Justification of Red List category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over 10 years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in 10 years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
There are no estimates of the global population size of the species. Parker (2005) estimated 1,000 birds to be present, presumably breeding in central Mozambique. The abundance of the species in much of sub-Saharan Africa indicates that the population is likely to be very large. In the Western Cape a rapid increase has been recorded between the 1950s and 1960s and 1997-1998 (Herremans and Herremans-Tonnoeyr 2001), but in other parts of the range a rapid reduction in the numbers detected during driven transects has been reported (Thiollay 2007; Garbett et al. 2018). While there is little solid data, it is suspected that the population is slowly declining.
Despite probably being the commonest large raptor in Africa the population is suspected to have declined, most likely due to poisoning, shooting, pollution of water and over-use of pesticides. Thiollay (2007) reported declines in observations from driven transects of 70% between 1969-73 and 2000-2004. In Botswana, a partial repeat in 2015 of road transects carried out in 2000 returned a non-significant decline of 28% for Yellow-billed Kite (Garbett et al. 2018). However, in the Western Cape, a dramatic increase was recorded from similar paired road transect surveys comparing those driven in the 1950s and 1960s to repeats in 1997-98 (Herremans and Herremans-Tonnoeyr 2001). Overall, a slow population reduction is suspected.
The species occurs virtually throughout sub-Saharan Africa, the Comoro Islands and Madagascar, and from coastal east Africa to Egypt and the south west Arabian Peninsular. Estimates of population size are largely lacking, but the species is considered to be likely the most abundant diurnal raptor in Africa (Orta et al. 2020). While birds may be present in almost the entire range at almost any time of year (eBird 2020), there are clear movements of migratory breeders to the south in the austral summer, reaching southernmost points in August-September (Global Raptor Information Network 2020). In west Africa, most individuals arrive towards the end of the rainy season (Global Raptor Information Network 2020), but again birds are often observed throughout the year (eBird 2020).
Behaviour The species is mainly migratory, with birds from Europe and northern Asia wintering in sub-Saharan Africa and southern Asia. Those at lower latitudes do not tend to be full migrants (del Hoyo et al. 1994). Migrating birds leave their breeding grounds between July and October, arriving back between February and May (Ferguson-Lees and Christie 2001). It is generally a gregarious species, with birds often roosting communally and observed in scattered flocks (del Hoyo et al. 1994; Ferguson-Lees and Christie 2001). Habitat It is found ubiquitously throughout habitats, although avoiding dense woodland, and is recorded foraging up to 2,400 m in Malawi (Global Raptor Information Network 2020). Diet An extremely versatile feeder, it takes carrion as well as live birds, mammals, fish, lizards, amphibians and invertebrates, and is even known to forage on vegetable matter such as palm oil fruits; human refuse has become a plentiful food source in many areas (del Hoyo et al. 1994). Breeding site The nest is usually built on the fork or branch of a tree (del Hoyo et al. 1994). Management information The species has become highly commensal with people and thrives in human-dominated environments, but modernisation of cities appears to reduce its breeding success (del Hoyo et al. 1994; Ferguson-Lees and Christie 2001).
The species is suspected to be declining in common with a other scavenging birds in sub-Saharan Africa (Virani et al. 2011), and is likely to be impacted by poisoning (e.g. carcass poisoning or through ingestion of lead shot), shooting and the pollution of water by pesticides and other chemicals (Thiollay 2007; Orta et al. 2015). It is possible that the species suffers excess mortality due to poorly sited energy infrastructure, but the extent to which this may be impacting populations of this species is uncertain but thought likely negligible: the species does not concentrate in migratory bottlenecks as do related species.
Repeated monitoring of scavenging birds is required throughout sub-Saharan Africa to improve the ability to detect declines.
Text account compilers
BirdLife International (2023) Species factsheet: Milvus aegyptius. Downloaded from http://datazone.birdlife.org/species/factsheet/yellow-billed-kite-milvus-aegyptius on 30/11/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 30/11/2023.