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.
In Europe, the breeding population is estimated to number 81,200-109,000 breeding pairs, equating to 162,000-218,000 mature individuals (BirdLife International 2015). Europe forms approximately 11% of the global range, so a very preliminary estimate of the global population size is 1,470,000-1,980,000 mature individuals, although further validation of this estimate is needed. It is placed in the band 1,000,000-2,499,999 mature individuals.
Despite being possibly the most common raptor in the world, the population has declined owing to poisoning, shooting, pollution of water and over-use of pesticides. Modernisation of urban environments and agricultural improvements are also thought to be causing declines locally (Ferguson-Lees and Christie 2001). In Europe the current population trend direction is unknown (BirdLife International 2015). Outside Europe the overall trend is unclear, with some countries (e.g. Australia) reporting increases and others decreases (e.g. Zambia) (Global Raptors Information Network 2015). However Thiollay (2007) detected a significant decline in West Africa of approximately 70% outside protected areas between 1969-1973 and 2000-2004.
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 migrating 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 4,000 m in the Himalayas (del Hoyo et al. 1994). 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 has suffered historically as a result of poisoning, shooting and the pollution of water by pesticides and other chemicals (Orta et al. 2015). Agricultural pesticide poisoning caused its extirpation as a breeder in Israel in the 1950s; it has since recolonised (del Hoyo et al. 1994). Carcass poisoning and water pollution continues to drive declines in Europe and parts of Asia. Whilst it is well-suited to the presence of humans, particularly in terms of its diet, the modernisation of cities has been shown to reduce available habitat, with overall Black Kite populations showing declines through the 20th century in Delhi and Istanbul (Ferguson-Lees and Christie 2001). In its West African range, the species is vulnerable to habitat degradation through wood harvesting and overgrazing as well as exposure to pesticides (Thiollay 2007). It is very highly vulnerable to the effects of potential wind energy development (Strix 2012).
Text account compilers
Calvert, R., Khwaja, N. & Ashpole, J
BirdLife International (2020) Species factsheet: Milvus migrans. Downloaded from http://www.birdlife.org on 04/12/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/12/2020.