Английская Википедия:Gehyra versicolor
Gehyra versicolor, commonly known as the eastern tree dtella. is a native Australian gecko occurring in temperate forests of eastern Australia.[1]
Taxonomy
It was formerly considered as conspecific with Gehyra variegata until classified as a separate species in 2014.[1]
Description
G. versicolor is a medium grey to brown gecko with complex dark and white markings.[1] It can have faint to prominent white spots or short lines adjoining on the posterior margins of dark markings.[1] The G. Versicolor has a flattened body and pads at the end of each toe.[2] They contain 8-11 pairs of supralabial scales.[1] The max body length is 57mm.[1] The adult snout length is between 37-54mm.[1] The length of full-grown tail is between 40-58mm.[1] The G. versicolor and G. variegate are extremely difficult to extinguish based on external morphology as they share the characteristics.[1] The species are distinguished due to their difference in karyotype and distribution.[1]
Evolutionary History
Historically, the genus Gehyra has been difficult to delimit due to their continent-wide distribution, similar morphological characteristics and high genetic diversity among the group.[3] In the 1970s and the 1980s, chromosomal studies found that there was substantial heterogeneity and independent patterns of karyotypic diversity within some of the species of Gehyra [1]. In 1982, the three species found were the G. variegate, G. monitum, and G. nana. In 2014, molecular genetic studies found that there were five separate species within the Gehyra genus.[1] G. monitum was split into two new species known as G. moritzi and G. pulingka [1]. The G. variegate Eastern Australian populations are now known as the G. versicolor [1].
The most recent ancestor of the genus Gehyr migrated from Asia to Australia during the late-Eocene to mid- Miocene (13-33 million years ago).[4][5] It was highly adapted to tropical environments and the division of the genus occurred when they migrated to the arid Kimberly region.[5]
Distribution
G. versicolor is widespread over the Eastern part of Australia.[1] Its range stretches from northern Victoria through the Great Dividing Range of New South Wales and up to North Queensland.[1] It stretches west into most of South Australia and into central Northern Territory.[1] It is not found in Western Australia or Tasmania.
Habitat
G. versicolor is reliant on native, mature, woody vegetation for habitat.[6] These semi-arid macrohabitats are widespread usually fall under the categories of dry woodland, desert or savannah woodland.[6] Vegetation is often composed of Red Gum, Pine- Buloke, Mallee and Black Box Woodland.[6]
The microhabitat of G. versicolor is characterised of thick peeling bark, fallen logs, fallen timber, leaf litter and rocks.[7] The species is both arboreal and saxicoline, relying on both the group and mid-canopy habitats.[7]
Ecology
Reproduction
Male and female G. versicolor reach sexual maturity at 2 years of age but do not begin breeding until 3 years old.[8] Females lay a single egg twice per year.[2] The first egg is laid in late spring and the second egg is laid in mid-summer.[2] Eggs are dispersed away from parent habitat and are usually laid under protective logs, bark or rock formations.[2] Eggs hatch approximately 60–80 days after they are laid.[2]
Behaviour
G. versicolor is primarily nocturnal but is known to be active during the day to thermoregulate.[2] Like all reptilian species, G. Versicolor is cold-blooded and must thermoregulate through behavioural actions, such as sunning themselves.[8] Breeding and growth are limited to the warmer months within a year and the species undergo a state of torpor during the colder winter months.[8]
Males are territorial and only one can occur per tree. Males often share a habitat with one or two females.[8] Like most geckos, they are tolerating of young and will share their microhabitat with them for long periods of time.[8]
G. versicolor have limited dispersal movements.[8] The largest movements occur when the female deposit their eggs within a different microhabitat.[8] Young also disperse when finding vacant and suitable microhabitats.[8]
G. versicolor, like all species of the genus Gehyra, can detach their tail as defensive mechanism and regrow it back.[9] When a G. versicolor is stressed, they drop their tail in an attempt to distract and escape from predators.[9]
Diet
G. versicolor is an omnivore that preys on a variety of arthropods including beetles, spiders and crickets [4]. They also rely on sap from gum bleeds due to its high nutrient intake [5]. G. Versicolor will continuously lick sap and are more commonly found on vegetation with significant gum bleeds such as the A. Victoriae [5].
Competition and predation
G. versicolor have limited competition with native species.[8] The geckos, Oedura ocellata Boulenger and the Heteronotia binoei (Gray) compete for the same macrohabitat but have different microhabitat and food resources.[8] Termites are a competing native species with the G. versicolor as they degrade microhabitats used by the gecko.[8]
G. versicolor are known to be a common food resource for many native and invasive predators.[8] They are predated by red foxes and feral cats (invasive), marsupial mice, kookaburras, ravens, butcher-birds and larger lizards and skinks (native).[8]
Ecological role
G. versicolor play a vital role within their ecosystem. They are an abundant food resources for many predators, including a variety of birds, reptiles and mammals.[8] They are also responsible for pollination and seed dispersal for many native vegetative species.[10] Whilst looking for food, the gecko often rubs against plant stigmas and allows for cross-pollination between other species and populations.[10]
Threats and conservation status
G. versicolor is categorised at least concern on the ranking of conservation status.[11] It has a stable and highly abundant population.[11] However, the G. versicolor is especially vulnerable to habitat loss and fragmentation.[6] They are an interior species that rely on continuous, mature, native habitat.[6] They are not effective dispersers, so are unable to migrate if their habitat is targeted by land-clearing.[6] It was found that G. versicolor completely avoid agricultural landscapes and edge habitat due to the high rates of predation.[6]
References
- ↑ 1,00 1,01 1,02 1,03 1,04 1,05 1,06 1,07 1,08 1,09 1,10 1,11 1,12 1,13 1,14 1,15 1,16 Шаблон:Cite journal
- ↑ 2,0 2,1 2,2 2,3 2,4 2,5 Шаблон:Cite book
- ↑ Шаблон:Cite journal
- ↑ Шаблон:Cite journal
- ↑ 5,0 5,1 Шаблон:Cite thesis
- ↑ 6,0 6,1 6,2 6,3 6,4 6,5 6,6 Шаблон:Cite journal
- ↑ 7,0 7,1 Шаблон:Cite journal
- ↑ 8,00 8,01 8,02 8,03 8,04 8,05 8,06 8,07 8,08 8,09 8,10 8,11 8,12 8,13 Шаблон:Cite journal
- ↑ 9,0 9,1 Шаблон:Cite journal
- ↑ 10,0 10,1 Шаблон:Cite journal
- ↑ 11,0 11,1 Шаблон:Cite web
