Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Bubulcus ibis
(cattle egret)



Bubulcus ibis (cattle egret)


  • Last modified
  • 20 November 2019
  • Datasheet Type(s)
  • Invasive Species
  • Threatened Species
  • Natural Enemy
  • Host Animal
  • Preferred Scientific Name
  • Bubulcus ibis
  • Preferred Common Name
  • cattle egret
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Chordata
  •       Subphylum: Vertebrata
  •         Class: Aves
  • Summary of Invasiveness
  • Bubulcus ibis are small stocky herons that associate with grazing species of mammals both domestic and wild. They have strong migratory instincts and disperse thousands of miles in the direction of their choosing. They are, for the most par...

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Bubulcus ibis (cattle egret); adult flying, with nesting material. Dallas, Texas, USA. June, 2011.
CaptionBubulcus ibis (cattle egret); adult flying, with nesting material. Dallas, Texas, USA. June, 2011.
Copyright©Manjith Kainickara/via wikipedia - CC BY-SA 2.0
Bubulcus ibis (cattle egret); adult flying, with nesting material. Dallas, Texas, USA. June, 2011.
AdultBubulcus ibis (cattle egret); adult flying, with nesting material. Dallas, Texas, USA. June, 2011.©Manjith Kainickara/via wikipedia - CC BY-SA 2.0
Bubulcus ibis (cattle egret); adult, foraging. Morey, Texas, USA. June, 2007.
CaptionBubulcus ibis (cattle egret); adult, foraging. Morey, Texas, USA. June, 2007.
Copyright©Rick Kimpel/via wikipedia - CC BY-SA 2.0
Bubulcus ibis (cattle egret); adult, foraging. Morey, Texas, USA. June, 2007.
AdultBubulcus ibis (cattle egret); adult, foraging. Morey, Texas, USA. June, 2007.©Rick Kimpel/via wikipedia - CC BY-SA 2.0


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Preferred Scientific Name

  • Bubulcus ibis (Linnaeus, 1758)

Preferred Common Name

  • cattle egret

Other Scientific Names

  • Ardea ibis
  • Ardeola ibis
  • Bulbucus ibis

International Common Names

  • English: buff-backed heron; egret, cattle; elephant bird; hippopotomus egret; Indian cattle egret; rhinoceros egret
  • Spanish: depulgabuey; garcilla bueyera; garcilla garrapatera; garcita de ganado; garrapatera; garrapatosa; garza de ganado; garza de vaquèra; garza ganadera
  • French: héron garde-boeufs

Local Common Names

  • Netherlands: Afrikaanse koereiger

Summary of Invasiveness

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Bubulcus ibis are small stocky herons that associate with grazing species of mammals both domestic and wild. They have strong migratory instincts and disperse thousands of miles in the direction of their choosing. They are, for the most part, self-introduced. They have been observed 'feeding on' native species of birds. They are known to host ticks that could introduce and spread certain tick-borne diseases.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Chordata
  •             Subphylum: Vertebrata
  •                 Class: Aves
  •                     Order: Ciconiiformes
  •                         Family: Ardeidae
  •                             Genus: Bubulcus
  •                                 Species: Bubulcus ibis


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Cattle egrets (Bubulcus ibis) are relatively small, stocky herons, with thick short necks (shorter than body), completely white in colour, except when breeding, at which time they are adorned by orange buff plumes on their crown, back and foreneck. The bill is yellow with a heavy jowl of feathers underneath and the legs are yellow to green and the eyes are light yellow when not breeding. During the breeding season the bill and legs are pink to orange-red and the eyes become a shade of bright red and the lores become purple-pink. Juveniles have black bills. Males and females typically grow to between 51-56cm in length and weigh around 360g (Birds of New Zealand, 2005; Cornell Lab of Ornithology, 2003; and GSMFC, 2005).


