Justification of Red List Category
This species has a very 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 is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size may be small, but it is not believed to 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 estimated to number 1,000-25,000 individuals, roughly equating to 670-17,000 mature individuals.
The population trend is difficult to determine because of uncertainty over the main threats to the species.
Behaviour This species is sedentary but may make local altitudinal movements within its Ethiopian range (del Hoyo et al. 1992). It breeds during the short rainy season between March and May, or in the more substantial rains of July (occasionally also breeding during the dry season in December) (del Hoyo et al. 1992). The species usually breeds colonially, although it may also nest in solitary pairs or smaller groups of 2-3 pairs (del Hoyo et al. 1992). It feeds in flocks of varying magnitudes, sometimes reaching sizes of up to 50 to 100 individuals (del Hoyo et al. 1992). Habitat The species is found in the highlands of Ethiopia between 1,500 to 4,100 m, where it inhabits river courses with rocky cliffs, and open country such as alpine moorland, swamps, cultivated land, plantations and open woodland (typically of olive, juniper and occasionally Eucalyptus stands) (del Hoyo et al. 1992). Diet Its diet is unknown, but is most likely to consist of worms and insects (such as the adults and larvae of coprophagus beetles), as well as frogs and small mammals (young mice) (Brown et al. 1982, del Hoyo et al. 1992). Breeding site When breeding colonially nests are placed on the eastern slopes of rocky cliffs (to obtain maximum morning sunlight for warmth) (Hancock et al. 1992), or on bushes protruding from cliff-faces, often up to 3,000 m in altitude (Brown et al. 1982, del Hoyo et al. 1992). When breeding in solitary pairs or small groups however, nests are more likely to be placed on the tops of trees or on ledges of buildings at lower elevations (1,800 to 2,000 m) (Brown et al. 1982, del Hoyo et al. 1992). In both cases the nest is a platform of branches and sticks (Brown et al. 1982, del Hoyo et al. 1992).
The species is currently threatened in the Bale Mountains National Park, Ethiopia, by overgrazing and tree-cutting, and is also potentially threatened by soil erosion, conversion to agriculture (farmers from the north of Ethopia have been relocated to the area) and extraction of groundwater (small scale extraction and irrigation has started and there are plans to expand the process) (Hughes 2006). The long periods of recent warfare and drought in Ethiopia also raise concerns for this species due to its very restricted range (Hancock et al. 1992).
Text account compilers
Ekstrom, J., Butchart, S., Malpas, L.
BirdLife International (2018) Species factsheet: Bostrychia carunculata. Downloaded from http://www.birdlife.org on 17/02/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/02/2018.