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). The population trend appears to be increasing, and hence the species does not 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 increasing as ongoing habitat degradation is creating new areas of suitable habitat.
Behaviour This species is predominantly sedentary, although it may make local nomadic movements in response to rainfall during periods of drought (del Hoyo et al. 1992, Hockey et al. 2005). It forages diurnally in pairs or small groups of between 5 and 30individuals (del Hoyo et al. 1992) (occasionally in groups of 50-200) (Hancock et al. 1992, del Hoyo et al. 1992), and roosts nightly in groups of up to 100 (Hancock et al. 1992, del Hoyo et al. 1992). It often uses the same roost site year-round, year after year, although it will wander several kilometres away to forage during the day (Hancock et al. 1992, del Hoyo et al. 1992). The species breeds in solitary pairs (del Hoyo et al. 1992), with breeding reaching a peak during or just after the rainy season (although in Gambia and Tanzania breeding is restricted to the dry season) (del Hoyo et al. 1992). Habitat This species inhabits wooded streams and river courses in open moist grassland and savanna woodland (Brown et al. 1982, del Hoyo et al. 1992), and is attracted to man-made irrigated habitats (Hancock et al. 1992), such as cultivated land, large gardens and playing fields (del Hoyo et al. 1992, Hockey et al. 2005). It less often occurs in marshes, flooded grassland, the edges of lakes and reservoirs, mangrove swamps, coastal beaches (Brown et al. 1982, del Hoyo et al. 1992), open woodland and at forest edges (del Hoyo et al. 1992). Diet This species is carnivorous, its diet consisting largely of insects (especially weevils, Diptera, the pupae of Lepidoptera and the larvae of Coleoptera), as well as crustaceans, millipedes, centipedes, spiders, earthworms, snails and small reptiles (del Hoyo et al. 1992). Breeding site The nest is a basket-shaped platform of sticks and twigs situated 1-12 m (usually 3-6 m) above the ground or above water on a horizontal tree branch, in bushes or on man-made structures such as telegraph poles (Brown et al. 1982, del Hoyo et al. 1992), dam walls or pergolas (Hockey et al. 2005). The same nest site is usually used year after year (but not necessarily by the same breeding pair) (Brown et al. 1982).
The species is threatened by extended droughts (which reduce food availability by causing damp soil to harden, making it more difficult to probe for insects) (Hancock et al. 1992). The population in South Africa declined markedly at the turn of the century due to hunting during colonial expansion (del Hoyo et al. 1992). 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 (2021) Species factsheet: Bostrychia hagedash. 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.