بلشون

Herons
Temporal range: Early Oligocene–Holocene 32–0 Ma[1]
Ardeidae-01.jpg
التصنيف العلمي e
أصنوفة غير معروفة (أصلحها): الحياة
مملكة: الحيوانية
Phylum: حبليات
Class: طيور
تحت رتبة: Ardei
الفصيلة: البلشونيات
Leach, 1820
Type genus
Ardea
Linnaeus, 1758
Genera

18 extant, see text

Heron range.png
Global distribution of herons
Synonyms

Cochlearidae

البلشون Ardea هو جنس من البلشونيات herons. الاسم اللاتيني للجنس يأتي من الكلمة اللاتينية ardea "بلشون". وتلك البلشونيات هي عموماً كبيرة الحجم، يبلغ طولها في المعتاد 80–100 سم أو أكثر.

The great egret (Ardea alba, left) resembles the other Ardea in habitus, and the little egret (Egretta garzetta, right) only in color.

These large herons are associated with wetlands where they prey on fish, frogs, and other aquatic species.

Most members of this almost worldwide group breed colonially in trees, building large stick nests. Northern species such as great blue, grey, and purple herons may migrate south in winter, although the first two do so only from areas where the waters freeze.

These are powerful birds with large spear-like bills, long necks and long legs, which hunt by waiting motionless or stalking their prey in shallow water before seizing it with a sudden lunge. They have a slow steady flight, with the neck retracted as is characteristic of herons and bitterns; this distinguishes them from storks, cranes, flamingos, and spoonbills, which extend their necks.

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الوصف

A beige heron with yellow legs and bill stands hunched on a wire mesh above water, its neck folded tightly to its body and hidden among feathers.
Yellow bittern with its neck fully retracted.

The herons are medium- to large-sized birds with long legs and necks. They exhibit very little sexual dimorphism in size. The smallest species is usually considered the dwarf bittern, which measures 25–30 cm (10–12 in) in length, although all the species in the genus Ixobrychus are small and many broadly overlap in size. The largest species of heron is the goliath heron, which stands up to 152 cm (60 in) tall. All herons can retract their necks by folding them into a tight S-shape, due to the modified shape of the cervical vertebrae, of which they have 20 or 21; the neck is retracted during flight, unlike most other long-necked birds. The neck is longer in the day herons than the night herons and bitterns. The legs are long and strong, and in almost every species are unfeathered from the lower part of the tibia (the exception is the zigzag heron). In flight, the legs and feet are generally held in a horizontal position, pointing backwards. Toes are long and thin, with three pointing forwards and one backwards.[2]

two herons, one with white plumage and one with slate grey, on a rock in the surf of the ocean
The Pacific reef heron has two colour morphs, the light and the dark.

The bill is generally long and harpoon-like. It can vary from extremely narrow, as in the agami heron, to wider as in the grey heron. The most atypical heron bill is owned by the boat-billed heron, which has a broad, thick bill. Herons' bills and other bare parts of the body are usually yellow, black, or brown in colour, although this can vary during the breeding season. The wings are broad and long, exhibiting 10 or 11 primary feathers (the boat-billed heron has only nine), 15–20 secondaries, and 12 rectrices (10 in the bitterns). The feathers of the herons are soft and the plumage is usually blue, black, brown, grey, or white, and can often be strikingly complex. Amongst the day herons, little sexual dimorphism in plumage is seen (except in the pond-herons); however, for the night herons and smaller bitterns, plumage differences between the sexes are the rule. Many species also have different colour morphs.[2] In the Pacific reef heron, both dark and light colour morphs exist, and the percentage of each morph varies geographically; its white morphs only occur in areas with coral beaches.[3]


Distribution and habitat

Lava heron, grey with a long bill and red feet and with small fish in bill amongst grey rocks
Lava herons are endemic to the Galápagos Islands, where they feed on fish and crabs in the intertidal and mangrove areas.

