Ansonia inthanon
This species is found in Thailand, but not within Bangkok itself
Doi Inthanon (© Benjamin Tapley) 
Doi Inthanon (© Michael Cota) 
Doi Suthep (© Jon Hakim) 
Doi Suthep (© Jon Hakim)
English name: Inthanon Stream Toad
Scientific name: Ansonia inthanon
Thai name: คางคกหัวยอินทนนท (Kang-kok huai inthanon)
Description: To 26mm long. A small slender-limbed stream toad, dark brown above with prominent yellow speckling on the lower lip, belly, and limbs. Tiny warts evenly cover the entire dorsal surface. Often stands with its body elevated well off the ground, emphasizing the yellow markings and slender front legs.
Similar Species: Marbled Cascade Frog has thicker legs, larger eyes, and a clear “true frog” body type/gestalt.
Habitat: Found in proximity to mountain torrents and cascades, so far only above 900m in elevation. Tends to hide in vegetation, caves, and under logs.
Range: Is only known from a few select mountainous regions in Chiang Mai and Kanchanaburi Provinces.
Place in the ecosystem: Its diet is unknown, though it likely feeds on small invertebrates in or near the water. It may be preyed upon by snakes and larger frogs.
Danger to humans: Not dangerous.
Conservation status and threats: The Inthanon Stream Toad is only known from a limited area in northern Thailand, and is rarely seen thought that may be do to its cryptic nature. This frog’s suitable habitat includes several protected areas and thus is it labeled as Least Concern by the IUCN, but populations and habitat are thought to be decreasing due to the expansion of agriculture into its range.
Interesting Facts: I encountered one of the Inthanon Stream Toads pictured above on four different occasions, but it was always tucked away in deep recesses behind rock and water in a mountain stream which made photography difficult.
The Inthanon Stream Toad was first discovered in 1998 from a single locality in Chaing Mai Province. In 2004 a second locality for the species was found in Kanchanaburi . I found the individual described above on Doi Suthep, thereby representing only the third locality known for the species. Until further study is done, this frog cannot be absolutely confirmed as Ansonia inthanon and it is in fact possible that it represents a separate species – for example, the large yellow dot on the back does not appear typical of the Doi Inthanon populations.
I want to acknowledge Stephen Mahoney for pointing me towards Ansonia.
References:
A New Ansonia from Northern Thailand
IUCN Red List: Ansonia inthanon
AmphibiaWeb – Ansonia inthanon
Thailand Office of Environmental Planning and Policy: A Checklist of Amphibians and Reptiles in Thailand
Stephen Mahoney, personal communication
Reptiles and Amphibians of Thailand 