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 threshold for Vulnerable under the population trend criterion (>30% decline over ten years of 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 species has a large global population estimated to be 200,000-510,000 individuals (Wetlands International 2006). Although uncommon over most of its range, it is regarded as common in Gabon and Congo (Borrow and Demey 2001)
The species is tentatively assessed as being in decline due to habitat loss per Tracewski et al. 2016.
This species is widespread in west African lowland forests from Liberia east to the Democratic Republic of Congo and Uganda.
The species frequents forested streams and wooded swamps, always above or near water, in lowland forest (del Hoyo et al. 1992). The same trees are used for roost sites year-round. It feeds on aquatic snails, worms, beetles, larvae and grubs, which it probes for in muddy banks and swamps. Nests are situated 1-6 m above the ground or overhanging water, and comprise a circular platform on top of several lateral tree branches, approximately 30 cm across. Two eggs are usually laid (Brown et al. 1982). The species is sedentary (del Hoyo et al. 1992), with individuals remaining in an area all year and using traditional roosting sites for sleeping (Hancock et al. 1992). It is likely to breed for most of the year (del Hoyo et al. 1992), especially during periods of peak rainfall (Hancock et al. 1992), but it does not breed during the long dry season when water levels are lowest (del Hoyo et al. 1992). The species nests in solitary pairs and forages singly or in pairs throughout the year (del Hoyo et al. 1992), small groups (e.g. 5-8 birds in same tree) often congregating at roosting sites to sleep (Brown et al. 1982, del Hoyo et al. 1992). It is diurnally active, although it may also forage at night (especially in bright moonlight) (Brown et al. 1982, del Hoyo et al. 1992. The species is carnivorous, its diet consisting of beetles, larvae, grubs, aquatic snails and worms (Brown et al. 1982, Hancock et al. 1992, del Hoyo et al. 1992).
Intense forest destruction in West Africa is probably the main threat to this species (del Hoyo et al. 1992). Fishermen in Gabon are known to take nestlings from the nests of this species .
Text account compilers
Butchart, S., Harding, M., Fisher, S., Ekstrom, J.
BirdLife International (2022) Species factsheet: Bostrychia rara. Downloaded from http://www.birdlife.org on 26/11/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/11/2022.