Egernia

Cunningham Skink ( Egernia cunninghami ), southeastern Australia

The spiny-tailed skinks of the genus Egernia live in Australia and often show a highly developed social behavior.

System

The Egernia group that originally contained the genera Corucia Cyclodomorphus, Egernia and Blauzungenskinke ( Tiliqua ), and closely with the Helmskinken ( Tribolonotus ) is related, is morphologically well defined. While the genera Corucia Cyclodomorphus and Blauzungenskinke ( Tiliqua ) morphologically can be defined easily, and the remaining species were grouped together in the genus Egernia. But already in the 19th century, it was believed that this genus is very heterogeneous. The exact relationships but were only clarified by molecular biological studies in 2008. In the course of these investigations, the genus Egernia in the four genera Bellatorias, Egernia, Liopholis and Lissolepis was split. This article describes the genus Egernia in the above, the narrower sense.

Features

The species of the genus Egernia are medium to large lizards, grow reach an actual body length ( snout to anus) of 10-24 cm. Head and body are mostly vertically compressed. In the middle of the body are 24-46 rows of scales. On the back, the scales vary from species to species: kick it both smooth and keeled scales several times as well as sting shed. The scales range under the eyes is incomplete. The eyes are relatively small, their eyelids are the same color as the scales surrounding it.

Species

The genus Egernia knows 14 types, namely:

• Egernia cunninghami (Gray, 1832) - Cunningham's Skink: lives in groups of 2-26 individuals in south-eastern Australia, is the tail included up to 46 cm long, throws in January / February about 6 boy, preferably rocky terrain, herbivore. Enemies: Snakes. Cunningham's Skink reached an age of over 20 years and is protected in South Australia.
• Egernia depressa ( Günther, 1875) - Dwarf Stachelschwanzskink, lives in family groups in South and Western Australia, the tail is included up to 16 cm long, 2-3 throws boy, preferably deserts and bush terrain.
• Egernia Douglasi ( Glauert, 1956) - If called in Australia Kimberley Crevice Skink. Live at Western Australians North Coast Kimberley in rocky terrain on trees and the tail is included up to 34 cm long. Bring live young into the world.
• Egernia formosa ( Fry, 1914) - If called in Australia Goldfields Crevice Skink. He lives in Western Australia in rocky terrain on trees and in bushland and the tail is included up to 20 cm long. Bring 2-3 live young into the world.
• Egernia hosmeri ( Kinghorn, 1955) - Hosmer 's spiny-tailed skink. Living in the forest areas of the Northern Territory and Queensland in family groups of 2-9 individuals and is the short tail included up to 24 cm long. Bring in late August 2 live young into the world. The herbivores is 12-24 years old.
• Egernia kingii (Gray, 1838) - King's Skink. Living in family groups in open forest areas of Western Australia on the ground and the long tail is included up to 36 cm long. From omnivorous in his youth, he later changed to herbivores. Bring in 4 to 6 April live young into the world.
• Egernia mcpheei ( Wells & Wellington, 1984) - If called in Australia McPhee's Egernia. Living in family groups of 5-8 individuals in rocky terrain and partly also on trees in coastal areas of Queensland and New South Wales. He is the long tail included up to 28 cm long and throws in January / February 3 to 5 boy.
• Egernia Napoleonis (Gray, 1838) - is called South - western Crevice Skink and lives in Western Australia in open woods. He is with his very long tail up to 28 cm long and throws in spring 2-4 boy. This skink is an omnivore. He recreates the diamond python (Morelia spilota variegata ).
• Egernia pilbarensis ( Storr, 1978) - This in rocky grasslands living in Western Australia Skinkart Not much is known. Counting your long tail it is up to 28 cm long.
• Egernia richardi (Peters, 1869) - also about this occurring in Western Australia Skinkart, which included its long tail up to 21 cm long, not much is known.
• Egernia rugosa ( De Vis, 1888) - Yakka Skink. The Yakka Skink is 40 cm in total length, the largest species of the genus Egernia. From this rare, bottom-dwelling woodland of Queensland Skink no genetic data were available. It is tentatively assigned to the genus Egernia basis of morphological characteristics (eg. Small eyes ). Some authors see a relationship to species of the genus Bellatorias, about the giant Stachelskink due to its size. It is protected in Queensland.
• Egernia saxatilis ( Cogger, 1960) - preferring This small rocky forest terrain Skink is called in Australia Black Rock Skink. He throws 1-5 Young in the spring. He is an omnivore and will both snakes (Australian copperheads ( Austrelaps ramsayi ) ) as well as the Giant Quoll ( Dasyurus maculatus ) followed.
• Egernia stokesii (Gray, 1845) - The Stoke 's Skink comes in several subspecies throughout most of Australia before. He has a very short tail and is long up to 25 cm. In the spring he brings an average of 5 young. He reached the age of 10-25 years. His enemies include snakes, birds, foxes and cats. The subspecies E. stokesii aethiops is in Western Australia on the way out.
• Egernia striolata (Peters, 1870) - The Little Tree Stachelskink lives in eastern Australia in open woodland on trees. He is an omnivore. Ask Him for snakes and cats.

Way of life

The Egernia species have - so far known - a long life. They mature late. All species are viviparous. Several species live in family groups, with the boys until their maturation in the parents remain ( Stokes ' Skink: 5 years). When Stokes ' Skink, the death rate in young animals is about 66% in the first year of life is very high, from other species is it explained. The mating behavior of E. stokesii, E. cunninghami and E. saxatilis has - even genetically - to strict monogamy out. The animals live in long-term, stable family groups. Avoiding these types of Egernia but inbreeding due to certain behavioral mechanisms. Related animals recognize each other, which is quite unusual for Schuppenkriechtieren. Most species seek shelter in rock crevices, caves on the ground or under leaves. Many mark their territory by their droppings, which is always stored in the same place.

Evolution

It is believed that the ancestor of the genus Egernia, possibly Mabuya multifasciata, has migrated across the land bridge in the Pliocene of the Torres Strait coming from New Guinea to Australia and native to the rainforests of Queensland was. Ice ages and droughts have then contributed to the diversification of these skinks, which have spread in the sequence all over Australia.