The lovely BAMBOO VIPER . In Hong Kong specifically we have Trimeresurus albolabris.
This post is about Male and female vipers.
Males - as shown in the photos in this blog - are smaller than females with a distinctive white stripe above the lip running laterally down the length of the body giving rise to it's formal common name the 'White-Lipped Viper'. Both male and female have characteristically triangular shaped head with yellow/gold eyes containing vertical pupils.
As always, information provided by and taken from our sister site
These snakes are active at night and occasionally roost in bushes during the day. The Bamboo Viper is an ambush predator that will wait in a single position ready to strike. They are a viper and have relatively long retractable fangs and will bite readily at anything that comes within range that they think is a food item. Generally not prone to give chase but will hold their ground if they feel cornered. Not actively aggressive but will not hesitate to bite if touched or scared. A bite from a Bamboo Viper should be considered very serious and medical attention should be sought immediately. Although not known to be deadly serious damage can occur from a bite even if treated and complications can always arise. (Check out Adam's excellent videos here : https://youtu.be/DqQ7WdrlzXo
This was one of 5 vipers and six snakes that we found on our night walk in SaiKung in late October.