The herons are a widespread family with a cosmopolitan distribution. They exist on all continents except Antarctica and are present in most habitats except the coldest extremes of the Arctic, extremely high mountains, and the driest deserts. Almost all species are associated with water; they are essentially non-swimming waterbirds that feed on the margins of lakes, rivers, swamps, ponds, and the sea. They are predominantly found in lowland areas, although some species live in alpine areas, and the majority of species occur in the tropics.[2]

The herons are a highly mobile family, with most species being at least partially migratory; for example, the grey heron is mostly sedentary in Britain, but mostly migratory in Scandinavia. Birds are particularly inclined to disperse widely after breeding, but before the annual migration, where the species is colonial, searching out new feeding areas and reducing the pressures on feeding grounds near the colony. The migration typically occurs at night, usually as individuals or in small groups.[2]


السلوك والبيئة

المأكل

A white heron with grey legs and a yellow/orange bill standing in green grasses throwing a lizard with its bill
A great egret manipulating its prey, a lizard, before swallowing

The herons and bitterns are carnivorous. The members of this family are mostly associated with wetlands and water and feed on a variety of live aquatic prey. Their diet includes a wide variety of aquatic animals, including fish, reptiles, amphibians, crustaceans, molluscs, and aquatic insects. Individual species may be generalists or specialize in certain prey types, such as the yellow-crowned night heron, which specializes in crustaceans, particularly crabs.[4] Many species also opportunistically take larger prey, including birds and bird eggs, rodents, and more rarely carrion. Even more rarely, herons eating acorns, peas, and grains have been reported, but most vegetable matter consumed is accidental.[2]

Four black herons standing in low water with vegetation holding their wings over their bodies forming what looks like umbrellas
Black herons holding wings out to form an umbrella-like canopy under which to hunt

The most common hunting technique is for the bird to sit motionless on the edge of or standing in shallow water and to wait until prey comes within range. Birds may either do this from an upright posture, giving them a wider field of view for seeing prey or from a crouched position, which is more cryptic and means the bill is closer to the prey when it is located. Having seen prey, the head is moved from side to side, so that the heron can calculate the position of the prey in the water and compensate for refraction, and then the bill is used to spear the prey.[2]

Tricoloured heron fishing, using wings to eliminate reflection from the water, which improves its ability to sight prey

In addition to sitting and waiting, herons may feed more actively. They may walk slowly, around or less than 60 paces a minute, snatching prey when it is observed. Other active feeding behaviours include foot stirring and probing, where the feet are used to flush out hidden prey.[5] The wings may be used to frighten prey (or possibly attract it to shade) or to reduce glare; the most extreme example of this is exhibited by the black heron, which forms a full canopy with its wings over its body.[6]

Some species of heron, such as the little egret and grey heron, have been documented using bait to lure prey to within striking distance. Herons may use items already in place, or actively add items to the water to attract fish such as the banded killifish. Items used may be man-made, such as bread;[7] alternatively, striated herons in the Amazon have been watched repeatedly dropping seeds, insects, flowers, and leaves into the water to catch fish.[8]

Three species, the black-headed heron, whistling heron, and especially the cattle egret, are less tied to watery environments and may feed far away from water. Cattle egrets improve their foraging success by following large grazing animals, catching insects flushed by their movement. One study found that the success rate of prey capture increased 3.6 times over solitary foraging.[9]

Breeding

A brown heron with brown, back and beige coloured streaks stands in similarly coloured dead grasses, its head pointed upwards
The larger bitterns, like this American bittern, are solitary breeders. To advertise for mates, males use loud, characteristic calls, referred to as booming.

