Humboldt Penguin

Identificazione

Humboldt penguins are medium-sized penguins, growing to 56–70 cm (22–28 in) long and a weight of 2.9 to 6 kg (6.4 to 13.2 lb). The sex of the Humboldt penguin cannot be recognised via differences in plumage, as they are monomorphic. The male is heavier and larger than the females. Their sex can be determined via head width and bill length; the male has a longer bill than the female. While all the Spheniscus penguins are close to each other in size, the Humboldt penguin is the heaviest species in the genus, with 123 females weighing 4.05 kg (8.9 lb) on average and 165 males averaging 4.7 kg (10 lb). Humboldt penguins have a black head with a white border that runs from behind the eye, around the black ear-coverts and chin, and joins at the throat. They have blackish-grey upperparts and whitish underparts, with a black breast-band that extends down the flanks to the thigh. They have a fleshy-pink base to the bill. Juveniles have dark heads and no breast-band. They have spines on their tongue which they use to hold their prey.<p>The Humboldt penguin has different calls that it uses to communicate in different ways. The function of its calls are consistent among Spheniscus species. If an individual comes too close to an adult Humboldt penguin, the Yell is a warning call which is followed by pecking or chasing if ignored. A higher density of penguins leads to more territorial and aggressive behaviours, which leads to more Yells. The Throb is a soft call between pairs at the nest, used by incubating birds when their mates return to the nest. The Haw is a short call given by juveniles alone in the water and by paired birds when one is on the water and the other is on land. It has significant individual variation in duration and frequency. The Bray is a long call used to attract a mate and advertise a territory during the pre-laying and pre-hatching periods. It is an individually distinct call in all variables: syllables per call, duration, inter-syllable intervals, duration of syllables and frequency. When calling, the bird points its head upwards and flaps its flippers slowly. The Courtship Bray is similar to the Bray, however a different posture is assumed and is given synchronously by pairs during the pre-laying period: the birds stand together pointing their necks and head up, with flippers out to the side. The Peep is given by chicks begging for food.<p>Most penguins moult between mid-January and mid-February, however the initiation varies with latitude and favourable conditions such as food abundance. Humboldt penguins are confined to land until they finish moulting. They become hyperphagic during the pre-moulting period. The feathers are lost and replaced within 2 weeks.

Tassonomia

Genere: Spheniscus; famiglia: Spheniscidae; ordine: Sphenisciformes.

Nome scientifico

Spheniscus humboldti

Autorità

Meyen, 1834

Ordine

Sfenisciformi

Famiglia

Spheniscidae

Genere

Spheniscus

Areale e habitat

The Humboldt penguin is a top predator endemic to the west coast of South America.<p>The Humboldt penguin's breeding distribution ranges from southern Chile along the dry and arid coastal regions of the Atacama Desert to subtropical Isla Foca in north Peru. Its range is restricted to the coast and offshore islands affected by the Humboldt current, which provides a continuous supply of nutrients and food, thus supporting huge populations of seabird. In Chile, the most important breeding colony is at Isla Chañaral.

Migrazione

Migratori completi

Comportamento

Comportamento migratorio: Migratori completi.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione