Family ARDEIDAE Leach, 1820

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Introduction

The Ardeidae are medium to large-sized birds, assigned to two readily recognised divisions: the herons (including egrets — their names having been selectively chosen because of colouration and plumage characters) and the bitterns. They have a cosmopolitan distribution, occurring on all continents apart from Antarctica. Amongst the larger species, herons are typically diurnal with some tendency towards a crepuscular lifestyle; their typical calls are a series of guttural croaks whereas the furtive bitterns are principally crepuscular, their calls including deep booming notes. Worldwide, there are 64 species, 12 of which, in nine genera, occur within Australian territory. All are long-necked and long-legged wading birds; the neck is articulated. The legs are long, possessing thin anisodactyl toes. Ardeid bodies are slim with long, broad wings and short tails. They all differ substantially from other groups with similar shapes (Ciconiidae, Threskiornithidae, Gruidae) by having retractable necks and slow flight; in flight the legs trail behind the body. They also have powder down on the breast, thighs and rump (bitterns lack powder down on the thighs). Possession of a comb-like structure on the third toe assists with plumage grooming. Bitterns also have an ability to erect their elongate neck feathers to be used either in display or threat.

Articulation (kinking) of the sixth neck vertebra enables it to be used as a fulcrum for the dagger-like bill when hunting prey. It also allows them to reposition their gullet either before or behind the vertebrae, thereby assisting in swallowing larger prey. There is a tendency for the neck to be longer in the diurnal herons and shorter in the bitterns. Their soft plumage, usually grey, black, brown or white, exhibits some variants, for example in breeding plumage the normally white Cattle Egret assumes a golden head and neck; and there is some dimorphism between white and grey in the Reef Egret. When breeding, many of the species with white plumage develop filamentous plumes which they use for displays. Typically the bill, as evidenced in Australian species, is long and fine; in some species the bill broadens and becomes shorter (night-herons). Bills are generally coloured yellow or brownish, becoming brighter and more colourful when the birds are breeding.

Ardeids inhabit freshwater wetlands; herons also inhabit open grasslands, including some park land in urban areas, and rocky and sandy coastal foreshores. Bitterns are inclined to frequent reedbeds in wetlands rather than grasslands and pastures. Both subgroups hunt by stalking their prey in shallow marine or fresh water. Often they will remain almost motionless until their prey appears. Their prey consists of fish and other marine life but will include young birds and small mammals. Once captured the prey are battered on an available rock or log before being consumed. Undigested bone or other material are regurgitated as a pellet.

Breeding is mostly conducted within treetop colonies while a small number prefer a solitary nesting arrangement; bitterns mostly prefer reedbeds. Within colonies, breeding is synchronised. Heron nests are a platform or shallow dish of twigs and leaves built into the outer twigs of trees or in tree forks; in contrast bitterns construct their shallow dish of rushes either in reedbeds or using twigs in tree forks. Two to four pale blue-green or white oval to long-oval eggs form a clutch; the incubation period is approximately 26 days. Among herons both adults share the responsibility of nest duties and the young are fed through regurgitation.

Excluded Taxa

Vagrant Species

CAVS:8038
ARDEIDAE: Ardea cinerea jouyi Clark, 1907 [Eastern Grey Heron]

CAVS:0908
ARDEIDAE: Ardea cinerea Linnaeus, 1758 [Grey Heron; vagrant to Christmas Island & WA — Swan Coastal Plain (SWA) Busselton, WA on the 20th May 2002] — Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [20, 111, 112]; Tony Palliser Submission No 368: Grey Heron Ardea cinerea. Busselton, WA. 20th May 2002. Birds Australia Rarities Committee. http://www.tonypalliser.com/barc/summaries/SUMM368.htm (accessed 4 April 2012)

CAVS:8039
ARDEIDAE: Ardea purpurea (Linnaeus, 1766) [Purple Heron]

CAVS:9945
ARDEIDAE: Ardeola bacchus (Bonaparte, 1855) [Chinese Pond Heron; vagrant to Cocos (Keeling) Island] — Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [21, 111, 112]

CAVS:9946
ARDEIDAE: Ardeola speciosa Horsfield, 1821 [Javan Pond Heron] — Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [21, 111, 112]

