Species information
Scientific name: Diploderma polygonatum
Japanese name: キノボリトカゲ
Chinese name: 琉球龍蜥
English name: Ryukyu tree lizard
Origin: The nominate subspecies is distributed in the Amami Islands and Okinawa Islands. The Sakishima subspecies is found in the Miyako Islands and Yaeyama Islands, while the Yonaguni subspecies is found on Yonaguni Island.
Ecology and description
This genus was previously named Japalura (a true climbing lizard found in South Asia) but was revised to Diploderma in 2018 study.
Reference:
Wang, K., Che, J., Lin, S., Deepak, V., Datta-Roy, A., Jiang, K., Jin, J., Chen, H. & Siler, C. D. (2018).
“Multilocus phylogeny and revised classification for mountain dragons of the genus Japalura s.l. (Reptilia: Agamidae: Draconinae) from Asia.”
Zoological Journal of the Linnean Society, 185(1): 246–267.
Ryukyu tree lizard has several subspecies, including the Taiwanese Diploderma polygonatum (yellow-throated Japalura).
- Ryukyu tree lizard Diploderma polygonatum
- Okinawa tree lizard (Ryukyu tree lizard nominate subspecies) Diploderma polygonatum polygonatum
- Sakishima tree lizard (Ryukyu tree lizard Sakishima subspecies) Diploderma polygonatum ishigakiense
- Yonaguni tree lizard (Ryukyu tree lizard Yonaguni subspecies) Diploderma polygonatum donan
- Multiple-ridged lizard (yellow-throated Japalura/Ryukyu tree lizard multiple ridges subspecies) found in northern Taiwan Diploderma polygonata xanthostoma
Okinawa tree lizard (Diploderma polygonatum polygonatum):
Distributed in the Okinawa Islands and Amami Islands, male lizards reach a total length of about 25cm, females about 20cm. Male lizards often have bright green individuals and are not difficult to spot in Okinawa. This species is not designated as a rare animal by the Okinawa Prefectural Government. Some individuals have been taken to mainland Japan, after which they may be abandoned or escape. As of 2023, populations were also found in Hamamatsu City, Aichi Prefecture.
References:
Field photographs taken during our tours, with observation dates
During our 【Herping】 tour, there’s an opportunity to see Okinawa tree lizards sleeping on branches at night. In our 【Forest Walk】 tour, you might spot individuals active on tree trunks. They are more often seen during the summer when daytime temperatures exceed 25 degrees, and are hard to find after winter.
Sakishima tree lizard (Diploderma polygonatum ishigakiense):
Distributed in Miyako and Yaeyama Islands, including Ishigaki, Iriomote, and Kohama. Male lizards are about 20cm long, females about 17cm, and they are smaller than the nominate subspecies, with both sexes showing mainly brown coloration. They are not difficult to spot on Ishigaki, but their numbers have been significantly reduced on Miyako Island due to predation by the invasive Japanese weasel (Mustela itatsi).
Yonaguni tree lizard (Diploderma polygonatum donan):
Exclusively found on Yonaguni Island, its population is considerable. Males have white spots, while females have green scales. Inside the mouth of the Yonaguni tree lizard is flesh-colored.
