christie 2001). It is suspected to have undergone declines in much of its range, including west Africa (Thiollay 2006, H. Rainey in litt. 2013), Namibia (C. Brown in litt. 2009), Nigeria (P. Hall in litt. 2009), Kenya (S. Thomsett in litt. 2013) and South Africa (Amar and Cloete 2018).
It inhabits open woodland, wooded savanna, bushy grassland, thornbush and, in southern Africa, more open country and even subdesert, from sea level to 3,000 m but mainly below 1,500 m (Ferguson-Lees and Christie 2001). The main prey is sizeable mammals, birds and reptiles (Ferguson-Lees and Christie 2001). In Kenya's Maasai Mara, average pair territory size is approximately 175 km2, and evidence suggests that breeding pairs select strongly against human-disturbed habitats (R. Hatfield in litt. 2020). In South Africa, 138 active Martial Eagle nests have been found along 1,750 km of power lines, suggesting the pylons provide artificial nesting sites, although this species remains extremely vulnerable to power line related fatalities (G. Tate in litt. 2020).
The species suffers from direct persecution (shooting and trapping) by farmers, indirect poisoning (these two threats by far the most important causes of losses), drowning in sheer-walled reservoirs, electrocution on power lines, habitat alteration and degradation (Global Raptor Information Network 2009), and nest disturbance (JM Thiollay pers. comm. 2020). Poisoning is largely carried out by a few large-scale commercial farmers, but is also a problem in tribal small-stock farming communities. Incidences of targeted poisoning in retaliation for the predation of domestic livestock have been recorded in Kenya (R. Hatfield in litt. 2020). Deforestation may be having less of an impact on this species than on other large eagles, as this species can utilise man-made structures for nesting. In west Africa, it is also threatened by a decline in suitable prey through over-hunting (JM Thiollay pers. comm. 2020). Large mammal populations in west Africa are highly threatened, and the threats are likely to increase in the future as human populations continue to grow. (H. Rainey in litt. 2013). Reduction in natural prey may lead to an increase in predation on domestic animals, which may in turn lead to increased persecution by farmers. In some areas, birds may be taken for use in traditional medicine, and parts have been found in muthi markets in Johannesburg (R. Coetzee in litt. 2013). The majority of protected areas in Kenya are too small to hold a single pair (S. Thomsett in litt. 2013), and the size of territory means that birds nesting in protected areas will generally forage far outside them, making them more vulnerable to persecution. In South Africa, the highest declines were observed in areas with the greatest increase in temperature and areas with high densities of power lines, probably due to collisions and electrocutions. In Kruger National Park, higher densities of elephants were related to larger declines in Martial Eagles, probably as a result of a reduction in nesting sites or changes in habitat quality (Cloete 2013, R. van Eeden in litt. 2013). Between 2013-2020, breeding success rate in the Kruger National Park has been poor (M. Murgatroyd in litt. 2020). The species can use power pylons as nesting sites, which can lead to power outages, and so create human-wildlife conflict (Jenkins et al. 2013).
Conservation Actions Underway
A system to compensate farmers for stock losses has been initiated in South Africa. The species is listed as Endangered in Namibia, South Africa, Lesotho and Eswatini (Simmons 2015, Taylor 2015).
Text account compilers
Amar, A., Baker, N., Brown, C., Buechley, E., Butchart, S., Chihana, S., Cloete, D., Coetzee, R., Ekstrom, J., Hall, P., Harding, M., Hatfield, R., Murgatroyd, M., Ogada, D., Rainey, H., Shaw, P., Symes, A., Thiollay, J.-M., Thomsett, S., Westrip, J.R.S. & van Eeden, R.
BirdLife International (2021) Species factsheet: Polemaetus bellicosus. Downloaded from http://www.birdlife.org on 25/02/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/02/2021.