Ctenotus leonhardii
| Ctenotus leonhardii | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Family: | Scincidae |
| Genus: | Ctenotus |
| Species: | C. leonhardii
|
| Binomial name | |
| Ctenotus leonhardii (Sternfeld, 1919)
| |
| |
Ctenotus leonhardii, known by the common names Leonhardi's ctenotus, Leonhardi's skink or common desert ctenotus, is a species of skink found in a range of arid and semi-arid regions throughout mainland Australia.[2] The species was named after German anthropologist Moritz von Leonhardi in 1919 and belongs to the genus Ctenotus, one of the largest genera of lizards in Australia.[3]
Description
[edit]
Leonhardi's ctenotus is a small, slender terrestrial skink.[4] This species is typically brown to ochre-brown above, sometimes with a dark brown stripe down the vertebra.[5] There are pale stripes running from the eyes down to the tail on either side, often with a dark brown edge above.[5] Below this stripe is a darker, sometimes black lateral stripe with a complex pattern of white spots over the top.[6] From the groin there is a pale cream stripe running towards the flanks, with a series of white spots near the arms and a continuing pale lateral stripe down the length of the tail.[5] Like all other Ctenotus species, Leonhardi's ctenotus has four limbs with five digits each and smooth scales, with a distinctive row of small scales near the ear.[7]
Leonhardi's ctenotus adults can grow to a maximum of 7.9 cm long,[8] weighing on average 9.14g.[4] Males and females grow to a similar size, unlike many other Ctenotus species which demonstrate sexual dimorphism.[8] Leonhardi's ctenotus is one of the slower growing Ctenotus species, reaching maturity at 18 months.[9] Juveniles grow at a rate of 0.22mm per day from hatching and commonly live for 5 years, though the oldest recorded specimen was 7 years old.[9]
Taxonomy
[edit]Leonhardi's ctenotus was named by German anthropologist Moritz von Leonhardi in 1919.[citation needed] The species is in the Scincidae family (skinks), belonging to the genus Ctenotus.[4] In the past this genus was included within the Sphenomorphus, before being raised to generic status in 1964.[3] Ctenotus species are commonly called 'comb-eared skinks' due to the shape of the small scales near the ear.[7] Ctenotus is one of the largest genera of lizards in Australia,[3] containing nearly 100 species.[5] It is one of the most abundant genera of lizards in arid and semi-arid Australia,[8] and one of the most diverse genera of terrestrial vertebrates globally.[6] Ctenotus is further divided into a number of 'species groups' that are based on morphological similarity and which includes the Ctenotus leonhardii group, to which Leonhardi's ctenotus belongs.[10]
Distribution
[edit]Leonhardi's ctenotus is found in the arid and semi-arid regions of central Western Australia, the lower half of the Northern Territory, northern South Australia, south-west Queensland and north-west New South Wales.[5] It is a common species in these regions, often seen basking in the sun in the morning in open areas.[4]
Habitat and ecology
[edit]Leonhardi's ctenotus has been found in a range of arid habitat types including open grasslands, sandplain deserts dominated by spinifex, and semi-arid shrublands.[3][5] It is particularly abundant in acacia and chenopod dominated shrublands [3] and prefers habitats with grassy groundcover.[4] Spinifex tussocks provide protection from predators, harsh environmental conditions and an abundant supply of insects.[11] Within chenopod-dominated ecosystems, this species has been found to be significantly associated with high densities of Maireana species.[8] It is a burrowing skink and shelters in burrows with at least two entrances.[4]
Like many other lizards, Leonhardii's ctenotus are able to survive in harsh desert environments due to the use of ectothermy which allows metabolic inactivity to occur in harsh conditions (i.e. aestivation).[11] However, unlike some other lizard species Leonhardi's ctenotus is diurnal and active during the hottest hours of the day [11] As a result, they have the highest active body temperature recorded for any skink species.[11]
The home range of Leonhardi's ctenotus ranges from 20-60m, similar to the home range size for other Ctenotus species.[8] Leonhardi's ctenotus is carnivorous, with a generalist insectivore diet.[8] They are active foragers, foraging within the open spaces between grasses and other groundcover plants for prey.[3] The majority of foraging occurs around midday, with the bulk of the diet being made up of cockroaches, spiders, grasshoppers, silverfish, beetles, weevils, and the larvae of moths and butterflies.[12] Unlike most other Ctenotus species, Leonhardi's ctenotus rarely eats termites but will when other prey are scarce.[13][12] Major native predators of Leonhardi's ctenotus include Gould's goanna (Varanus gouldii) and rusty desert monitor (Varanus eremius).[3] High densities of introduced predators like foxes have also been associated with lower recapture success in mark-recapture surveys of Leonhardi's ctenotus, suggesting predation by this species.[14]
Densities of Leonhardi's ctenotus have been found to be negatively associated with increased rainfall, with peak densities occurring during prolonged dry periods.[14] However, individual body condition has been found to deteriorate in dry years compared to years with higher rainfall.[13] Leonhardi's ctenotus is often sympatric with numerous other Ctenotus species in the arid zones, with up to 14 species from this genus sometimes co-occurring in one area.[6][3]
Reproduction
[edit]Leonhardi's ctenotus reproduce by sexual reproduction.[15] Spermatogenesis, ovulation and mating occur most typically in Spring,[16] though breeding can occur anywhere between October and February.[15] They are oviparous, laying 5 eggs on average.[15] However, litter size is highly variable and dependent upon environmental conditions, with no successful reproduction occurring in some years.[8] Furthermore, litter size is variable across different regions, with Leonhardi's ctenotus in South Australia commonly raising only 2 young,[8] while the same species in the Great Victoria Desert regularly lays up to 7 eggs.[3] Juvenile survival is often low, with only 10-30% of juveniles surviving to adulthood.[9]
Conservation status
[edit]Leonhardi's ctenotus is listed as a species of Least Concern under the IUCN [2] and is a common and widespread species within its preferred habitat.[4]
References
[edit]- ^ How, R.; Gaikhorst, G.; Ford, S.; Cowan, M. (2017). "Ctenotus leonhardii". IUCN Red List of Threatened Species. 2017: e.T178448A101747235. doi:10.2305/IUCN.UK.2017-3.RLTS.T178448A101747235.en. Retrieved 18 November 2021.
