Monday, 5 October 2015

Snakes in the grass

Along the grassy margins of the pools, nestled amongst the tall grass, reeds, alders and willows at the waters edge, and near to the open spaces of short grass and sandy soil at Cranwich there are a number of dark, corrugated sheets. The warm sunshine of a sunny September beats down on the black material, warming the soil beneath. It had been a cool night and the surrounding grass, reeds and leaves were damp, water droplets glistening in the bright sunlight. It was with great care that we approached these corrugated sheets, gently lifting them to discover the secrets hidden in the warm, darkness. As the light flushes the area, a quick movement catches the eye, and it requires even quicker reactions to catch it’s source. Lifting the beautiful animal into the light the sun glistens off dark, brownish grey scales that when catching the light look almost bronze. Its belly is pale yellow. Down its side and especially underneath there are jet black scales forming a pattern that is distinctive to each individual. The head has a bright yellow and black collar, and a gleaming eye with round pupil. From the mouth a dark, forked tongue darts in and out tasting the air. It is a beautiful Grass Snake. It coils around the hand holding it, supple and sleek, there is nothing slimy about it, it is all muscle. The tongue continually tasting the surrounding air. 

A beautiful Grass Snake

Checking more refugia reveals more snakes, each a Grass Snake but each distinctively different. A different arrangement to the pattern of black scales, a different variation to the colour of the brown scales. One is much darker, another an almost olive brown colour. The largest is just over a metre in length, the smallest reaches from tip of finger to elbow, and is as thin as a pencil.

Checking more refugia

The habitat here is perfect for them, plenty of long grass close to water, providing a ready supply of amphibians, the snakes preferred prey. 

The series of refugia have been purposely placed around the site since the spring when the snakes would have come out of hibernation and sought out food and a mate. Throughout the summer a student has been monitoring the snakes catching, measuring and photographing them. Like with the bird population we want to know how many snakes are using the site, and like with birds we use the technique of ‘mark recapture’ to do this. However unlike with birds where we add a small metal ring with a unique number inscribed, with snakes it is simply a case of taking its picture. The unique pattern to the black markings on the belly of each snake will be more than enough to identify individuals, much like a human finger print.

Stunning markings on a Grass Snake

As the summer has waned into autumn, even with its final warm flourish, the number of snakes being found has begun to drop, as many start seeking out places to hibernate, a safe haven for the cold winter months ahead. For now with the warm autumnal sun beating down, it is time to release the snakes back into the long grass or the nearby water, ready to continue hunting before they too head for hibernation. 

1 comment:

  1. Wow so great to get so close, I've seen a few grass snakes over the years but would love to have more experiences (been many years now).

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