Egretta thula

Egretta thula, Photo : David Hall, Fish and Wildlife Service

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Cladus: Sarcopterygii
Cladus: Rhipidistia
Cladus: Tetrapodomorpha
Cladus: Eotetrapodiformes
Cladus: Elpistostegalia
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Infraclassis: Archosauromorpha
Cladus: Crurotarsi
Divisio: Archosauria
Cladus: Avemetatarsalia
Cladus: Ornithodira
Subtaxon: Dinosauromorpha
Cladus: Dinosauriformes
Cladus: Dracohors
Cladus: Dinosauria
Ordo: Saurischia
Cladus: Eusaurischia
Subordo: Theropoda
Cladus: Neotheropoda
Cladus: Averostra
Cladus: Tetanurae
Cladus: Avetheropoda
Cladus: Coelurosauria
Cladus: Tyrannoraptora
Cladus: Maniraptoromorpha
Cladus: Maniraptoriformes
Cladus: Maniraptora
Cladus: Pennaraptora
Cladus: Paraves
Cladus: Eumaniraptora
Cladus: Avialae
Infraclassis: Aves
Cladus: Euavialae
Cladus: Avebrevicauda
Cladus: Pygostylia
Cladus: Ornithothoraces
Cladus: Ornithuromorpha
Cladus: Carinatae
Parvclassis: Neornithes
Cohors: Neognathae
Cladus: Neoaves
Cladus: Aequornithes
Ordo: Pelecaniformes

Familia: Ardeidae
Subfamilia: Ardeinae
Genus: Egretta
Species: E. thula
Subspecies: E. t. brewsteri – E. t. thula
Name

Egretta thula (Molina, 1782)

original combination: Ardea thula

References

Molina, J.I. 1782. Saggio sulla Storia Naturale del Chili. Stamperia di S. Tomaso d'Aquino: Bologna. 367 pp. Reference page. Original description p. 235 p.344

Vernacular names
العربية: مالك الحزين
беларуская: Белая амерыканская чапля
čeština: volavka bělostná
dansk: Snehejre
Deutsch: Schmuckreiher
English: Snowy Egret
Esperanto: Neĝa egretardeo
español: Garceta Nívea, Garcita Blanca
suomi: lumihaikara
français: Aigrette neigeuse
magyar: Hókócsag
íslenska: Ljómahegri
italiano: Garzetta nivea
日本語: ユキコサギ, yukikosagi
lietuvių: Snieginis garnys
Nederlands: Amerikaanse kleine zilverreiger
norsk: Snøhegre
polski: Czapla śnieżna
português do Brasil: Garça-branca-pequena
português: Garça-branca-pequena, Garcinha-branca
Runa Simi: Yuraq waqar
русский: Белая американская цапля
slovenčina: volavka žltoprstá
српски / srpski: Снежна чапља / Snežna čaplja
svenska: Snöhäger
中文: 雪鹭

The snowy egret (Egretta thula) is a small white heron. The genus name comes from Provençal French for the little egret, aigrette, which is a diminutive of aigron, 'heron'. The species name thula is the Araucano term for the black-necked swan, applied to this species in error by Chilean naturalist Juan Ignacio Molina in 1782.[3]

The snowy egret is the American counterpart to the very similar Old World little egret, which has become established in the Bahamas. At one time, the plumes of the snowy egret were in great demand as decorations for women's hats.[4] They were hunted for these plumes and this reduced the population of the species to dangerously low levels.[5] Now protected in the United States by law, under the Migratory Bird Treaty Act, this bird's population has rebounded.

Description

Adult snowy egrets are entirely white apart from the yellow lores between the long black bill and the eye, black legs, and bright yellow feet. The nape and neck bear long, shaggy plumes known as aigrettes.[6] Immature snowy egrets have duller, greenish legs.

