Pacific reef heron

Last updated

Pacific reef heron
Egretta sacra.jpg
Dark morph
Eastern Reef Egret.jpg
Light morph
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Ardeidae
Genus: Egretta
Species:
E. sacra
Binomial name
Egretta sacra
(Gmelin, 1789)

The Pacific reef heron (Egretta sacra), also known as the eastern reef heron or eastern reef egret, is a species of heron found throughout southern Asia and Oceania. It occurs in two colour morphs with either slaty grey or pure white plumage. The sexes are similar in appearance.

Contents

Taxonomy

The Pacific reef heron was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae . He placed it with the herons, cranes and egrets in the genus Ardea and coined the binomial name Ardea sacra. [2] Gmelin based his description on the "Sacred heron" that had been described in 1785 by the English ornithologist John Latham in his multi-volume work A General Synopsis of Birds. The naturalist Joseph Banks had provided Latham with a specimen of a white morph that had been collected on Tahiti. [3] [4] The Pacific reef heron is now placed with 12 other species in the genus Egretta that was introduced in 1817 by the German naturalist Johann Reinhold Forster. [5] [6] The genus name comes from the Provençal French for the little egret, aigrette, a diminutive of aigron, "heron". The specific epithet sacra is from Latin sacer meaning "sacred". [7] The Pacific reef heron is referred to by a variety of names by the indigenous peoples of the Pacific region. In New Zealand, multiple names have been given, including kākatai, matuku moana and matuku tai. [8] It is known as belō in Fiji, matu'u in the Samoan Islands, and motuku in Niue, Tonga, and Wallis Island. [9]

Two subspecies are recognised: [6]

Description

Pacific reef herons are medium-sized herons, reaching 57 to 66 cm (22 to 26 in) in length. They have a wingspan of between 90 and 110 cm (35 and 43 in) and reach an average weight of 400 g (14 oz). The species displays an unusual, non-sexual dimorphism, with some members having entirely white plumage ('light' morph) and others (the larger portion) being charcoal-grey ('dark' morph). The reason for the colour variation or "morph", is unknown, though it is most commonly thought to be related to camouflage. The plumage of immature herons tends to be browner and duller in colour. [10]

Pacific reef herons have yellow-grey legs, and the grey variety's throats and chins are marked by a narrow, white stripe. They have brown beaks, gold-yellow coloured eyes and the surrounding areas of their faces are normally of a greenish to yellow cast. [10] [11]

Distribution and habitat

The Pacific reef heron is widely distributed across southern Asia and Oceania. In Australia, Pacific reef herons inhabits most of the coastline, and offshore islands including the Torres Strait Islands. [12]

Pacific reef herons are widespread across Micronesia, with breeding records in Guam, the Marshall Islands, Northern Mariana Islands, and Palau, among various other islands. [13] The species also breeds throughout western Polynesia, including in Fiji, [9] French Polynesia, [14] and Tonga [15] – though it does not breed in Niue. [9] Surveys of the Fijian island of Rotuma, conducted in 1991 and 2018, suggest that the Pacific reef heron has recently colonized the island. [16]

New Zealand is considered to be the southern limit of the Pacific reef heron's distribution. [17] Despite being relatively uncommon, the herons are found throughout the country, though are most common in Northland. [18]

Behaviour and ecology

Breeding

The species lay clutches of eggs year-round in colonies in the jungle, between palms and mangroves or in cavities of old buildings. Two to three paled greenish-blue eggs are laid in nests constructed from branches and blossoms. Males and females share brooding tasks. They normally have a 28-day brood period. After chicks are hatched, parents provide approximately five weeks of support. [19]

Food and feeding

Their food sources are made up predominantly of varieties of ocean-based fish, crustaceans, molluscs and worms. [19] This heron hunts during both day and night, depending on the rise and fall of the tides. During the day, it hunts in shallow waters; standing motionless with wings open like an umbrella to reduce reflections and create shade which attracts fish. [20]

Conservation status

In New Zealand, the Pacific reef heron has the conservation status of "Nationally endangered". It has been classified as "Regionally Critical" in the Wellington region. [21]

Related Research Articles

<span class="mw-page-title-main">Egret</span> Type of bird of the heron family

Egrets are herons, generally long-legged wading birds, that have white or buff plumage, developing fine plumes during the breeding season. Egrets are not a biologically distinct group from herons and have the same build.

<span class="mw-page-title-main">Heron</span> Family of birds

Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 72 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genera Botaurus and Ixobrychus are referred to as bitterns, and, together with the zigzag heron, or zigzag bittern, in the monotypic genus Zebrilus, form a monophyletic group within the Ardeidae. Egrets do not form a biologically distinct group from herons, and tend to be named differently because they are mainly white or have decorative plumes in breeding plumage. Herons, by evolutionary adaptation, have long beaks.

