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 ten years or three generations). The population size is very 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 ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The population is suspected to be in decline owing to ongoing habitat destruction.
Behaviour This species is an intra-African trans-equatorial migrant (Brown et al. 1982, del Hoyo et al. 1992), making seasonal movements to coincide with rainfall (Brown et al. 1982, del Hoyo et al. 1992, Hockey et al. 2005). After breeding in the wet season of the northern tropics (between May and August), it moves east then south (West African populations), or south (East African populations), through the equatorial rain-belt (September-October), and arrives in the southern tropics early in the southern wet season (November-March) (Brown et al. 1982). It remains in this southern range until March (when the rains decrease), after which it moves north again through East Africa at the beginning of the long rains (March-April), arriving back in the breeding grounds in April and May before (or just as) the heavy rains begin (Brown et al. 1982). The species is gregarious and is rarely seen in groups of less than 10 (Brown et al. 1982), often traveling in vast flocks of c.10,000 (del Hoyo et al. 1992). On migration it lands daily to feed (del Hoyo et al. 1992), both migrating and foraging diurnally (Brown et al. 1982). It breeds in widely-scattered colonies, normally not exceeding 20 pairs (Brown et al. 1982) (although groups of between 30 and 50 are recorded occasionally) (Hancock et al. 1992, Adjakpa 2000). Habitat The species frequents open grassland, pastures, areas of cultivation (Brown et al. 1982, del Hoyo et al. 1992) and savanna woodland (Hockey et al. 2005), often near water but also in semi-arid areas, gathering beside pools, water-holes, wells and swamps when not feeding (Brown et al. 1982), and roosting on trees or cliffs (Brown et al. 1982, del Hoyo et al. 1992). Diet The species is primarily insectivorous (Hancock et al. 1992), its diet consisting almost entirely of large grassland insects such as swarming locusts, army worm Spodoptera exempta caterpillars, grasshoppers and crickets, although it will also take mice (Brown et al. 1982, Hancock et al. 1992, del Hoyo et al. 1992), frogs, lizards, small fish, molluscs, crabs (Brown et al. 1982, Hancock et al. 1992), millipedes, scorpions, water rats and small birds (Hancock et al. 1992, Hockey et al. 2005). Breeding site The species breeds colonially, with nests being built from sticks and vegetation in trees or on cliffs, or on the roofs of huts in villages, and will often be used from year to year unless they collapse (although not necessarily by the same breeding pair) (Brown et al. 1982).
The species is potentially threatened by habitat degradation through urban development and agricultural activities (such as maize farming) which have reduced the available area of natural grassland (Harrison et al. 1997). In Namibia it is threatened by habitat degradation through overgrazing and bush encroachment (Harrison et al. 1997). The species may also be threatened by the control of its principle food source, locusts, either through direct poisoning (Hancock et al. 1992, Harrison et al. 1997) (a mass mortality event in Sudan may have been the result of extensive use of pesticides) (Coulter et al. 1989), or through a reduction in the availability of food (Hancock et al. 1992, Harrison et al. 1997). Utilisation The species is hunted and traded at traditional medicine markets in Nigeria (Nikolaus 2001).
Text account compilers
Ekstrom, J., Butchart, S., Malpas, L.
BirdLife International (2019) Species factsheet: Ciconia abdimii. Downloaded from http://www.birdlife.org on 19/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/11/2019.