- ^ a b Ctenotus leonhardii at the Reptarium.cz Reptile Database. Accessed 22 March 2015.
- ^ a b c d e f g h i Pianka, Eric R. (1969). "Sympatry of Desert Lizards (Ctenotus) in Western Australia". Ecology. 50 (6): 1012–1030. doi:10.2307/1936893. JSTOR 1936893.
- ^ a b c d e f g "Species: Ctenotus leonhardii (Leonhardi's Ctenotus)". bie.ala.org.au. Retrieved 2022-06-16.
- ^ a b c d e f Cogger, Harold (2014). Reptiles and Amphibians of Australia (Seventh ed.). CSIRO Publishing. ISBN 978-0-643-10978-0.
- ^ a b c Rabosky, Daniel L.; Talaba, Amanda L.; Donnellan, Stephen C.; Lovette, Irby J. (2009-11-01). "Molecular evidence for hybridization between two Australian desert skinks, Ctenotus leonhardii and Ctenotus quattuordecimlineatus (Scincidae: Squamata)". Molecular Phylogenetics and Evolution. 53 (2): 368–377. doi:10.1016/j.ympev.2009.06.020. ISSN 1055-7903. PMID 19580879.
- ^ a b "Ctenotus - Australian Lizards". The Australian Museum. 2022. Retrieved 2022-06-16.
- ^ a b c d e f g h Read, J. L. (1998). "The ecology of sympatric scincid lizards (Ctenotus) in arid South Australia". Australian Journal of Zoology. 46 (6): 617. doi:10.1071/ZO97063. ISSN 0004-959X.
- ^ a b c James, Craig D. (1991). "Growth Rates and Ages at Maturity of Sympatric Scincid Lizards (Ctenotus) in Central Australia". Journal of Herpetology. 25 (3): 284–295. doi:10.2307/1564586. JSTOR 1564586.
- ^ King, Max; Horner, Paul; Fyfe, Greg (1988). "A new species of Ctenotus (Reptilia: Scincidae) from central Australia, and a key to the Ctenotus leonhardii species group". The Beagle: Records of the Museums and Art Galleries of the Northern Territory. 5 (1): 147–153. doi:10.5962/p.271276. ISSN 0811-3653. S2CID 133456928.
- ^ a b c d Pianka, Eric R. (1981), "Diversity and adaptive radiations of Australian desert lizards", Ecological Biogeography of Australia, Monographiae Biologicae, vol. 41, Dordrecht: Springer Netherlands, pp. 1375–1392, doi:10.1007/978-94-009-8629-9_50, ISBN 978-94-009-8631-2, retrieved 2022-06-17
- ^ a b James, Craig D. (1991). "Temporal variation in diets and trophic partitioning by coexisting lizards (Ctenotus: Scincidae) in central Australia". Oecologia. 85 (4): 553–561. doi:10.1007/bf00323768. ISSN 0029-8549. PMID 28312503. S2CID 5687047.
- ^ a b Schlesinger, Christine A.; Christian, Keith A.; James, Craig D.; Morton, Stephen R. (2010). "Seven lizard species and a blind snake: activity, body condition and growth of desert herpetofauna in relation to rainfall". Australian Journal of Zoology. 58 (5): 273. doi:10.1071/ZO10058. ISSN 0004-959X.
- ^ a b Read, John L.; Kovac, Kelli-Jo; Brook, Barry W.; Fordham, Damien A. (2012). "Booming during a bust: Asynchronous population responses of arid zone lizards to climatic variables". Acta Oecologica. 40: 51–61. doi:10.1016/j.actao.2011.09.006.
- ^ a b c Mesquita, Daniel O.; Colli, Guarino R.; Costa, Gabriel C.; Costa, Taís B.; Shepard, Donald B.; Vitt, Laurie J.; Pianka, Eric R. (2015). "Life history data of lizards of the world: Ecological Archives E096-058". Ecology. 96 (2): 594. doi:10.1890/14-1453.1. ISSN 0012-9658.
- ^ Goldberg, Stephen R. (2008). Notes on the reproduction of four species of Ctenotus: C. Leonhardii, C. Pantherinus, C. Quattuordecimlineaturs and C. Schomburgkii (Scincidae). Herpetofauna, 38 (1): 8-13.