Azure raven

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Azure raven
Azure raven Cyanocorax caeruleus

Azure raven Cyanocorax caeruleus

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Corvoidea
Family : Corvids (Corvidae)
Genre : Blue raven ( Cyanocorax )
Type : Azure raven
Scientific name
Cyanocorax caeruleus
( Vieillot , 1818)

The Azure Jay ( Cyanocorax coeruleus , Syn. : Cyanocorax coeruleus ) is a bird art from the family of corvids . He mainly lives in the araucaria forest in southern Brazil . Azure ravens live in swarms and are divided into clans, which can stay together for up to two generations. During the breeding season, they build the nests together and ensure their own safety. The animals master a wide range of bird calls.

habitat

Habitat of the azure raven in southern Brazil

The azure blue lives in the Atlantic rainforest in the south of Brazil (from São Paulo to Rio Grande do Sul ) and northeast of Argentina ( Misiones and north of Corrientes ). These corvids can be found in large numbers in the araucarias forest, where they prefer the Brazilian araucarias ( Araucaria angustifolia ) to build nests and use them as a source of food.

features

The azure raven is approx. 40 cm long and has a powerful beak. The body's bright blue plumage color is in stark contrast to the black feathers on its head, the front of the neck, and the upper part of the chest. The feathers on the forehead are slightly ruffled, the eyes and beak are dark. The females are a bit smaller, however, otherwise there is no sexual dimorphism .

nutrition

Brazilian Araucaria seeds ( Araucaria angustifolia )

The azure raven was observed by residents of the araucaria forest area while eating the seeds of the Brazilian araucarias and is therefore considered to be the spreaders of the araucaria trees . The seeds are often not eaten immediately and occasionally germinate if they are lost in transit or forgotten in storage in old logs or bushes. But the azure ravens, like other corvids, are omnivores, and since they eat arthropods and fruits in addition to seeds , they are not as acutely threatened with extinction as the araucarias.

Reproduction

The breeding season goes from October to March, during this time the azure blue raven builds its nests preferably on the crowns of the Brazilian araucarias. The whole clan is responsible for building, cleaning and protecting the nest and the brood. The nests are 10–20 m high, have a diameter of around 40–50 cm and are flat. In the center there is a brood chamber with a diameter of 16–20 cm and a depth of 6–9 cm, which usually houses 3–5 eggs. The eggs are green-blue with small brown or gray spots evenly distributed on the surface. They are about 33 × 24 mm in size and 9 g in weight.

voice

Some animals living in groups have developed acoustic signals ( animal language ) to communicate with other animals . The Azure Ravens are adaptive birds that have a repertoire of 14 cries for various purposes. For example, there are special screams for announcing a predator , for determining the location during the flight, for communication between different swarms and for mating. The screams are clearly different from each other and can be combined.

threat

The IUCN lists this species as NT IUCN 3 1st svg(= Near Threatened - potentially endangered).

swell

literature

  • BL Reinert, MR Bornschein: Alimentação da Gralha-Azul (Cyanocorax caeruleus, Corvidae) , 1998, ORNITOLOGIA NEOTROPICAL 9: 213-217
  • L. dos Anjos: O ciclo anual de Cyanocorax caeruleus em floresta de araucária (Passeriformes: Corvidae) , 1991. Ararajuba 2: 19-23.
  • L. dos Anjos: Gralha-azul: biologia e conservação , Companhia de Seguros Gralha Azul, 1995, Curitiba.
  • L. dos Anjos, JME Vielliard: Repertoire of the acoustic communication of the azure jay Cyanocorax caeruleus (Vieillot) (Aves, Corvidae) , Revta bras. Zool. 10 (4): 559-750, December 1993

Individual evidence

  1. ↑ a b Cyanocorax coeruleus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed on 7 February, 2009.
  2. ↑ BL Reinert, MR Bornschein: Alimentação da Gralha-Azul (Cyanocorax caeruleus, Corvidae) , 1998, ORNITOLOGIA NEOTROPICAL 9: 213-217
  3. ↑ BL Reinert, MR Bornschein, R. Bóçon: Novas informacoes sobre o ninho eo ovo da gralha-azul, Cyanocorax caeruleus (Corvidae) , 1996 Ararajuba 4 (1): 32-34
  4. ↑ L. dos Anjos, JME Vielliard: Repertoire of the acoustic communication of the azure jay Cyanocorax caeruleus (Vieillot) (Aves, Corvidae) , Revta bras. Zool. 10 (4): 559-750, December 1993

Web links

Commons : Azure raven ( Cyanocorax caeruleus )  - Collection of images, videos and audio files