Measurements:[7]

Length: 22.1–26.0 in (56–66 cm)
Weight: 13.1 oz (370 g)
Wingspan: 39.4 inches (100 cm)

Distribution and habitat

The snowy egret is native to North, Central and South America. It is present all year round in South America, ranging as far south as Chile and Argentina. It also occurs throughout the year in the West Indies, Florida and coastal regions of North and Central America. Elsewhere, in the southern part of the United States, it is migratory, breeding in California, Nevada, Utah, Colorado, Arizona, New Mexico, Texas, Louisiana and Mississippi. It is found in wetlands of many types; marshes, riverbanks, lakesides, pools, salt marshes and estuaries. It is not found at high altitudes nor generally on the coast.[6] The snowy egret has occurred as a vagrant in Europe, in Iceland, Scotland and the Azores.[8] It has also been recorded in South Africa.[9]
Diet

The birds eat fish, crustaceans, insects, small reptiles, snails, frogs, toads,[10] worms (especially annelids)[11] and crayfish. They stalk prey in shallow water, often running or shuffling their feet, flushing prey into view by swaying their heads, flicking their wings or vibrating their bills. They may also hover, or "dip-fish" by flying with their feet just above the water surface. Snowy egrets may also stand still and wait to ambush prey, or hunt for insects stirred up by domestic animals in open fields. They sometimes forage in mixed species groups.[5]
Breeding

Snowy egrets breed in mixed colonies, which may include great egrets, night herons, tricolored herons, little blue herons, cattle egrets, glossy ibises and roseate spoonbills. The male establishes a territory and starts building the nest in a tree, vines or thick undergrowth. He then attracts a mate with an elaborate courtship display which includes dipping up and down, bill raising, aerial displays, diving, tumbling and calling. The immediate vicinity of the nest is defended from other birds and the female finishes the construction of the nest with materials brought by the male. It is constructed from twigs, rushes, sedges, grasses, Spanish moss and similar materials and may be 15 in (38 cm) across. Up to six pale bluish-green eggs are laid which hatch after about 24 days. The young are altricial and covered with white down when first hatched. They leave the nest after about 22 days.[5]
Fossil finds

Fossils of the snowy egret have been reported from the Talara tar seeps of Peru and in Bradenton in Manatee County and Haile XIB in Alachua County in Florida, United States.[2] The deposits were dated to the Late Pleistocene.[12][13][14][15]
Status

In the early twentieth century, the snowy egret was hunted extensively for their long breeding plumes that fashionable ladies wore on their hats. This trade was ended in 1910 in North America but continued for some time in Central and South America. Since then populations have recovered.[5] The bird has a very wide range and the total population is large. No particular threats have been recognised and the population trend seems to be upwards, so the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".[1]

References

BirdLife International (2016). "Egretta thula". IUCN Red List of Threatened Species. 2016: e.T22696974A93595536. doi:10.2305/IUCN.UK.2016-3.RLTS.T22696974A93595536.en. Retrieved 19 November 2021.
Egretta thula at Fossilworks.org
Jobling, 2010, p.143, 385
Saikku, Mikko (Autumn 1990). "The Extinction of the Carolina Parakeet". Environmental History Review. 14 (3): 9–10. doi:10.2307/3984724. JSTOR 3984724. S2CID 155475716.
"Snowy Egret: Life History". All About Birds. TheCornellLab. Retrieved 29 March 2019.
T. S. Schulenberg (2020). "Snowy Egret (Egretta thula)". In Poole, Alan F; Gill, Frank B (eds.). Snowy egret (Egretta thula). Cornell Lab of Ornithology: Neotropical Birds Online. doi:10.2173/bow.snoegr.01. S2CID 216257447. Retrieved 28 November 2019.
"Snowy Egret Identification, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 2020-09-26.
"Twitchers flock to see UK's first snowy egret". The Scotsman. Retrieved 25 December 2018.
Melanie Gosling (12 June 2015). "Rare bird draws watchers to Cape Town". Independent Online (originally in the Cape Times). Retrieved 31 August 2021.
"Egretta thula (Snowy egret)".
"Egretta thula (Snowy egret)".
Talara tar seeps at Fossilworks.org
Bradenton at Fossilworks.org
Haile XIB at Fossilworks.org

Ligon, 1966

Bibliography

Jobling, James A. 2010. The Helm Dictionary of Scientific Bird Names, 143, 385. Christopher Helm. Accessed 11 Dec 2019. ISBN 978-1-4081-2501-4
Ligon, J.D. 1965. A Pleistocene avifauna from Haile, Florida. Bulletin of the Florida State Museum, Biological Sciences 10. 127-158. Accessed 11 Dec 2019.