<span class="mw-page-title-main">Great egret</span> Species of bird

The great egret (Ardea alba), also known as the common egret, large egret, or great white egret or great white heron, is a large, widely distributed egret. The four subspecies are found in Asia, Africa, the Americas, and southern Europe. Recently, it has also been spreading to more northern areas of Europe. Distributed across most of the tropical and warmer temperate regions of the world, it builds tree nests in colonies close to water.

<span class="mw-page-title-main">Little egret</span> Species of water bird

The little egret is a species of small heron in the family Ardeidae. It is a white bird with a slender black beak, long black legs and, in the western race, yellow feet. As an aquatic bird, it feeds in shallow water and on land, consuming a variety of small creatures. It breeds colonially, often with other species of water birds, making a platform nest of sticks in a tree, bush or reed bed. A clutch of three to five bluish-green eggs is laid and incubated by both parents for about three weeks. The young fledge at about six weeks of age.

<span class="mw-page-title-main">Cattle egret</span> Cosmopolitan genus of heron

The cattle egret (Bubulcus) is a cosmopolitan genus of heron found in the tropics, subtropics, and warm-temperate zones. According to the IOC bird list, it contains two species, the western cattle egret and the eastern cattle egret, although some authorities regard them as a single species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa, and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.

<span class="mw-page-title-main">Western reef heron</span> Species of bird

The western reef heron, also called the western reef egret, is a medium-sized heron found in southern Europe, Africa and parts of Asia. It has a mainly coastal distribution and occurs in several plumage forms: a slaty-grey plumage in which it can only be confused with the rather uncommon dark morph of the Little egret ; a white form which can look very similar to the little egret although the bill tends to be paler and larger and the black form with white throat E. g. gularis of West Africa. There are also differences in size, structure and foraging behaviour. There have been suggestions that the species hybridizes with the Little Egret, and based on this, some authors treat schistacea and gularis as subspecies of Egretta garzetta. Works that consider the Western Reef Heron as a valid species include the nominate gularis and schistacea as subspecies.

<span class="mw-page-title-main">White-faced heron</span> Species of bird

The white-faced heron also known as the white-fronted heron, and incorrectly as the grey heron, or blue crane, is a common bird throughout most of Australasia, including New Guinea, the islands of Torres Strait, Indonesia, New Zealand, and all but the driest areas of Australia.

<span class="mw-page-title-main">Cinnamon bittern</span> Species of bird

The cinnamon bittern or chestnut bittern is a small Old World bittern, breeding in tropical and subtropical Asia from India east to China and Indonesia. It is mainly resident, but some northern birds migrate short distances. This species was formerly placed in the genus Ixobrychus.

<span class="mw-page-title-main">Reddish egret</span> Species of bird

The reddish egret is a medium-sized heron that is a resident breeder in Central America, the Bahamas, the Caribbean, the Gulf Coast of the United States, and Mexico. The egret is known for its unusual foraging behavior compared to other herons as well as its association with mud flats, its habitat of choice.

<span class="mw-page-title-main">Pacific black duck</span> Species of bird

The Pacific black duck is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east. It is usually called the grey duck in New Zealand, where it is also known by its Maori name, pārera.

<span class="mw-page-title-main">Nankeen night heron</span> Species of bird

The nankeen night heron is a heron that belongs to the genus Nycticorax and the family Ardeidae. Due to its distinctive reddish-brown colour, it is also commonly referred to as the rufous night heron. It is primarily nocturnal and is observed in a broad range of habitats, including forests, meadows, shores, reefs, marshes, grasslands, and swamps. The species is 55 to 65 cm in length, with rich cinnamon upperparts and white underparts. The nankeen night heron has a stable population size, and is classified as a species of least concern by the International Union for Conservation of Nature (IUCN).

<i>Ardea</i> (bird) Genus of birds

Ardea is a genus of herons. These herons are generally large in size, typically 80–100 cm or more in length.

<i>Egretta</i> Genus of birds

Egretta is a genus of medium-sized herons, mostly breeding in warmer climates.

<span class="mw-page-title-main">Zigzag heron</span> Species of bird

The zigzag heron is a species of heron in the family Ardeidae, also including egrets and bitterns. It is in the monotypic genus Zebrilus. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela. Its natural habitat is subtropical or tropical swamps.