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Native range: Africa, Asia, and Europe (Marion et al. 1993; and GBIF, 2006).
Known introduced range: Australasia-Pacific, North America, South America (Birds of New Zealand, 2005; Bergman et al. 2000; and Bella and Azevendo, 2004).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Last updated: 10 Feb 2022
Continent/Country/Region Distribution Last Reported Origin First Reported Invasive Reference Notes


South AfricaPresentNative


South Georgia and the South Sandwich IslandsPresentIntroduced2005


British Indian Ocean Territory
-Chagos ArchipelagoPresentIntroduced1953
-Andhra PradeshPresent


Serbia and MontenegroPresentNative
United KingdomPresentPresent based on regional distribution.

North America

Dominican RepublicPresentIntroduced
El SalvadorPresentIntroduced2003
Netherlands AntillesPresentIntroduced
Puerto RicoPresentIntroduced
Saint LuciaPresentIntroducedInvasiveSafety hazard at Hewanorra Airport due to bird strike risk
Trinidad and TobagoPresentIntroduced1981
Turks and Caicos IslandsPresentIntroducedInvasive
U.S. Virgin IslandsPresentIntroduced2005
United StatesPresentPresent based on regional distribution.


New ZealandPresentIntroduced

South America

Falkland IslandsPresentIntroduced1996


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Cattle egrets (Bubulcus ibis) are common around marshes, farms, highway edges, pastures, ploughed fields and other altered habitats. They are strongly migratory and juveniles may disperse thousands of miles in random directions (GSMFC, 2005).

Habitat List

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Terrestrial ManagedCultivated / agricultural land Present, no further details Harmful (pest or invasive)
Terrestrial ManagedDisturbed areas Present, no further details Harmful (pest or invasive)
Terrestrial ManagedUrban / peri-urban areas Present, no further details Harmful (pest or invasive)
Terrestrial Natural / Semi-naturalWetlands Present, no further details Harmful (pest or invasive)
BrackishEstuaries Present, no further details Harmful (pest or invasive)

Biology and Ecology

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Cattle egrets (Bubulcus ibis) are opportunistic feeders and typically forage in flocks often associated with grazing animals and pick off parasites on the large herbivores. They may also follow tractors or lawnmowers waiting for insects and other prey items that are flushed out. They feed mostly on relatively large insects, especially grasshoppers, crickets, flies and moths as well as spiders, frogs, crayfish, earthworms, snakes and rarely also fish, birds eggs and even nestling birds. B. ibis also scavenge for edible refuse in garbage dumps. Egrets will fly long distances to catch insects trying to escape fire (Cornell Lab of Ornithology, 2003; and GSMFC, 2005).

GSMFC (2005) reports that, "Bubulcus ibis are promiscuous, with males frequently engaging in extra-pair copulation. They begin to breed at age two or three (Kaufman, 1996). Cattle egrets are colonial breeders, and are frequently found in mixed colonies with other species of herons and egrets. Males establish pairing territories within the colonies and carry out elaborate displays for females. Nests are typically built in aquatic habitats in trees or shrubs of swamps or islands. Nesting materials typically include reeds, shrubs and elder twigs. Males bring most of the material for the nests and females build the nests. Nests are platforms or shallow bowls often with protruding green leafy twigs. Nest building and mating usually lasts three days. Immediately following mating, cattle egrets begin to lose their breeding colours."

Lifecycle stages
Cattle egret (Bubulcus ibis) clutches vary from 1 to 9 pale blue eggs, but typically consist of 3 to 4 eggs. The incubation period can last between 21 and 26 days. Depending on food availability, of the three to four eggs laid, usually only one or two are raised successfully, with later hatching chicks at a decided disadvantage. Young begin to fly in 25-30 days and become independent after about 45 days. B. ibis often nest in colonies with other egrets. Nests are in trees and three white eggs are laid. Both adults incubate and feed chicks by regurgitation. Youngsters scramble onto nearby branches as early as two weeks but do not fly until six or seven weeks of age (Birds of New Zealand, 2005; and GSMFC, 2005).

Means of Movement and Dispersal

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Introduction pathways to new locations
Natural dispersal: The cattle egret Bubulcus ibis is able to disperse thousands of kilometers in a matter of days through its own migrational patterns and instincts (CAST, 2002).

