Western whip snake

Hierophis viridiflavus 

(Previously Coluber viridiflavus)

Couleuvre verte et jaune

The Western whip snake is present in the southern three quarters of France

and they are difficult to confuse with any other snake in this country. As their French name implies they are predominantly dark green with yellow dashes or bands which are transverse on the main part of their body and are longitudinal towards the tail, although as can be seen in the photos various forms exist depending on the stage of development with young snakes up to about 45cm being a grey / brown with a marbled head.  Growing to as much as 2 metres they can be large snakes when mature with prominent eyes and round pupils.

Juvenile Western Whip Snake

They occupy all types of habitat

but have a preference for dry, quiet areas – open woodlands and land which is left to scrub or fallow, sometimes to be found near rivers or other wet areas. They are extraordinary hunters and their prey varies with local availability but it will predominately take small mammals, small birds, frogs, lizards etc. They have also been known to eat adders and even their own species. 
Juvenile western whip snake France
Juvenile with tail bitten off by a cat

They are a powerful snake

though normally discreet they can be obstinate and quite aggressive, thrashing the ground with their tails and hissing when angered, sometimes tilting their head back and then striking and "biting" with force but they are of no serious concern to humans and given the chance will always flee rapidly. They are also agile climbers weaving their way rapidly through bushes and hedgerows. Frequently they or their shed skins are found in peoples attics or roof spaces where they can enjoy safety and heat. 
When snakes are about to shed their skin their eyes appear blue or milky as the skin that covers them becomes detached - they don't have eyelids. 

Hibernation generally takes place from October until April

using underground cavities, low cavities in or under trees and stumps, beneath stone walls etc. The period of hibernation is variable and is temperature driven meaning that they can be active in late winter in some regions on warmer sunny days.

Coupling takes place in May and can result in violent fights between males for a female, this can also occur between the sexes. During copulation the partners roll and twist themselves around each other, keeping their heads raised upright. Between 5 and 20 eggs are deposited under stones, old tree stumps or in rotting vegetation in June/July, the young hatching 6 to 8 weeks later.

All French snakes benefit from full protected status

They are locally threatened by a high accidental mortality on roads, especially close to urban or tourist areas, but this is not considered to be a major threat to the species overall. They are also persecuted throughout their range despite this being illegal because people mistakenly believe them to be venomous.