CAVS:8041
ARDEIDAE: Ardeola speciosa speciosa Horsfield, 1821 [Eastern Javan Pond Heron]

CAVS:8040
ARDEIDAE: Butorides striata amurensis (von Schrenk, 1860) [East Asian Striated Heron]

CAVS:8042
ARDEIDAE: Egretta garzetta garzetta (Linnaeus, 1766) [Chinese Little Egret]

CAVS:8075
ARDEIDAE: Egretta gularis (Bosc, 1792) [Western Reef Egret; vagrant to Cocos (Keeling) Island] — Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [112]

CAVS:8076
ARDEIDAE: Egretta gularis schistacea (Hemprich & Ehrenberg, 1828) [Arabian Western Reef Egret]

CAVS:8052
ARDEIDAE: Gorsachius goisagi Temminck, 1836 [Japanese Night Heron]

CAVS:8051
ARDEIDAE: Gorsachius melanolophus melanolophus (Raffles, 1822) [Malayan Night-Heron]

CAVS:0797
ARDEIDAE: Gorsachius melanolophus (Raffles, 1822) [Malayan Night-Heron; vagrant to Christmas Island] — Christidis, L. & Boles, W.E. 1994. The Taxonomy and Species of Birds of Australia and its Territories. Monograph 2. Melbourne : Royal Australasian Ornithologists Union iv 112 pp.; Simpson, K. & Day, N. 2004. Birds of Australia. Camberwell, Victoria : Penguin Group (Australia) Edn 7, pp. 382. [336]; Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [21, 112]

CAVS:0842
ARDEIDAE: Ixobrychus cinnamomeus (Gmelin, 1789) [Cinnamon Bittern; vagrant to Christmas Island] — Simpson, K. & Day, N. 2004. Birds of Australia. Camberwell, Victoria : Penguin Group (Australia) Edn 7, pp. 382. [336]; Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [20, 108, 112]

CAVS:0754
ARDEIDAE: Ixobrychus eurhythmus (Swinhoe, 1873) [Schrenk's Bittern; vagrant to Christmas Island] — Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [20, 108, 112]

CAVS:8037
ARDEIDAE: Ixobrychus flavicollis flavicollis (Latham, 1790) [Asian Black Bittern]

CAVS:0907
ARDEIDAE: Ixobrychus sinensis (Gmelin, 1789) [Yellow Bittern; vagrant to WA — Coolgardie (COO) & Christmas Island] — Marchant, S. & Higgins, P. (coordinators) 1990. Handbook of Australian, New Zealand and Antarctic Birds. Melbourne : Oxford University Press Vol. 1(B) pp. 737-1400. [1047]; Christidis, L. & Boles, W.E. 1994. The Taxonomy and Species of Birds of Australia and its Territories. Monograph 2. Melbourne : Royal Australasian Ornithologists Union iv 112 pp.; Simpson, K. & Day, N. 2004. Birds of Australia. Camberwell, Victoria : Penguin Group (Australia) Edn 7, pp. 382. [288]; Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [108, 112]

CAVS:0796
ARDEIDAE: Nycticorax nycticorax (Linnaeus, 1758) [Black-crowned Night-Heron; vagrant to Cocos (Keeling) Islands & Ashmore Reef] — Christidis, L. & Boles, W.E. 1994. The Taxonomy and Species of Birds of Australia and its Territories. Monograph 2. Melbourne : Royal Australasian Ornithologists Union iv 112 pp.; Simpson, K. & Day, N. 2004. Birds of Australia. Camberwell, Victoria : Penguin Group (Australia) Edn 7, pp. 382. [336]; Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp. [21, 112]

CAVS:8706
ARDEIDAE: Nycticorax nycticorax nycticorax (Linnaeus, 1758) [Eastern Black-crowned Night-Heron]

General References

Christidis, L. & Boles, W.E. 2008. Systematics and Taxonomy of Australian Birds. Melbourne : CSIRO Publishing 288 pp.

Grant, C.H.B. & Mackworth-Praed, C.W. 1933. Untitled. Bulletin of the British Ornithologists' Club 54: 73-75 [75]

History of changes