While the family exhibits a range of breeding strategies, overall, the herons are monogamous and mostly colonial. Most day herons and night herons are colonial, or partly colonial depending on circumstances, whereas the bitterns and tiger herons are mostly solitary nesters. Colonies may contain several species, as well as other species of waterbirds. In a study of little egrets and cattle egrets in India, the majority of the colonies surveyed contained both species.[10] Nesting is seasonal in temperate species; in tropical species, it may be seasonal (often coinciding with the rainy season) or year-round. Even in year-round breeders, nesting intensity varies throughout the year. Tropical herons typically have only one breeding season per year, unlike some other tropical birds which may raise up to three broods a year.[2]

Courtship usually takes part on the nest. Males arrive first and begin the building of the nest, where they display to attract females. During courtship, the male employs a stretch display and uses erectile neck feathers; the neck area may swell. The female risks an aggressive attack if she approaches too soon and may have to wait up to four days.[11] In colonial species, displays involve visual cues, which can include adopting postures or ritual displays, whereas in solitary species, auditory cues, such as the deep booming of the bitterns, are important. The exception to this is the boat-billed heron, which pairs up away from the nesting site. Having paired, they continue to build the nest in almost all species, although in the little bittern and least bittern, only the male works on the nest.[2]

Some ornithologists have reported observing female herons attaching themselves to impotent mates, then seeking sexual gratification elsewhere.[2]

The nests of herons are usually found near or above water. Although the nests of a few species have been found on the ground where suitable trees or shrubs are unavailable, they are typically placed in vegetation.[2][10] Trees are used by many species, and here they may be placed high up from the ground, whereas species living in reed beds may nest very close to the ground.[2] Though the majority of nesting of herons is seen in or immediately around water, colonies commonly occur in several cities when human persecution is absent.[12]

Generally, herons lay between three and seven eggs. Larger clutches are reported in the smaller bitterns and more rarely some of the larger day herons, and single-egg clutches are reported for some of the tiger herons. Clutch size varies by latitude within species, with individuals in temperate climates laying more eggs than tropical ones. On the whole, the eggs are glossy blue or white, with the exception being the large bitterns, which lay olive-brown eggs.[2]

Taxonomy and systematics

Analyses of skeletons, mainly skulls, suggested that the Ardeidae could be split into a diurnal and a crepuscular/nocturnal group which included the bitterns. From DNA studies, and from skeletal analyses that focussed more on bones of the body and limbs, that two-group division has been revealed to be incorrect.[13] Rather, the similarities in skull morphology among certain herons reflect convergent evolution to cope with the different challenges of daytime and nighttime feeding. Today, it is believed that three major groups can be distinguished,[14][15] which are:

  • tiger herons and the boatbill
  • bitterns
  • day herons and egrets, and night herons

The night herons may still warrant separation from the day herons and egrets (as subfamily Nycticoracinae, as it was traditionally done). However, the position of some genera (e.g. Butorides or Syrigma) is unclear at the moment, and molecular studies have so far suffered from studying only a small number of taxa. Especially among the subfamily Ardeinae, the relationships are very inadequately resolved. The arrangement presented here should be considered provisional.

A 2008 study suggests that this family belongs to the Pelecaniformes.[16] In response to these findings, the International Ornithological Congress reclassified Ardeidae and their sister taxa Threskiornithidae under the order Pelecaniformes instead of the previous order of Ciconiiformes.[17]

The cladogram shown below is based on a molecular phylogenetic study of the Ardeidae by Jack Hruska and collaborators published in 2023.[18] For several species these results conflict with the taxonomy published online in July 2023 by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).[17] The least bittern (Ixobrychus exilis) and the stripe-backed bittern (Ixobrychus involucris) were nested with members of the genus Botaurus. Hruska and collaborators resurrected the genus Calherodius Peters, 1931 to contain two night herons (the white-backed night heron and the white-eared night heron) that were previously placed in Gorsachius. The western cattle egret (Bubulcus ibis) was embedded in the genus Ardea. The eastern cattle egret (Bubulcus coromandus) was not sampled. The placement of the forest bittern (Zonerodius heliosylus) was ambiguous, but the results suggest that it is probably closely related to members of the genus Ardeola rather than to the subfamily Tigriornithinae.[18]

Ardeidae

Tigriornithinae

Tigriornis – white-crested tiger heron

Tigrisoma – tiger herons (3 species)