Pathway Causes

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CauseNotesLong DistanceLocalReferences
Self-propelled Yes Yes

Impact Summary

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Native fauna Negative


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General Impacts

Compiled by IUCN SSC Invasive Species Specialist Group (ISSG)
Cattle egrets are able to thrive in areas densly populated by other species, and this makes them potentially able to over-crowd and out-comepete native birds for nesting areas. A number of articles point out however, that cattle egrets seem to have little or no impact on native bird species they live with. They are known to nest next to and amongst native birds with little or no observable conflict occuring, and because their nesting time is after native Herons, this further reduces threat of competition. Lastly, their diet, which is mostly insects and land invertebrates, does not overlap with native Heron's diets, which are fish and aquatic invertebrates. (GSMFC, 2005)

Risk and Impact Factors

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  • Proved invasive outside its native range
  • Highly adaptable to different environments
  • Capable of securing and ingesting a wide range of food
  • Highly mobile locally
Impact outcomes
  • Threat to/ loss of native species
Impact mechanisms
  • Competition - monopolizing resources
  • Pest and disease transmission
  • Predation


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Some ranchers rely on cattle egrets (Bubulcus ibis) for fly control more than they do pesticides (Ivory, 2000).

Similarities to Other Species/Conditions

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Ardea alba
The great egret (Ardea alba) also has dark legs and a yellow bill like the cattle egret (Bubulcus ibis), but is much taller and longer necked (Cornell Lab of Ornithology, 2003).

Egretta caerulea
The white juvenile of the little blue heron (Egretta caerulea) has greenish legs, and a dark bill with a bluish base (Cornell Lab of Ornithology, 2003).

Egretta thula
The snowy egret, Egretta thula is slimmer, has a black bill, and yellow feet as opposed to adult cattle egrets Bubulcus ibis which have a yellow bill and yellow-green or pink legs. The legs and wings of snowy egrets are also relatively longer and the wing beat, when flying, is slower (GSMFC, 2005; Cornell Lab of Ornithology, 2003).


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Bella, S. M., and S. M. Azevendo. 2004. Consideracoes sobre a ocorrencla da garca-vaqueira, Bubulcus ibis (Linnaeus) (Aves, Ardeidae), em Pernambuco, Brasil. Revista Brasileira de Zoologia 21(1):57-63.

Bergman, D. L., M. D. Chandler, and A. Locklear. 2000. The Economic Impact of Invasive Species to Wildlife Services Cooperators. Uman Conflicts with Wildlife Economic Considerations.

Birds of New Zealand. 2005. Cattle egret. New Zealand Birds Limited: Greytown, New Zealand.

Botkin, D. B. 2001. The Naturalness of Biological Invasions. Western North American Naturalist 61(3), pp. 261-266.

CAST (Council for Agricultural Science and Technology). 2002. Invasive Pest Species Impacts on Agricultural Production, Natural Resources, and the Environment. Issue Paper 20, March 2002.

CONABIO. 2008. Sistema de información sobre especies invasoras en México. Especies invasoras - Aves. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad. Fecha de acceso.

Cornell Lab of Ornithology. 2003. Cattle Egret. All About Birds Online Guide.

Global Biodiversity Information Facility (GBIF), 2005. Species: Bubulcus ibis (Linnaeus, 1758)

Goutner, V., H. Jerrentrup, S. Kazantzidis, and T. Nazirides. 1991. Occurrence of the cattle egret, Bubulcus ibis, in Greece. Rivista Italiana di Ornitologia. 61(3-4). 107-112.

Gulf States Marine Fisheries Commission (GSMFC), 2005. Bubulcus ibis (Linnaeus, 1758). University of Southern Mississippi/College of Marine Sciences/Gulf Coast Research Laboratory.

Heather, B. D. 1980. The Cattle Egret Bubulcus ibis in New Zealand 1978-1980. Source Notornis. 29(4). 1982. 241-268.

Ivory, A. 2000. Bubulcus ibis. (On-line), Animal Diversity Web.

