Wall's vine snake (''Ahaetulla isabellina'') is a species of tree

snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the southern Western Ghats of

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

Taxonomy

It was formerly considered a subspecies of '' A. nasuta'', which is now considered to only be endemic to

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

. A 2020 study found ''A. nasuta'' to be a species complex of ''A. nasuta

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

'' as well as '' A. borealis'', '' A. farnsworthi'', ''A. isabellina'', and '' A. malabarica'', elevating ''A. isabellina'' to species. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

is a reference to the isabelline yellow coloration of the species' dorsal body in live condition, which distinguishes it from other species in the complex. Ahaetulla isabellina

Geographic range

This species is distributed in the southern Western Ghats in

Tamil Nadu Tamil Nadu (; , TN) is a States and union territories of India, state in southern India. It is the List of states and union territories of India by area, tenth largest Indian state by area and the List of states and union territories of India ...

and

Kerala Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...

south of the

Palghat Gap Palakkad Gap or Palghat Gap is a low mountain pass in the Western Ghats between Coimbatore in Tamil Nadu and Palakkad in Kerala. It has an average elevation of with a width of . The pass is located between the Nilgiri Hills to the north ...

, from the

Anaimalai Hills The Anamala or Anaimalai, also known as the Elephant Mountains, are a range of mountains in the southern Western Ghats of central Kerala ( Idukki district, Ernakulam district, Palakkad district, Thrissur district) and span the border of wes ...

south to at least

Sivagiri, Kerala Sivagiri is an area in Varkala Municipality of Thiruvananthapuram district in Kerala. It is a pilgrimage centre of Varkala Town where the tomb, or samadhi, of Sree Narayana Guru is situated. It is a place where Guru built the Sarada Templ ...

, although more work is needed to determine the southern limit of the species' range.

Habitat

This species is found in

evergreen forests An evergreen forest is a forest made up of evergreen trees. They occur across a wide range of climatic zones, and include trees such as conifers and holly in cold climates, eucalyptus, Live oak, acacias, magnolia, and banksia in more temperate zon ...

of the Western Ghats from ~550 m to 1475 msl.

References

{{Taxonbar, from=Q102109396 Ahaetulla Reptiles of India Snakes of Asia Endemic fauna of the Western Ghats Reptiles described in 1910