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. 

What a Rail!

They are a bird that is actually fairly common in the watery habitats of Britain, but one that very few people tend to see. You may however have heard it on many occasions but not realised, wondering what is that harsh screech coming from the dense vegetation. Most are more familiar with their less secretive cousins, the coot and moorhen. While ringing and nesting in the reed beds at Cranwich we often hear this secretive and elusive bird but today’s trip would end with a rather special encounter as we caught one in one our traps. It is the water rail. 

A busy ringing session had seen us process just over 50 birds, numbers bumped up by young recently fledged robins with their speckled brown plumage and long tailed tits with their chocolatey brown faces and deep red eye ring. With the wind picking up and the nets down most of the team had drifted away, to spend their Saturday afternoon elsewhere either checking other sites for nests or even heading home for a nap (well we had all been up since 4 am!). It was the last check of the trap, one final chance to see if we had been successful. The water rail is not the easiest of species to catch, and only three have been ringed on site since we began monitoring years ago. It appears though that Lee seems to have cracked it, with two of those three birds having been ringed this year. It is likely that we only have two or three pairs on site so it’s not like there are huge numbers to go for. However with some careful monitoring of where calling birds have been heard, and with the discovery of a beautiful nest, we are building a picture of the territories on site. Lee suspected that there was another pair at the end of one of our net rides, and so the trap had been set. 

A beautiful water rail nest

Standing in the slightly muddy ride, surrounded by the tall reeds and willows I listen to the sounds of the reed bed. The now constant chatter of reed warblers, their nesting in full swing, the distinctive song of the male cuckoo joined by the bubbling call of females, the song of reed bunting, and the persistent high pitched twitter of those families of long tailed tit. At the end of the ride Lee emerges from the reeds, at first glance he appears to be empty handed, before revealing from behind his back the very bird I had been hoping for. It is a water rail! 

Back at the car, I process the bird with care. It is wriggly, threatening to give me the slip. It is so much smaller than expected. Compared with the coot and moorhen I have held and seen up close, it is tiny! And so much daintier. The classic flailing of legs, scratching out with clawed feet is typical of handling any rail though. It is the perfect opportunity to take a really good look at this bird, one that if you are lucky enough to see it is usually over in a flash. Its long curved bill is red, as is on close inspection its dark eye. The sides of its head, neck and its underparts are a steely, bluish grey, a deep chestnut brown streak runs from the top of its head right the way onto its back where the feathers have deep black centres. Its flanks are barred with white and black. It is a beautiful bird. 

A beautiful water rail

The assessment reveals that this bird is in fact already ringed. Far from being a disappointment this may be the most interesting fact. The bird was ringed at the other side of the pool where we caught it, only a month or so earlier. It seems the bird’s breeding territory may be larger than originally suspected and that the males (which is what we suspect this to be) move around more than we initially thought. It is a very interesting piece to the Cranwich water rail population puzzle.

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We return the bird to the edge of the reed bed where we caught it, where on letting it go it wastes no time in scampering away into the dense growth. Once more becoming just that elusive screech from among the reeds. 

Larking Around

Only recently had the trees been felled, leaving a mosaic of sandy soil, mossy grass, patches of dark heather and tangles of twigs and branches. From the main road this seemingly barren landscape sloped up to the tall dark green conifer trees that surrounded the patch on three sides. While it may seem an extreme change this is the cycle of this forest where trees are planted and felled on a rotation. Add to that the process of returning areas to more natural grassland heath and more of such open areas can be found amongst the blocks of trees. For 100 years ago this landscape was totally different. The entire area was open with grass and heather heaths, open sandy areas, low intensity arable farming and abandoned fields. Rabbits in particular were farmed in large enclosed warrens. Following the First World War the Forestry Commission began the process of afforestation, planting hundreds of hectares of Scots and then Corsican pine to provide a reserve of timber for a country whose trees had been as ravaged by the demands of war as its people. Today the whole of Thetford Forest is a patchwork of pine plantations, broadleaved trees and heath land, and is managed not only for timber, but for recreation and wildlife.

Woodlark carrying food for its chicks

Such barren looking patches of clear fell and grassy heath provide important habitat for a number of scarce breeding birds, including the woodlark. The tufts of short grass, close proximity to bare soil and good high posts for singing, are all perfect for woodlarks to set up home during the summer.

Knowing an area is good for breeding woodlark, seeing a pair there with the male’s sweet song of melancholy notes which includes a lu-lu-lu, giving the bird part of its scientific name Lullula arborea, is one thing. Finding its nest is a whole different ball game, one of patience and knowledge. Even knowing there is a nest within a few square feet in front of you, it is still hard to see, such is the excellent cryptic nature of nest and chick.

A beautiful woodlark nest

But there nestled amongst the grassy stems is a tightly weaved nest, in which four greyish brown chicks are squeezed in. What a privilege to be allowed to approach and view such a nest, which is done under strict licence. Monitoring of this species has never been more important. Since the early 1980s the range and population of woodlark in the UK has actually increased following a severe decline, but it is still comparatively rare and its breeding range restricted. Forestry plantations form a key part of this increase, but interestingly in the Forestry areas of Norfolk and Suffolk numbers of woodlark are in decline. Understanding more about the movements, breeding success and habitat use of birds in such areas is contributing to maintaining and increasing woodlark numbers by feeding into management plans for the forest. To that end this, and other nests are being monitored from egg laying to fledging, and the chicks are being colour ringed to look at movements of birds and where they subsequently return to breed.

Feed me!

On returning these four chicks to their snug nest and stepping carefully away to a safe distance, we watch as both parent birds call with a soft ‘tlewee’ to each other, beaks full of recently foraged insects, before swooping in back to the nest. We turn to leave, happy birds, happy chicks, happy people.