Green heron

Last updated

Green heron
Temporal range: Pleistocene–present
O
S
D
C
P
T
J
K
Pg
N
Butorides virescens2.jpg
Green heron have iridescent green feathers on their wings
Call
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Ardeidae
Genus: Butorides
Species:
B. virescens
Binomial name
Butorides virescens
Butorides virescens.svg
Range of B. virescens
  Breeding range
  Year-round range
  Wintering range
Synonyms

Ardea virescensLinnaeus, 1758
See text.

The green heron (Butorides virescens) is a small heron of North and Central America. Butorides is from Middle English butor "bittern" and Ancient Greek -oides, "resembling", and virescens is Latin for "greenish". [2]

Contents

It was long considered conspecific with its sister species the striated heron (Butorides striata), and together they were called "green-backed heron". Birds of the nominate subspecies (no matter which taxonomic arrangement is preferred) are extremely rare vagrants to western Europe for example, a sighting in Pembrokeshire in 2018 was only the second recorded sighting in Wales; [3] individuals from the Pacific coast of North America may similarly stray as far as Hawaii. [4] [5] [6]

Description

The green heron is relatively small; adult body length is about 44 cm (17 in). The neck is often pulled in tight against the body. Adults have a glossy, greenish-black cap, a greenish back and wings that are grey-black grading into green or blue, a chestnut neck with a white line down the front, grey underparts and short yellow legs. The bill is dark with a long, sharp point. Female adults tend to be smaller than males, and have duller and lighter plumage, particularly in the breeding season. Juveniles are duller, with the head sides, neck and underparts streaked brown and white, tan-splotched back and wing coverts, and greenish-yellow legs and bill. Hatchlings are covered in down feathers, light grey above, and white on the belly. [4] [5] [6]

The green heron's call is a loud and sudden kyow; it also makes a series of more subdued kuk calls. During courtship, the male gives a raah-rahh call with wide-open bill, makes noisy wingbeats and whoom-whoom-whoom calls in flight, and sometimes calls roo-roo to the female before landing again. While sitting, an aaroo-aaroo courtship call is also given. [5] [6]

Measurements: [7]

Taxonomy

As noted above, this species was formerly included in B. striata, which at that time was erroneously known as B. striatus. The Early Pleistocene B. validipes, whose fossil remains were discovered in Florida, might have been the ancestor of the green heron as the living species seems to replace the extinct relative in the fossil record.

Subspecies distinction is uncertain at best. The color variation between populations is less pronounced than between birds of the same population. Migratory populations are longer-winged than those resident year-round, but this cannot be used to delimit subspecies as it is quite obviously a consequence of differing habits and can be expected to undergo convergent evolution in unrelated populations of this species that just share the same habits. Thus, thorough molecular phylogenetic studies would be required to resolve the question of subspecies delimitation.

The following subspecies are commonly listed, though the validity of most of them is seriously disputed: [4]

Breeds in the United States west of the Rocky Mountains, south to northern Baja California Peninsula, Mexico. Some resident, most migrate to western Mexico in winter.
Bahamas. Resident.
Southern Baja California Peninsula, Mexico. Resident.
Southernmost US through Central America to central Panama, Caribbean. Resident.
Breeds from southeastern Canada to central and southern US east of the Rocky Mountains. Winters from southernmost US to northern South America.

Much of the dispute hinges upon the distinctness of the Caribbean and Central American populations, the second taxon in this species to be described. To describe the two most extreme views, some authors assemble the bulk of the mainland population in the nominate subspecies but treat the parapatric populations as distinct subspecies, while others place all resident populations in maculata and all migratory ones in virescens.

