Troides cuneifera, the Mountain Birdwing, is a large butterfly belonging to the swallowtail family, Papilionidae, found in the Thai-Malay Peninsula, Sumatra, Java and Borneo.

Being very similar to Troides amphrysus, the butterfly was originally described as Ornithoptera amphrisius var. cuneifera. The first to separate the two species was Pieter Cornelius Tobias Snellen in 1889. In Sumatra and Java it is a highlands species occurring up to an altitude of 2,000 metres (6,600 ft), but it occurs as low as 300 metres (980 ft) in the Thai-Malay Peninsula. The species is in decline in Sumatra and Java due to human activities such as increased cultivation.

Troides cuneifera tantalus remains one of the great mysteries of the birdwings. The taxon is known from only one male and one female. When described, the specimens were claimed to originate from Kala Bula Hills or Kala Bala Hills, north Borneo.

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