Reptiles and Amphibians of Thailand

Thailand's Snakes, Lizards, Turtles, and Frogs

Haas’s Bronzeback

Dendrelaphis haasi

This snake is found in Thailand but not in Bangkok
Haas's Bronzeback Dendrelaphis haasi malaysia
Haas’s Bronzeback in peninsular Malaysia Malaysia (© Orion Herp Adventure)

English name: Haas’s Bronzeback
Scientific name: Dendrelaphis haasi
Thai name:

Description: To 95cm long. An extremely slender snake with a narrow neck which enlarges as a threat display. Body is tan to light olive-brown with blue skin between the scales which show more when enlarged. There is a dull cream ventrolateral stripe which is barely visible in some specimens. Stripe is not edged in black. Head is orangish-brown to tan with a narrow black eyestripe that sometimes ends before reaching the neck, which instead has oblique black bars. Eye is small compared to many other Bronzebacks. Belly is very pale yellow or green, approaching white.

Relevant scale counts: 15 rows of midbody scales with enlarged vertebral scales. 161-173 ventrals and 126-153 subcaudals.

Similar Species: Painted Bronzeback is more robust with a brown head, a thicker eyestripe, and a more distinct ventrolateral stripe bordered in black.
Blue Bronzeback has a thicker eyestripe and lacks the ventrolateral stripe.
Elegant Bronzeback has a thicker eyestripe and lacks the ventrolateral stripe.
Banded Bronzeback has a yellowish neck (most visible when inflated) and lacks the ventrolateral stripe.
Kopstein’s Bronzeback has a reddish neck (most visible when inflated), lacks the ventrolateral stripe, and is heftier.

Range: From southern Thailand through Malaysia, Singapore, and Indonesia.

Habitat: Moist lowland forests, often near water.

Contribution to the ecosystem: Feeds on lizards and frogs. Eaten by birds of prey and larger snakes.

Danger to humans: This species is not dangerous to humans.

Conservation status and threats: No known conservation issues, though it is seen less often than several other Bronzebacks.

Interesting facts: Haas’s Bronzeback was only recently described as a species in 2008, as specimens were previously confused with the Painted Bronzeback despite the differences in size, head color, eye stripe, and ventrolateral stripe. In the original description the species was listed as occurring in Malaysia, Singapore, and Indonesia, and that is still the official range. However, the naturalist Rushen Bilgin, who collects field reports from across Thailand through his work as developer of the Thai National Parks pages, has contact with three different herpers who have confirmed the species in four localities across two Thai provinces. In a country like Thailand where the range of many species is poorly understood, Rushen’s work to consolidate sightings has been invaluable.

References:
Ecology Asia: Haas’s Bronzeback
Rushen Bilgin pers. comm.
Contributions to a review of the Dendrelaphis pictus complex – 1. Description of a sympatric species
A new species of Dendrelaphis from Southeast Asia

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