Avetorillo Común

Identificación

The little bittern has a length of 33–38 centimetres (13–15 in) and a wing span of 52–58 centimetres (20–23 in). It is the smallest of the breeding herons of Europe and is characterised by its tiny size, long and sharp bill and thick neck. The males are distinctively patterned and both sexes show pale forewing panels. The males have black with a faint green sheen on the crown, nape, back, tail and scapulars. The underparts are pale buff and the wing has a pinkish buff oval shaped panel which contrasts with the otherwise black wings and is formed by the inner wing coverts. The underwing is completely whiteish in colour. The female is duller than the male and has brownish black upperparts with paler feather margins visible at close range. The underparts of the female are not as clean as those of the male and are streaked with dark buff and brown. The female's wing panel is less obvious than the male's. The juveniles are duller and more rufous than the females and are more heavily streaked on both their upperparts and underparts, including their wing coverts.

Taxonomía

Carl Linnaeus described the little bittern in 1766. Member of a cosmopolitan superspecies with I. exilis (North and South America), I. sinensis (Asia) and I. dubius (New Guinea, AUS). I. [m.] minutus itself consists of three clearly differentiated subspecies (groups) to which all-species status could be assigned:<p>The Australian little bittern (I. dubius) and the extinct New Zealand little bittern (I. novaezelandiae) were formerly considered subspecies of the little bittern.<p>Comparative studies, especially on shouting / courtship behavior and genetics, are lacking.

Nombre científico

Botaurus minutus

Autoridad

(Linnaeus, 1766)

Orden

Pelecaniformes

Familia

Ardeidae

Género

Botaurus

Distribución y hábitat

The little bittern is native to the Old World, breeding in Africa, central and southern Europe, western and southern Asia, and Madagascar. Birds from temperate regions in Europe and western Asia are migratory, wintering in Africa and further south in Asia, while those nesting in the tropics are sedentary. It is rare north of its breeding range.<p>In Britain there were intermittent reports of breeding in the nineteenth century, and again in 1946 and 1957, but none of these records were proven. The first proven British breeding record is from Yorkshire in 1984, and the second from the Avalon Marshes in Somerset in 2010, by 2017 this species had been present in this area for nine consecutive years.

Migración

Complete migrants

Comportamiento

The little bittern is crepuscular, skulking and normally solitary. It feeds on fishes, amphibians and insects which are caught within reedbeds or at their edges by the bird slowly stalking the prey. The male claims a territory in the Spring, advertising his presence with a deep barking or croaking call and the monogamous pair remain together for at least one breeding season. Eggs are laid in a nest situated in dense reedbeds, rushes or bushes above the water from the middle of May and there is a single brood which is normally 5-6 eggs. These are incubated for 17–19 days and the chicks are fledged after 25–30 days.<p>In Europe the little bittern is a migratory species, crossing the Mediterranean from Africa in the early Spring and arriving in their breeding wetlands from mid April onwards. The return to Africa occurs in August and September and there are normally only a few juveniles left in Europe by October. The European breeders migrate as far south as the Eastern Cape and Transvaal.

Conservación

Tendencia poblacional

declining