Ecology

"Green heron" by John J. Audubon Brooklyn Museum - Green Heron - John J. Audubon.jpg
"Green heron" by John J. Audubon

The habitat and foraging area of the green heron includes riparian zones, wetlands, ponds, and lakes, as well as human-made canals and ditches. [9] Green herons do not exhibit a particular preference for diurnal or nocturnal foraging, often engaging in both. [9] Shore-living individuals adapt to the rhythm of the tides.[ citation needed ] They mainly eat small fish, frogs and aquatic arthropods, but may take any invertebrate or vertebrate prey they can catch, including such animals like leeches, earthworms, dragonflies, damselflies, waterbugs, grasshoppers, spiders, [10] crayfish, [11] prawns, [10] mice, other rodents, lizards, tadpoles and snakes. [11] Some of the many fish eaten are: minnows, sunfish, catfish, perch, eels and, in urban areas, goldfish. [11] Green herons are intolerant of other birds – including conspecifics – when feeding and are not seen to forage in groups. They typically stand still on shore or in shallow water or perch upon branches and await prey. They are able to hover briefly to catch prey. [4] [5] [6] Green herons have been observed using captured prey (e.g. mayflies) or other objects (bread, feathers) to "bait-fish" – using a lure on the water's surface to attract fish. [12] This bait-fishing behavior is common among herons. [12]

The northern population moves to its breeding ranges during March and April; near the northernmost limit of the green heron's range, breeding is well underway by the end of May. The migration to the winter quarters starts in September; by late October, the birds are absent from regions where they do not stay all year. At least the northward migration does not seem to be affected by global warming; birds appear in their breeding ranges at the same time they did 100 years ago. [4] [6] [13] [14]

Individuals of non-migratory populations abandon their territories after breeding season to roam about the region. They may or may not return to the previous year's breeding location, depending on whether they found better habitat during these wanderings. In these populations, the breeding season is determined by rainfall and consequent prey availability. [4] [5] [6]

Green herons are seasonally monogamous. The pairs form in the breeding range, after an intense courtship display by the males, who select the nesting sites and fly in front of the female noisily and with puffed-up head and neck plumage. They nest in forest and swamp patches, over water or in plants near water. Nests are a platform of sticks, often in shrubs or trees, sometimes on the ground. Locations in trees are preferred, with some nests built up to 20 m (66 ft) off the ground although heights of several meters are more common. Rarely, large numbers of these birds congregate in heronries for nesting. [4] [5] [6]

The clutch is usually 2–6 pale green eggs, [5] which are laid in 2-day intervals (though the second egg may be laid up to 6 days later than the first). [15] After the last egg has been laid, both parents incubate for about 19–21 days until hatching, and feed the young birds. [16] The frequency of feedings decreases as the offspring near fledging. The young sometimes start to leave the nest at 16 days of age, but are not fully fledged and able to fend for themselves until 30–35 days old. Sometimes – particularly in the tropical parts of its range – the green heron breeds twice a year. [4] [5] [6]

Tool use

Green herons are one of the few species of bird known to use tools. In particular, they commonly use bread crusts, insects, or other items as bait. The bait is dropped onto the surface of a body of water to lure fish. When a fish takes the bait, the green heron then grabs and eats the fish. [17]

Related Research Articles

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

The great blue heron is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North and Central America, as well as far northwestern South America, the Caribbean and the Galápagos Islands. It is occasionally found in the Azores and is a rare vagrant to Europe. An all-white population found in south Florida and the Florida Keys is known as the great white heron. Debate exists about whether this represents a white color morph of the great blue heron, a subspecies of it, or an entirely separate species.

<span class="mw-page-title-main">Black-necked grebe</span> Water bird from parts of Africa, Eurasia, and the Americas

The black-necked grebe or eared grebe is a member of the grebe family of water birds. It was described in 1831 by Christian Ludwig Brehm. There are currently three accepted subspecies, including the nominate subspecies. Its breeding plumage features distinctive ochre-coloured feathers which extend behind its eye and over its ear coverts. The rest of the upper parts, including the head, neck, and breast, are coloured black to blackish brown. The flanks are tawny rufous to maroon-chestnut, and the abdomen is white. In its non-breeding plumage, this bird has greyish-black upper parts, including the top of the head and a vertical stripe on the back of the neck. The flanks are also greyish-black. The rest of the body is a white or whitish colour. The juvenile has more brown in its darker areas. The subspecies californicus can be distinguished from the nominate by the former's usually longer bill. The other subspecies, P. n. gurneyi, can be differentiated by its greyer head and upper parts and by its smaller size. P. n. gurneyi can also be told apart by its lack of a non-breeding plumage. This species is present in parts of Africa, Eurasia, and the Americas.

