Egernia
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Cunningham Skink ( Egernia cunninghami ), southeastern Australia |
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| Scientific name | ||||||||||||
| Egernia | ||||||||||||
| Gray , 1838 |
The spikytail skinks of the genus Egernia live in Australia and often show highly developed social behavior.
Systematics
The Egernia group, which originally contained the genera Corucia , Cyclodomorphus , Egernia and the blue- tongue skink ( Tiliqua ), and which is closely related to the helmet skink ( Tribolonotus ), is morphologically well defined. While the genera Corucia , Cyclodomorphus and the blue- tongue skink ( Tiliqua ) can be easily defined morphologically, the remaining species have been combined in the genus Egernia . But as early as the 19th century it was believed that this genre was very heterogeneous. The exact relationships were only clarified by molecular biological investigations in 2008. In the course of these investigations, the genus Egernia was split into the four genera Bellatorias , Egernia , Liopholis and Lissolepis . This article describes the genus Egernia in the above, narrower sense.
features
The species of the genus Egernia are medium-sized to large lizards that reach an actual body length (snout to anus) of 10–24 cm when grown up. The head and body are mostly compressed vertically. There are 24–46 rows of scales in the middle of the body. The scales on the back vary from species to species: there are both smooth and multi-keeled scales as well as prickly scales. The row of scales under the eyes is incomplete. The eyes are relatively small, their lids the same color as the scales surrounding them.
species
The genus Egernia knows 17 species, namely:
- Egernia cunninghami (Gray, 1832) - Cunningham's Skink: lives in groups of 2–26 individuals in Southeast Australia, the tail is included up to 46 cm long, has approx. 6 young in January / February, prefers rocky terrain, herbivores. Enemies: snakes. Cunningham's Skink can reach an age of over 20 years and isprotectedin South Australia .
- Egernia cygnitos Doughty, Kealley & Donnellan, 2011
- Egernia epsisolus (Günther, 1875) - dwarf spiny-tailed skink, lives in family groups in southern and western Australia, the tail is enclosed up to 16 cm long, has 2–3 young, preferably deserts and bushes.
- Egernia douglasi Glauert, 1956 -Called Kimberley Crevice-Skink in Australia. Liveson trees in rocky terrain on Western Australian's north coast of Kimberley and its tail is up to 34 cm long. Brings live young into the world.
- Egernia eos Doughty, Kealley & Donnellan, 2011
- Egernia formosa Fry, 1914 -Called Goldfield's Crevice Skink in Australia. It lives in Western Australia in rocky terrain on trees and in bushland and its tail is up to 20 cm long. Bring into the world 2-3 living young.
- Egernia hosmeri Kinghorn, 1955 - Hosmer's spiky-tailed skink. Lives in forest areas of the Northern Territory and Queensland in family groups of 2–9 individuals and the short tail is included up to 24 cm long. Bears 2 live cubs in late August. The herbivore is 12–24 years old.
- Egernia kingii (Gray, 1838) - King's Skink. Lives on the ground in family groups in open wooded areas of Western Australia and includes a long tail up to 36 cm long. From being omnivorous in youth, it later changes to herbivore. Bears 4–6 live youngsters in April.
- Egernia mcpheei Wells & Wellington, 1984 -Called McPhee's Egernia in Australia. Lives in family groups of 5–8 individuals in rocky terrain and sometimes also on trees in coastal areas of Queensland and New South Wales. It becomes the long tail included up to 28 cm long and has 3–5 young in January / February.
- Egernia napoleonis (Gray, 1838) - is called the South-western Crevice-Skink and lives in open forests in Western Australia. It grows up to 28 cm long with its rather long tail and gives birth to 2–4 young in spring. This skink is omnivorous. The diamond python ( Morelia spilota variegata ) follows it .
- Egernia pilbarensis Storr, 1978 - Not much is known about this skinkart that lives in the stony grasslands of Western Australia. Including its long tail, it is up to 28 cm long.