Cochleariinae

Cochlearius – boat-billed heron

Agamiinae

Agamia – agami heron

Botaurinae

Zebrilus – zigzag heron

Botaurus – bitterns (6 species)

Ixobrychus – bitterns (8 species of which 1 extinct)

Ardeinae

Gorsachius – night herons (4 species)

Calherodius – night herons (2 species)

Pilherodius – capped heron

Syrigma – whistling heron

Egretta – herons and egrets (13 species)

Nyctanassa – night herons (2 species of which 1 extinct)

Nycticorax – night herons (6 species of which 4 extinct)

Butorides – herons (3 species)

Ardeola – pond herons (6 species)

Ardea – herons and egrets (14 species, including cattle egrets)

As of July 2023 the IOC lists 72 heron species, divided into 18 genera.[17]

  • Subfamily Tigriornithinae
  • Subfamily Cochleariinae
  • Subfamily Agamiinae
  • Subfamily Botaurinae
    • Genus Zebrilus – zigzag heron
    • Genus Ixobrychus – small bitterns (eight living species, one recently extinct)
    • Genus Botaurus – large bitterns (four species)
    • Genus Pikaihao – Saint Bathan's bittern (fossil, Early Miocene of Otago, New Zealand)
  • Subfamily Ardeinae
    • Genus Zeltornis (fossil, Early Miocene of Djebel Zelten, Libya)
    • Genus Nycticorax – typical night herons (two living species, four recently extinct; sometimes includes Nyctanassa)
    • Genus Nyctanassa – American night herons (one living species, one recently extinct)
    • Genus Gorsachius – Asian and African night herons (four species)
    • Genus Butorides – green-backed herons (three species; sometimes included in Ardea)
    • Genus Pilherodius – capped heron
    • Genus Zonerodius – forest bittern
    • Genus Ardeola – pond herons (six species)
    • Genus Bubulcus – cattle egrets (one or two species, sometimes included in Ardea)
    • Genus Proardea (fossil)
    • Genus Ardea – typical herons (11–17 species)
    • Genus Syrigma – whistling heron
    • Genus Egretta – typical egrets (7–13 species)
    • Genus undetermined
      • Easter Island heron, Ardeidae gen. et sp. indet. (prehistoric)
Fossil herons of unresolved affiliations
  • "Anas" basaltica (Late Oligocene of Varnsdorf, Czech Republic)
  • Ardeagradis
  • Proardeola – possibly same as Proardea
  • Matuku (Early Miocene of Otago, New Zealand)

Other prehistoric and fossil species are included in the respective genus accounts. In addition, Proherodius is a disputed fossil which was variously considered a heron or one of the extinct long-legged waterfowl, the Presbyornithidae. It is only known from a sternum; a tarsometatarsus that had been assigned to it actually belongs to the paleognath Lithornis vulturinus.


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Symbolic meaning in mysticism

In Buddhism, a heron symbolizes purity, transformation and the wisdom of the Buddha. In addition, as a bird that transcends elements – on the earth, in the water and in the air – the heron symbolizes the expansion of awareness and the ubiquity of consciousness.

In Native American culture, this bird symbolizes renewal, rejuvenation and rebirth – an ever present reminder that we are all a part of a larger cycle of life and death.

