Airone cenerino

Identificazione

The grey heron is a large bird, standing up to 100 cm (40 in) tall and measuring 84–102 cm (33–40 in) long with a 155–195 cm (61–77 in) wingspan. The body weight can range from .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}1.02–2.08 kg (2 lb 4 oz – 4 lb 9+1⁄4 oz). The plumage is largely ashy-grey above, and greyish-white below, with some black on the flanks. Adults have a white head and neck with a broad black supercilium that terminates in the slender, dangling crest, and bluish-black streaks on the front of the neck. The scapular feathers and the feathers at the base of the neck are somewhat elongated. Immature birds lack the dark stripe on the head and are generally duller in appearance than adults, with a grey head and neck, and a small, dark grey crest. The pinkish-yellow beak is long, straight, and powerful, and is brighter in color in breeding adults. The iris is yellow and the legs are brown and very long.<p>The main call is a loud croaking "fraaank", but a variety of guttural and raucous noises are heard at the breeding colony. The male uses an advertisement call to encourage a female to join him at the nest, and both sexes use various greeting calls after a pair bond has been established. A loud, harsh "schaah" is used by the male in driving other birds from the vicinity of the nest and a soft "gogogo" expresses anxiety, as when a predator is nearby or a human walks past the colony. The chicks utter loud chattering or ticking noises.

Tassonomia

Grey herons belong to the subfamily Ardeinae, along with the majority of extant species, which are known as the "typical herons". The grey heron was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae. He placed it with the cattle egret and the great egret in the genus Ardea and coined the binomial name Ardea cinerea. The scientific name comes from the Latin ardea meaning "heron" and cinereus meaning "ash-grey" or "ash-coloured".<p>Four subspecies are recognised:<p>It is closely related and similar to the North American great blue heron (Ardea herodias), which differs in being larger, and having chestnut-brown flanks and thighs; and to the cocoi heron (Ardea cocoi) from South America, with which it forms a superspecies. Some authorities believe that the subspecies A. c. monicae should be considered a separate species. It has been known to hybridise with the great egret (Ardea alba), the little egret (Egretta garzetta), the great blue heron and the purple heron (Ardea purpurea). The Australian white-faced heron is often incorrectly called a grey heron. In Ireland, the grey heron is often colloquially called a "crane".

Nome scientifico

Ardea cinerea

Autorità

Linnaeus, 1758

Ordine

Pelecaniformi

Famiglia

Ardeidae

Genere

Ardea

Areale e habitat

The grey heron has an extensive range throughout most of the Palearctic realm. The range of the nominate subspecies A. c. cinerea extends to 70° N in Norway and 66°N in Sweden, but its northerly limit is around 60°N across the rest of Europe and Asia, as far eastwards as the Ural Mountains. To the south, its range extends to northern Spain, France, central Italy, the Balkans, the Caucasus, Iraq, Iran, India, The Maldives and Myanmar (Burma). It is also present in Africa south of the Sahara Desert, the Canary Islands, Morocco, Algeria, Tunisia, and many of the Mediterranean Islands. It is replaced by A. c. jouyi in eastern Siberia, Mongolia, eastern China, Hainan, Japan, and Taiwan. In Madagascar and the Aldabra Islands, the subspecies A. c. firasa is found, while the subspecies A. c. monicae is restricted to Mauritania and offshore islands.<p>Over much of its range, the grey heron is resident, but birds from the more northerly parts of Europe migrate southwards, some remaining in Central and Southern Europe, others travelling on to Africa south of the Sahara Desert.<p>The grey heron is also known to be vagrant in the Caribbean, Bermuda, Iceland, Greenland, the Aleutian Islands, and Newfoundland, with a few confirmed sightings in other parts of North America including Nova Scotia and Nantucket.<p>Within its range, the grey heron can be found anywhere with suitable watery habitat that can supply its food. The water body must be either shallow enough, or have a shelving margin in it, so that it can wade. Although most common in the lowlands, it also occurs in mountain tarns, lakes, reservoirs, rivers, marshes, ponds, ditches, flooded areas, coastal lagoons, estuaries, and the sea shore. It sometimes forages away from water in pasture, and it has been recorded in desert areas, hunting for beetles and lizards. Breeding colonies are usually near feeding areas, but exceptionally may be up to eight kilometres (five miles) away, and birds sometimes forage as much as 20 km (12 mi) from the nesting site.

Migrazione

Migratori completi

Comportamento

Comportamento migratorio: Migratori completi.

Conservazione

Tendenza della popolazione

unknown