<span class="mw-page-title-main">American white ibis</span> Bird in the ibis family

The American white ibis is a species of bird in the ibis family, Threskiornithidae. It is found from Virginia via the Gulf Coast of the United States south through most of the coastal New World tropics. This particular ibis is a medium-sized bird with an overall white plumage, bright red-orange down-curved bill and long legs, and black wing tips that are usually only visible in flight. Males are larger and have longer bills than females. The breeding range runs along the Gulf and Atlantic Coast, and the coasts of Mexico and Central America. Outside the breeding period, the range extends further inland in North America and also includes the Caribbean. It is also found along the northwestern South American coastline in Colombia and Venezuela. Populations in central Venezuela overlap and interbreed with the scarlet ibis. The two have been classified by some authorities as a single species.

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

The white-faced ibis is a wading bird in the ibis family, Threskiornithidae.

<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">Grey heron</span> Long-legged predatory wading bird

The grey heron is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia, and also parts of Africa. It is resident in much of its range, but some populations from the more northern parts migrate southwards in autumn. A bird of wetland areas, it can be seen around lakes, rivers, ponds, marshes and on the sea coast. It feeds mostly on aquatic creatures which it catches after standing stationary beside or in the water, or stalking its prey through the shallows.

<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 is also 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">Ruddy turnstone</span> Species of bird

The ruddy turnstone is a small cosmopolitan wading bird, one of two species of turnstone in the genus Arenaria.

<span class="mw-page-title-main">Common goldeneye</span> Species of bird

The common goldeneye or simply goldeneye is a medium-sized sea duck of the genus Bucephala, the goldeneyes. Its closest relative is the similar Barrow's goldeneye. The genus name is derived from the Ancient Greek boukephalos, a reference to the bulbous head shape of the bufflehead. The species name is derived from the Latin clangere.

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

The yellow-crowned night heron, is one of two species of night heron in genus Nyctanassa. Unlike the black-crowned night heron, which has a worldwide distribution, the yellow-crowned is restricted to the Americas. It is known as the bihoreau violacé in French and the pedrete corona clara or yaboa común in some Spanish-speaking countries.

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

The black-crowned night-heron, or black-capped night-heron, commonly shortened to just night-heron in Eurasia, is a medium-sized heron found throughout a large part of the world, including parts of Europe, Asia, and North and South America. In Australasia it is replaced by the closely related nankeen night-heron, with which it has hybridized in the area of contact.

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

The snowy egret 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.

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

The striated heron also known as mangrove heron, little green heron or green-backed heron, is a small heron, about 44 cm tall. Striated herons are mostly sedentary and noted for some interesting behavioral traits. Their breeding habitat is small wetlands in the Old World tropics from west Africa to Japan and Australia, and in South America and the Caribbean. Vagrants have been recorded on Oceanic islands, such as Chuuk and Yap in the Federated States of Micronesia, the Marianas and Palau; the bird recorded on Yap on February 25, 1991, was from a continental Asian rather than from a Melanesian population, while the origin of the bird seen on Palau on May 3, 2005 was not clear.

<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">Tricolored heron</span> Species of bird

The tricolored heron, formerly known as the Louisiana heron, is a small species of heron native to coastal parts of the Americas. The species is more solitary than other species of heron in the Americas and eats a diet consisting mostly of small fish.

<span class="mw-page-title-main">Roseate spoonbill</span> Species of bird

The roseate spoonbill is a gregarious wading bird of the ibis and spoonbill family, Threskiornithidae. It is a resident breeder in both South and North America. The roseate spoonbill's pink color is diet-derived, consisting of the carotenoid pigment canthaxanthin, like the American flamingo.

