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African Openbill Anastomus lamelligerus
BirdLife is updating this factsheet for the 2016 Red List
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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.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Trend justification
The overall trend is decreasing, although some populations may be stable (Wetlands International 2006).

Behaviour This species is an intra-African trans-equatorial migrant (del Hoyo et al. 1992) making movements that are triggered by the rains (Hancock et al. 1992). It breeds during in the rains when snails (its main prey items) are most readily available and nests in colonies of various sizes (del Hoyo et al. 1992) often with other species (Hancock et al. 1992). Nesting may only occur in years when local food supplies are plentiful however, so may not occur regularly at the same site (Hancock et al. 1992). The species feeds in loose groups (Brown et al. 1982, Hancock et al. 1992) that may contain up to 50 well-dispersed individuals (flocks of over 7,000 may also occur in some seasons) (Hancock et al. 1992). It migrates in flocks (del Hoyo et al. 1992) and roosts communally in trees (Brown et al. 1982). Habitat The species inhabits freshwater wetlands (del Hoyo et al. 1992) with shallow waters and a large abundance of aquatic molluscs (Hancock et al. 1992) including marshes, swamps, rice-fields, flood-plains, the backwaters and margins of lakes or rivers (del Hoyo et al. 1992), ponds and streams (Hancock et al. 1992). It may also frequent moist savanna or burnt grassland as well as occasionally forest clearings (del Hoyo et al. 1992), coastal mudflats and mangrove swamps (Hancock et al. 1992). Diet In many regions the species may depend entirely upon molluscs (Hancock et al. 1992) such as aquatic snails (e.g. Pila spp. or Lanistes ovum) (del Hoyo et al. 1992) and freshwater mussels (Ampullaria spp.) (del Hoyo et al. 1992). Other prey items taken include frogs, crabs, worms, fish and insects (del Hoyo et al. 1992) (e.g. locusts and beetles) (Hancock et al. 1992). Breeding site The nest is a small platform of sticks and vegetation (del Hoyo et al. 1992) positioned in trees and bushes over water (Hancock et al. 1992, del Hoyo et al. 1992) (e.g. inundated in standing water on flood-plains) (Brown et al. 1982), or alternatively in reedbeds (del Hoyo et al. 1992). It nests colonially, often in mixed-species groups (Hancock et al. 1992).

The species is threatened by habitat loss, entanglement in fishing lines and environmental pollution (e.g. pesticides applied to water for mosquito control) (Hockey et al. 2005). It also suffers from hunting, poaching and the destruction of breeding colonies by villagers on Madagascar (Hancock et al. 1992, del Hoyo et al. 1992). Utilisation The species is hunted and traded at traditional medicine markets in Nigeria (Nikolaus 2001).

Brown, L. H.; Urban, E. K.; Newman, K. 1982. The birds of Africa vol I. Academic Press, London.

del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.

Delany, S.; Scott, D. 2006. Waterbird population estimates. Wetlands International, Wageningen, The Netherlands.

Hancock, J. A.; Kushlan, J. A.; Kahl, M. P. 1992. Storks, ibises and spoonbills of the world. Academic Press, London.

Hockey, P. A. R.; Dean, W. R. J.; Ryan, P. G. 2005. Roberts birds of southern Africa. Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa.

Nikolaus, G. 2001. Bird exploitation for traditional medicine in Nigeria. Malimbus 23: 45-55.

Further web sources of information
Explore HBW Alive for further information on this species

View photos and videos and hear sounds of this species from the Internet Bird Collection

Text account compilers
Ekstrom, J., Butchart, S., Malpas, L.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Anastomus lamelligerus. Downloaded from on 25/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 25/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Least Concern
Family Ciconiidae (Storks)
Species name author Temminck, 1823
Population size mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 13,700,000 km2
Country endemic? No
Links to further information
- Additional Information on this species
- Projected distributions under climate change