<span class="mw-page-title-main">Spotless crake</span> Species of bird

The spotless crake is a species of bird in the rail family, Rallidae. It is widely distributed species occurring from the Philippines, New Guinea, Australia, New Zealand across the southern Pacific Ocean to the Marquesas Islands to the south east along the Tuamotus island chain to Pitcairn Oeno island,

<span class="mw-page-title-main">Western cattle egret</span> Species of bird

The western cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Most taxonomic authorities lump this species and the eastern cattle egret together, but some separate them. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.

References

  1. ↑ BirdLife International (2018). "Egretta sacra". IUCN Red List of Threatened Species . 2018: e.T22696980A131759460. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22696980A131759460.en . Retrieved 12 November 2021.
  2. ↑ Gmelin, Johann Friedrich (1789). Systema naturae per regna tria naturae : secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1, Part 2 (13th ed.). Lipsiae [Leipzig]: Georg. Emanuel. Beer. pp. 640–641.
  3. ↑ Latham, John (1785). A General Synopsis of Birds. Vol. 3, Part 1. London: Printed for Leigh and Sotheby. pp. 92–93, No. 62.
  4. ↑ Mayr, Ernst; Cottrell, G. William, eds. (1979). Check-List of Birds of the World. Vol. 1 (2nd ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 215.
  5. ↑ Forster, T. (1817). A Synoptical Catalogue of British Birds; intended to identify the species mentioned by different names in several catalogues already extant. Forming a book of reference to Observations on British ornithology. London: Nichols, son, and Bentley. p. 59.
  6. 1 2 Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (August 2022). "Ibis, spoonbills, herons, Hamerkop, Shoebill, pelicans". IOC World Bird List Version 12.2. International Ornithologists' Union. Retrieved 28 November 2022.
  7. ↑ Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp.  143, 345. ISBN   978-1-4081-2501-4.
  8. ↑ Ryan, P. M. (2012). The Raupo Dictionary of Modern Māori. Raupō. ISBN   9780143567899.
  9. 1 2 3 Watling, Dick (2001). A guide to the birds of Fiji & Western Polynesia. Suva, Fiji: Environmental Consultants Fiji. p. 99.
  10. 1 2 Edgar, A. T. (1978). "The reef heron (Egretta sacra) in New Zealand" (PDF). Notornis. 25 (1): 25–58.
  11. ↑ Marchant, S.; Higgins, P.G., eds. (1990). "Ardea sacra Eastern Reef Egret" (PDF). Handbook of Australian, New Zealand & Antarctic Birds. Volume 1: Ratites to ducks; Part B, Australian pelican to ducks. Melbourne, Victoria: Oxford University Press. pp. 1002–1009, Plate 71. ISBN   978-0-19-553068-1.
  12. ↑ Lavery, Tyrone H.; Watson, Justin J.; Leung, Luke K.-P. (2012). "Terrestrial vertebrate richness of the inhabited Torres Strait Islands, Australia". Australian Journal of Zoology. 60 (3): 180–191. doi:10.1071/ZO12043. S2CID   73537024.
  13. ↑ Wiles, Gary J. (2005). "A checklist of the birds and mammals of Micronesia". Micronesia. 38 (1): 149–189.
  14. ↑ Beaune, David; Ghestemme, Thomas; Raust, Philippe; Blanvillain, Caroline (2018). "Herons of French Polynesia: threats, status and conservation" (PDF). Journal of Heron Biology and Conservation. 3. Retrieved 30 January 2020.
  15. ↑ Steadman, David W. (1993). "Biogeography of Tongan birds before and after human impact". Proceedings of the National Academy of Sciences of the United States of America. 90 (3): 818–882. Bibcode:1993PNAS...90..818S. doi: 10.1073/pnas.90.3.818 . PMC   45761 . PMID   11607357.
  16. ↑ Cibois, Alice; Thibault, Jean-Claude; Watling, Dick (2019). "Birds and bats of Rotuma, Fiji" (PDF). Notornis. 66 (3): 139–149.
  17. ↑ Bell, Mike (2010). "A census of reef herons (Ardea sacra) in the Marlborough Sounds" (PDF). Notornis. 57 (3): 152–155.
  18. ↑ Chambers, Stuart (2009). Birds of New Zealand: locality guide (PDF) (3rd ed.). Orewa, New Zealand: Arun Books. p. 91.
  19. 1 2 "Reef heron Egretta sacra". New Zealand Birds Online. Retrieved 29 May 2021.
  20. ↑ "Pacific or Eastern Reef Egret". www.oiseaux-birds.com. Retrieved 25 September 2024.
  21. ↑ McArthur, Nikki; Ray, Samantha; Crowe, Patrick; Bell, Mike (August 2019). A baseline survey of the indigenous bird values of the Wellington region coastline (PDF) (Report). p. 19.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.