Jaksic, F.M. 1998. Vertebrate invaders and their ecological impacts in Chile. Biodiversity and Conservation 7, 1427±1445 (1998).

Jandres, M. V. 2002. Diagnóstico de las especies invasoras de fauna vertebrada y sus efectos sobre ecosistemas en El Salvador. Ministerio de Medio Ambiente y Recursos Naturales.

Krebs, E. A., D. R. Ramsey, and W. Hunte. 1994. The colonization of Barbados by cattle egrets (Bubulcus ibis) 1956-1990. Source Colonial Waterbirds. 17(1). 1994. 86-90.

Lovich, J. 1996. Wildlife as Weeds. California Exotic Pest Plant Council 1996 Symposium Proceedings: U.S. Geological Survey.

Marion, L., D. Brugiere, and P. Grisser. 1993. An invasion of nesting Cattle Egrets Bubulcus ibis in France in 1992. Alauda. 61(3). 1993. 129-136.

Orgeira, J. L. 1996. Cattle egrets Bubulcus ibis at sea in the South Atlantic Ocean. Marine Ornithology 24: 57-58. Short communications 1996 57 (1996).

Scebba, S., G. Moschetti, M. Rocco, and R. Lenza. 1993. Observations of cattle egret, Bubulcus ibis, in Campania (S. Italy). Rivista Italiana di Ornitologia. 63(1). 1993. 124-125.

Smith, F. B. 1960. First Records of Cattle Egrets (Bubulcus ibis) in Guatemala.. Auk 77: pg 218 (General Notes).

Stone, C. P., and S. J. Anderson. 1988. Introduced Animals in Hawaii's Natural Areas. Vertebrate Pest Conference Proceedings collection: Proceedings of the Thirteenth Vertebrate Pest Conference. University of Nebraska.

Sueur, F. 1993. First case of the cattle egret Bubulcus ibis nesting at Marquenterre (Somme, north-west France). Alauda. 61(3). 1993. 195-197.

Varnham, K. 2006. Non-native species in UK Overseas Territories: a review. JNCC Report 372. Peterborough: United Kingdom.


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ISSG, 2011. Global Invasive Species Database (GISD). Invasive Species Specialist Group of the IUCN Species Survival Commission.

Krauss U, 2012. 161 Invasive Alien Species present in Saint Lucia and their current status. Caribbean Alien Invasive Species Network (CIASNET), 12 pp.

Yésou P; Clergeau P, 2005. Sacred Ibis: a new invasive species in Europe. Birding World, 18:517-526.

Distribution References

CABI Data Mining, 2001. CAB Abstracts Data Mining.,

CABI, Undated. CABI Compendium: Status inferred from regional distribution. Wallingford, UK: CABI

CABI, Undated a. CABI Compendium: Status as determined by CABI editor. Wallingford, UK: CABI

Invasive Species Specialist Group (ISSG), 2011. Global Invasive Species Database (GISD). In: Global Invasive Species Database (GISD), Auckland, New Zealand: University of Auckland.

Krauss U, 2012. 161 Invasive Alien Species present in Saint Lucia and their current status. In: Caribbean Alien Invasive Species Network (CIASNET), 12 pp.

Seebens H, Blackburn T M, Dyer E E, Genovesi P, Hulme P E, Jeschke J M, Pagad S, Pyšek P, Winter M, Arianoutsou M, Bacher S, Blasius B, Brundu G, Capinha C, Celesti-Grapow L, Dawson W, Dullinger S, Fuentes N, Jäger H, Kartesz J, Kenis M, Kreft H, Kühn I, Lenzner B, Liebhold A, Mosena A (et al), 2017. No saturation in the accumulation of alien species worldwide. Nature Communications. 8 (2), 14435.


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Reviewed by: Expert review underway: Michel Gauthier-Clerc, Station Biologique de la Tour Du Valat France

Principal sources:Gulf States Marine Fisheries Commission (GSFMC), 2005 Bubulcus ibis (Linnaeus, 1758)
Cornell Lab of Ornithology, 2003 Cattle Egret

    Compiled by: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Saturday, September 27, 2008

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