| 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) | |
 | |
| Synonyms[2] | |
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Ctenotus leonhardii, known by thecommon namesLeonhardi's ctenotus,Leonhardi's skink, and thecommon desert ctenotus, is aspecies oflizard in thesubfamilySphenomorphinae of thefamilyScincidae. The species is found in a range of arid and semi-arid regions throughout mainlandAustralia.[2] Named after German anthropologistMoritz von Leonhardi in 1919, it belongs to thegenusCtenotus, one of the largestgenera of lizards in Australia.[3]
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 running down the vertebral row ofdorsal scales.[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 otherCtenotus species, Leonhardi's ctenotus has four limbs, five digits on each limb, and smooth scales, with a distinctive row of small scales near the ear.[7]
Leonhardi's ctenotus adults can grow to a maximumsnout-to-vent length (SVL) of 7.9 cm (3.1 in),[8] weighing on average 9.14 g (0.322 oz).[4] Males and females grow to a similar size, unlike many otherCtenotus species which demonstratesexual dimorphism.[8] Leonhardi's ctenotus is one of the slower growingCtenotus species, reaching maturity at 18 months.[9] Juveniles grow at a rate of 0.22 mm (0.0087 in) per day from hatching and commonly live for 5 years, though the oldest recorded specimen was 7 years old.[9]
Leonhardi's ctenotus was named after German anthropologistMoritz von Leonhardi by herpetologistRichard Sternfeld in 1919.[10] The species is in the Scincidae family (skinks), belonging to the genusCtenotus.[4] In the past this genus was included within the genusSphenomorphus, before being raised togeneric 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 ofspecies groups that are based on morphological similarity and which include theCtenotus leonhardii group, to which Leonhardi's ctenotus belongs.[11]
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]
Leonhardi's ctenotus has been found in a range of aridhabitat types including open grasslands, sandplain deserts dominated byspinifex, 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.[12] Withinchenopod-dominated ecosystems, this species has been found to be significantly associated with high densities ofMaireana species.[8] It is a burrowing skink and shelters in burrows with at least two entrances.[4]
Like many other lizards, Leonhardii's ctenotus is 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).[12] However, unlike some other lizard species Leonhardi's ctenotus is diurnal and active during the hottest hours of the day[12] As a result, it has the highest active body temperature recorded for any skink species.[12]
The home range of Leonhardi's ctenotus ranges from 20-60 square meters (215–646 square feet), similar to the home range size for otherCtenotus species.[8] Leonhardi's ctenotus is carnivorous, with a generalist insectivore diet.[8] It is an active forager, 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.[13] Unlike most other Ctenotus species, Leonhardi's ctenotus rarely eats termites but will when other prey are scarce.[14][13] Major native predators of Leonhardi's ctenotus includeGould's goanna(Varanus gouldii) and therusty 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.[15]
Densities of Leonhardi's ctenotus have been found to be negatively associated with increased rainfall, with peak densities occurring during prolonged dry periods.[15] However, individual body condition has been found to deteriorate in dry years compared to years with higher rainfall.[14] Leonhardi's ctenotus is often sympatric with numerous otherCtenotus species in the arid zones, with up to 14 species from this genus sometimes co-occurring in one area.[6][3]
Leonhardi's ctenotus reproduces by sexual reproduction.[16] Spermatogenesis, ovulation and mating occur most typically in spring,[17] though breeding can occur anytime between October and February.[16] The species is oviparous, laying 5 eggs on average.[16] However,clutch size is highly variable and dependent upon environmental conditions, with no successful reproduction occurring in some years.[8] Furthermore, clutch size is variable across different regions, with Leonhardi's ctenotus in South Australia commonly laying only 2 eggs,[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]
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]