- Egernia richardi Peters, 1869 - not much is known about this skinkart, which occurs in western Australia and which, including its long tail, is up to 21 cm long.
- Egernia rugosa (De Vis, 1888) - Yakka Skink. With a total length of 40 cm, the Yakka Skink is the largest species of the genus Egernia . No genetic data was available for this rare ground-floor skink in Queensland woodlands. It is provisionallyassigned tothe genus Egernia due to its morphological properties (e.g. small eyes). Because of its size, some authors see a relationship to the species of the genus Bellatorias , such as the giant spiked skink . It is protected in Queensland.
- Egernia saxatilis Cogger, 1960 - This small, rocky forest terrain preferring skink iscalled Black Rock Skink in Australia. It has 1–5 young in spring. It is an omnivore and ispursuedby both snakes ( Australian copper heads ( Austrelaps ramsayi )) and the giant bag marten ( Dasyurus maculatus ).
- Egernia stokesii (Gray, 1845) - The Stoke's Skink occurs in several subspecies throughout most of Australia. It has a very short tail and is up to 25 cm long. In spring he gives birth to an average of 5 young. It reaches an age of 10-25 years. His enemies include snakes, birds, foxes and cats. The subspecies E. stokesii aethiops is becoming extinct in Western Australia.
- Egernia striolata (Peters, 1870) - The small tree prickly skink lives on trees in open woodlands in eastern Australia. He's an omnivore. Snakes and cats chase after him.
Way of life
As far as is known, the Egernia species have a long lifespan. They ripen late. All species are viviparous. Several species live in family groups, with the young staying with their parents until maturation (Stokes' Skink: 5 years). In the case of Stokes' Skink, the death rate in young animals is very high at 66% in the first year of life; there is no information about other species. The mating behavior of E. stokesii , E. cunninghami and E. saxatilis points - also genetically - to strict monogamy. The animals live in long-term, stable family groups. These Egernia species avoid inbreeding due to certain behavioral mechanisms. Related animals recognize each other, which is quite unusual in scale creepers. Most species seek shelter in crevices, caves on the ground or under leaves. Many mark their area with their droppings, which are always deposited in the same place.
evolution
It is believed that the ancestor of the genus Egernia , possibly Mabuya multifasciata , immigrated to Australia in the Pliocene over the land bridge of the Torres Strait from New Guinea and became native to the rainforests of Queensland. Ice ages and dry spells then contributed to the diversification of these skinks, which subsequently spread across Australia.
Individual evidence
- ^ MG Gardner et al. a .: Molecular systematics of social skinks: phylogeny and taxonomy of the Egernia group (Reptilia: Scincidae). Zoological Journal of the Linnean Society Vol. 154, 2008, 781-794.
- ↑ DRHorton. Evolution of the genus Egernia (Lacertilia: Scincidae). Journal of Herpetology, Vol. 6, 1972, pp. 101-109.
literature
- DG Chapple: Ecology, life-history, and behavior in the Australian Scincid genus Egernia , with comments on the evolution of complex sociality in lizards. Herpetological Monographs, Volume 17, 2003, 145-180.
- Harold G. Cogger: Reptiles & Amphibians of Australia. 6th edition. Ralph Curtis Books, Sanibel, Florida 2000, ISBN 0-88359-048-4 .
- MG Gardner, AF Hugall, SC Donnellan, MN Hutchinson and R. Foster: Molecular systematics of social skinks: phylogeny and taxonomy of the Egernia group (Reptilia: Scincidae). Zoological Journal of the Linnean Society Vol. 154, 2008, 781-794.
- Doughty, Paul; Luke Kealley, and Stephen C. Donnellan 2011. Revision of the Pygmy Spiny-tailed Skinks (Egernia depressa species-group) from Western Australia, with descriptions of three new species. Rec. West. Austr. Mus. 26: 115-137
Web links
- The reptile database Family Scincidae
- Australian Faunal Directory [1]
- Picture gallery of Western Australian skinks [2]
- Egernia in The Reptile Database