I will always remember my first encounter with grass snakes at Puxton Marsh.

It was the first year and the first day of the grazing animals project and I had the job of carrying out the daily animal welfare checks.

Nettles and balsam formed a thick, almost impenetrable tangle, which in places must have been more than two metres tall.

Looking at it, I wondered how on earth I was going to find the animals.

I was probably going to end up stung and scratched to ribbons just trying.

However, things did not turn out as badly as I had first feared.

The cattle had already pushed their way through the tangle, creating tunnels under the vegetation that I could easily follow. I soon found them.

On latter days, the cows started making more and more tunnels and it soon became a labyrinth in which finding cattle frequently took hours.

It was these tunnels through the marshland vegetation which left me having some of my best and most memorable encounters with grass snakes.

When I started to walk down the tunnels I looked up to see movement in the tangle of foliage above my head.

Intrigued, I looked and discovered to my disbelief grass snakes slithering above my head.

This was a fantastic sight and combined with the atmosphere of creeping through these dark green, marshy smelling tunnels is an experience that will always stay with me.

A few years have passed now and the grazing animals project has had quite an impact on the flora of Puxton Marsh.

Thick stands of nettle and balsam are no longer a feature and so this year, finding the animals has not been such a chore.

However, the spectacular tunnels have gone and with them the unique opportunity to view grass snakes in this unusual setting.

The grass snakes though, are thriving on the marsh, with more than a dozen being spotted during a short visit.

The grass snakes are an important - and to us humans harmless - part of the marshlands ecology.

To see them in such numbers really lifts my heart, particularly as in past years grass snakes have suffered so badly from loss of habitat and persecution, which has led to rapid declines in their numbers.