المراجع

  1. ^ Mayr, G. et al. (2018) A fossil heron from the early Oligocene of Belgium – the earliest temporally well-constrained record of the Ardeidae. Ibis, 161(1) DOI:10.1111/ibi.12600
  2. ^ أ ب ت ث ج ح خ د ذ ر ز س Martínez-Vilalta, Albert; Motis, Anna (1992). "Family Ardeidae (herons)". In del Hoyo, Josep; Elliott, Andrew; Sargatal, Jordi (eds.). Handbook of the Birds of the World. Volume 1: Ostriches to Ducks. Barcelona: Lynx Edicions. pp. 376–403. ISBN 978-84-87334-10-8.
  3. ^ Itoh, Singi (1991). "Geographical Variation of the Plumage Polymorphism in the eastern reef heron (Egretta sacra)" (PDF). The Condor. 93 (2): 383–389. doi:10.2307/1368954. JSTOR 1368954.
  4. ^ Watts, Bryan (1988). "Foraging Implications of Food Usage Patterns in yellow-browned night-herons" (PDF). The Condor. 90 (4): 860–865. doi:10.2307/1368843. JSTOR 1368843.
  5. ^ Meyerriecks, Andrew (1966). "Additional Observations on "Foot-Stirring" Feeding Behavior in herons" (PDF). The Auk. 83 (3): 471–472. doi:10.2307/4083060. JSTOR 4083060.
  6. ^ Delacour, J (1946). "Under-Wing Fishing of the black heron, Melanophoyx ardesiaca" (PDF). The Auk. 63 (3): 441–442. doi:10.2307/4080141. JSTOR 4080141.
  7. ^ Post, R.; Post, C.; F. Walsh (2009). "Little egret (Egretta garzetta) and grey heron (Ardea cinerea) Using Bait for Fishing in Kenya". Waterbirds. 32 (3): 450–452. doi:10.1675/063.032.0311. S2CID 85622885.
  8. ^ Robinson, S. (1994). "Use of bait and lures by green-backed herons in Amazonian Peru" (PDF). Wilson Bulletin. 106 (3): 569–571. JSTOR 4163462.
  9. ^ Dinsmore, James J. (1973). "Foraging Success of Cattle Egrets, Bubulcus ibis". American Midland Naturalist. 89 (1): 242–246. doi:10.2307/2424157. JSTOR 2424157.
  10. ^ أ ب Hilaluddin, Aisha S.; Khan, A.; Yahya, H.; Kaul, R. (2006). "Nesting ecology of Cattle Egrets and Little Egrets in Amroha, Uttar Pradesh, India" (PDF). Forktail. 22. Archived from the original (PDF) on 2011-06-10.
  11. ^ Kushlan, J. A. (2011). The terminology of courtship, nesting, feeding and maintenance in herons Archived 2019-10-24 at the Wayback Machine. heronconservation.org
  12. ^ Mehta, Kanishka; Koli, Vijay K.; Kittur, Swati; Sundar, K. S. Gopi (2024). "Can you nest where you roost? Waterbirds use different sites but similar cues to locate roosting and breeding sites in a small Indian city". Urban Ecosystems. 27.
  13. ^ خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة McCracken & Sheldon
  14. ^ خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة Sheldon1995
  15. ^ خطأ استشهاد: وسم <ref> غير صحيح؛ لا نص تم توفيره للمراجع المسماة Sheldon2000
  16. ^ Hackett SJ, Kimball RT, Reddy S, Bowie RC, Braun EL, Braun MJ, Chojnowski JL, Cox WA, Han KL, Harshman J, Huddleston CJ, Marks BD, Miglia KJ, Moore WS, Sheldon FH, Steadman DW, Witt CC, Yuri T (2008). "A Phylogenomic Study of Birds Reveals Their Evolutionary History". Science. 320 (5884): 1763–1768. Bibcode:2008Sci...320.1763H. doi:10.1126/science.1157704. PMID 18583609. S2CID 6472805.
  17. ^ أ ب ت Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2023). "Ibis, spoonbills, herons, Hamerkop, Shoebill, pelicans". IOC World Bird List Version 13.2. International Ornithologists' Union. Retrieved 19 September 2023.
  18. ^ أ ب Hruska, J.P.; Holmes, J.; Oliveros, C.; Shakya, S.; Lavretsky, P.; McCracken, K.G.; Sheldon, F.H.; Moyle, R.G. (2023). "Ultraconserved elements resolve the phylogeny and corroborate patterns of molecular rate variation in herons (Aves: Ardeidae)". Ornithology. 140 (2): ukad005. doi:10.1093/ornithology/ukad005.