Sunday, 25 May 2014

Vipera berus...

Adders, loathed by many and loved by a few. Very misunderstood creatures. I happen to love them and when you see them up close they are very impressive snakes. They are our only venomous snake and only representative of the old world viper family in the UK. Their venom is cytotoxic and has a haemorrhagic effect, which means it breaks down the vascular system causing internal bleeding, which in turn speeds up the digestion process of its prey. This huge female (around 65cm) was found on a tin refuge trying to warm up. She's also about to slough her old skin, if you look at her eyes they should be bright red but have instead a milky appearance caused by the old lens separating from the new one underneath. It was early morning when I took these and she was freezing cold, a great time to study them closely as they normally disappear very quickly when humans or predators approach.

Showing the characteristic 'V' shape on the back of the head
R. Harris
Warming in the sun, defensive position: R. Harris
Portrait showing the milky coloured eye, a sign that
sloughing is about to begin.

Female Adder: R. Harris
Ready to strike! Check out the keeled dorsal scales
The deeply forked chemo-sensory tongue  'tastes' the air
and is placed onto the Jacobson's organ in the roof
of the mouth for analysis.
Again showing the milky haze on the eyes.
Adders are particularly vulnerable at this stage
and tend not to move about too much until the
shedding is well under way.
Showing the head scales - note the asymmetrical scales
just behind the two apical scales above the snout.
And a very short (hand held) video clip...

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