Scarlet Skimmer

Many thanks to members of the dragonfly group on Bird Forum for identifying it as a Scarlet Skimmer Orthetrum testaceum.

This Scarlet Skimmer was photographed in the late afternoon in long grass alongside the main road leading to the top of the Kaeng Krachan National Park in Thailand. The altitude was approximately around 600 metres above sea level.

Scarlet Skimmer is an Asian freshwater dragonfly species. It is distributed throughout India, Indonesia, Malaysia, Philippines, Singapore and Thailand. One subspecies has been described, Orthetrum testaceum soembanum.

References:

Wikipedia
Dragonflies of Kaeng Krachan1
Dragonflies of Kaeng Krachan2