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© 2004-2018 Thomas Jäkel
Adult Kalimantan (Indonesia) male and female. The female still features juvenile patterns, such as the red post-ocular stripe and whitish transversal bars on the back.
Same male as shown above. Male vipers from Borneo often display only white markings on the back. The juvenile red portion disappears during transition to adulthood. Furthermore, eyes are usually light brown, not yellow like in the western Malaysian or Sumatran forms.
Same female as above, some months later, and gravid for the first time. Note the swollen hind portion of the body.
Subadult female, in transition to adulthood
Adult female from northwestern Borneo (West Kalimantan), collected between Singkawang and Sambas.
Adult male from northwestern Borneo (West Kalimantan), collected between Singkawang and Sambas.
Large adult female (90 cm) from northwestern Borneo, collected between Singkawang and Sambas.
Adult male from northwestern Borneo, collected between Singkawang and Sambas. Although adult males from Borneo generally do not show red dots on the back, males from this population were an exception. Also note the irregular, whitish spots on parts of the body, which appeared to be fungal growth, indicating that this individual’s health was probably not in a good shape. 
Adult female from northwestern Borneo
Female  from northwestern Borneo in transition to adulthood
Wagler’s Viper Site - Kalimantan (Borneo)
© 2004-2018 Thomas Jäkel
Ophiotropics.com
Wagler’s Viper Site - Kalimantan (Borneo)
Adult Kalimantan (Indonesia) male and female. The female still features juvenile patterns, such as the red post-ocular stripe and whitish transversal bars on the back.
Same male as shown above. Male vipers from Borneo often display only white markings on the back. The juvenile red portion disappears during transition to adulthood. Furthermore, eyes are usually light brown, not yellow like in the western Malaysian or Sumatran forms.
Same female as above, some months later, and gravid for the first time. Note the swollen hind portion of the body.
Subadult female, in transition to adulthood
Adult female from northwestern Borneo (West Kalimantan), collected between Singkawang and Sambas.
Adult male from northwestern Borneo (West Kalimantan), collected between Singkawang and Sambas.
Large adult female (90 cm) from northwestern Borneo, collected between Singkawang and Sambas.
Adult male from northwestern Borneo, collected between Singkawang and Sambas. Although adult males from Borneo generally do not show red dots on the back, males from this population were an exception. Also note the irregular, whitish spots on parts of the body, which appeared to be fungal growth, indicating that this individual’s health was probably not in a good shape. 
Adult female from northwestern Borneo
Female  from northwestern Borneo in transition to adulthood