<span class="mw-page-title-main">Green-backed heron</span> Index of animals with the same common name

"Green-backed heron" is a collective term for certain herons. Small and compact among herons, these birds often feature green plumage – rare among the Ardeidae –, in particular on the back, wings and scapulars.

<i>Butorides</i> Genus of birds

Butorides is a genus of small herons. It contains three similar species, the green heron or green-backed heron, Butorides virescens, the lava heron, and the striated heron, Butorides striatus. A fossil species, Butorides validipes, is known from the Early Pleistocene of Florida in the United States. Butorides is from Middle English Butor "bittern" and Ancient Greek -oides, "resembling".

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

The white-throated swift is a swift of the family Apodidae native to western North America, south to cordilleran western Honduras. Its coastal range extends as far north as Northern California, while inland it has migratory populations found throughout the Great Basin and Rocky Mountain regions, ranging as far north as southern British Columbia. White-throated swifts are found in open areas near cliffs, rock faces, or man-made structures, where they roost. Swifts are social birds, and groups are often seen roosting and foraging for flying insects together.

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

The cocoi heron is a species of long-legged wading bird in the heron family Ardeidae found across South America. It has predominantly pale grey plumage with a darker grey crest. A carnivore, it hunts fish and crustaceans in shallow water.

References

  1. BirdLife International (2012). "Butorides virescens". IUCN Red List of Threatened Species . 2012. Retrieved 26 November 2013.
  2. Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp.  81, 402. ISBN   978-1-4081-2501-4.
  3. "Rare green heron spotted in Llanmill, Pembrokeshire". BBC News. 30 April 2018. Retrieved 30 April 2018.
  4. 1 2 3 4 5 6 7 8 Jutglar, Francesc (1992): 33. Green-backed Heron. In: del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (eds.): Handbook of Birds of the World (Volume 1: Ostrich to Ducks): 417, plate 28. Lynx Edicions, Barcelona. ISBN   84-87334-10-5
  5. 1 2 3 4 5 6 7 8 Cornell Lab of Ornithology. "Green Heron" . Retrieved 2010-04-08.
  6. 1 2 3 4 5 6 7 8 Dewey, T. & Butzbaugh, J. (2001): Animal Diversity Web: Butorides virescens. Retrieved 2008-FEB-12.
  7. "Green Heron Identification, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 2020-09-26.
  8. "ITIS Report: Butorides virescens". Integrated Taxonomic Information System . Retrieved 28 August 2014.
  9. 1 2 Moore, Amanda A.; Green, M. Clay; Huffman, David G.; Simpson, Thomas R. (2016). "Green Herons (Butorides virescens) in an Urbanized Landscape: Does Recreational Disturbance Affect Foraging Behavior?". The American Midland Naturalist. 176 (2): 222–233.
  10. 1 2 "Butorides virescens (Green Heron)" (PDF). The Online Guide to the Animals of Trinidad and Tobago. University of the West Indies.
  11. 1 2 3 "Butorides virescens (Green heron)". Animal Diversity Web .
  12. 1 2 Davis Jr., William E.; Zickefoose, Julie (1998). "Bait-fishing by Birds: A Fascinating Example of Tool Use". Bird Observer. 26 (3): 139–143.
  13. Henninger, W.F. (1906). "A preliminary list of the birds of Seneca County, Ohio" (PDF). Wilson Bulletin . 18 (2): 47–60.
  14. Ohio Ornithological Society (2004): Annotated Ohio state checklist Archived 2004-07-18 at the Wayback Machine .
  15. Cornell Lab of Ornithology. "Green Heron" . Retrieved 2011-05-11.
  16. Seattle Audubon Society. "Green Heron". Archived from the original on 2016-03-04. Retrieved 2010-04-08.
  17. "Green Heron Overview, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 2022-05-22.