Justification 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 extremely 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.

Family/Sub-family Ardeidae

Species name author (Linnaeus, 1758)

Taxonomic source(s) AERC TAC (2003), AOU checklist (1998 + supplements), Christidis and Boles (1994), Christidis and Boles (2008), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), SACC (2005 + updates), Sibley and Monroe (1990, 1993), Stotz et al. (1996), Turbott (1990)

Synonyms Ardea ibis Christidis and Boles (2008), Ardeola ibis Stotz et al. (1996)

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

3,800,000 - 7,600,000

unset

62,700,000 km²

No

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: Behaviour Most populations of this species are partially migratory, making long-distance dispersive movements related to food resources in connection with seasonal rainfall¹. Other populations (e.g. in north-east Asia and North America) are fully migratory^{1, 5}. The species breeds throughout the year in the tropics with different regional peaks¹ depending on food availability². It breeds colonially, often with other species, in groups that number from a few dozen to several thousand pairs, even up to 10,000 pairs in Africa¹. The nesting effort of the species is related to rainfall patterns, leading to an annual variation in productivity². Outside of the breeding season the species remains gregarious^{1, 4}, feeding in loose flocks of 10-20 individuals⁴ and often gathering in flocks of hundreds or even thousands of individuals where food is abundant¹. Nocturnal roosting sites in Africa commonly hold a few hundred to 2,000 individuals⁴. The species is a diurnal feeder¹ and commonly associates with native grazing mammals or domesticated livestock² and may follow farm machinery to capture disturbed prey¹. Habitat The species inhabits open grassy areas such as meadows¹, livestock pastures², semi-arid steppe¹ and open savanna grassland subject to seasonal inundation², dry arable fields¹, artificial grassland sites (e.g. lawns, parks, road margins and sports fields)², flood-plains³, freshwater swamps, rice-fields, wet pastures¹, shallow marshes², mangroves³ and irrigated grasslands (with ponds, small impoundments, wells, canals, small rivers and streams)². It rarely occupies marine habitats or forested areas¹ although in Australia it may enter woodlands and forests, and it shows a preference for freshwater⁶ although it may also use brackish or saline habitats². It occurs from sea-level up to c.1,500 m² or locally up to c.4,000 m (Peru)¹. Diet Its diet consists primarily of insects such as locusts, grasshoppers¹, beetles, adult and larval Lepidoptera, Hemiptera, dragonflies³ and centipedes but worms⁴, spiders³, crustaceans, frogs, tadpoles, molluscs, fish, lizards, small birds, rodents and vegetable matter (e.g. palm-nut pulp) may also be taken¹. Breeding site The nest is constructed of twigs and vegetation² and is positioned up to 20 m high in reedbeds^{1, 2}, marshes, mangroves, dense thickets², bushes or trees^{1, 2}, usually over or surrounded by water². The species nests colonially in single- or mixed-species groups with the nests placed close or touching⁵. Management information The species can adversely affect the trees and bushes it uses for nesting, which may lead to the abandonment of the colony site if it is not managed².

Threats Large colonies nesting in urban areas are perceived as a public nuisance and may be persecuted (e.g. by disturbance to prevent colony establishment, removal or direct killing)². In its breeding range the species is threatened by wetland degradation and destruction such as lake drainage for irrigation and hydroelectric power production (Armenia)⁹, and in some parts of its range it is susceptible to pesticide poisoning (organophosphates and carbamates)⁸. Utilisation The species is hunted and traded at traditional medicine markets in Nigeria⁷.

References 1. del Hoyo et al. (1992). 2. Kushlan and Hancock (2005). 3. Hancock and Kushlan (1984). 4. Brown et al. (1982). 5. Snow and Perrins (1998). 6. Marchant and Higgins (1990). 7. Nikolaus (2001). 8. Kwon et al. (2004). 9. Balian et al. (2002).

Further web sources of information

Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

Text account compilers Stuart Butchart (BirdLife International), Jonathan Ekstrom (BirdLife International), Lucy Malpas (BirdLife International)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International)

Recommended citation BirdLife International (2010) Species factsheet: Bubulcus ibis. Downloaded from http://www.birdlife.org on 6/9/2010

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

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