Monday, 14 January 2019

A Slimbridge Miscellany 12th January 2019

I have always had an affection for Jack Snipe. For me their shy and reclusive habits, the wonderfully cryptic plumage and the many happy memories they engender in me make them a true favourite.

It goes back a fair way to when I was just eighteen and training as a BTO ringer at Hersham Sewage farm in Surrey. The farm is long gone but in those days it was an old fashioned farm with long filter beds, filled with reeds and sedge that provided an ideal habitat for Jack and Common Snipe in winter and the highlight of any ringing session was to trap one or more Jack Snipe and have the pleasure of examining them in the hand and admire their beautiful plumage.They are not just streaked buff and brown, for their upperparts are subtly glossed iridescent green and purple, unlike the Common Snipe.

The origin of the name is thought to be from the small size of the bird as compared to the larger Common Snipe. For instance the smallest ball used in bowls is called 'a jack' and fishermen will refer to small pike as 'jack pikes.'

The scientific binomen is Lymnocryptes minimus.   Lymnocryptes comes from the Ancient Greek word  limne meaning 'marsh' and kruptos meaning 'hidden.' Minimus is from Latin meaning 'smallest.'

Jack Snipe are a long distance migrant and many come to winter in Britain from their breeding areas in northern Europe, Scandinavia and northern Russia. Others migrate to spend their winter on the Atlantic coasts of Europe and the Mediterranean. Some have been found to originate from north of Moscow or in Finnish Lapland and winter as far away as Zambia or northern Cameroon in the heart of Africa whilst others hatched in eastern Siberia  migrate to southeastern China or southern India. Extreme vagrants have even been found in the New World; four times in the USA and once in Labrador.

A hint of the origins of the Jack Snipe at Hersham came when I retrapped a bird that had been ringed in Norway.

The world population in 2003 was  estimated to be above one million individuals and it is  considered to be currently unthreatened

The Jack Snipe in winter leads a hidden and solitary existence. Its cryptic plumage perfectly mimics its environment and allows it to hide successfully from most predators and remain invisible up to less than a metre away. So confident are they of their supreme camouflage they will crouch immobile even when they are clearly visible in unsuitable terrain or out in the open.

Unlike Common Snipe the Jack Snipe, when flushed, does not rise like a missile and career off into the sky with a harsh cry but rises almost in a whisper of wings  from right under your feet, diffident and silent and drops down almost immediately only a short distance away. 

Being mainly nocturnal they are secretive and hard to observe in the open during daytime so an exceptional individual that has been, on occasions, observable during the daylight hours from a Hide at Slimbridge WWT (Wildfowl and Wetlands Trust) during the last week had me preparing a trip to renew an acquaintance which would be both a delight and revive many happy memories.

The first day I  could manage to get away was Saturday, not the ideal day to visit such a popular venue as Slimbridge but I had no choice. The prospect of sitting in a Hide, something I do not like due to the inevitable noise, distraction and disturbance from the other occupants was not appealing but there was no choice if I wished to see the Jack Snipe. However the lure of seeing a Jack Snipe and a lot of other good birds as well overcame any reservations on that score.

Being a member of WWT I can get into the Hides before they officially open at 9am so I entered he grounds via the members sidegate and made my way to the Martin Smith Hide to join just three other birders looking out onto an area of water, mud, reeds and grass but there was no sign of the Jack Snipe.

My view from the Hide.The Jack Snipe frequented the small patch of triangular
 green just right of centre. The Tack Piece is the grass area beyond the fence line

I was not overly surprised and sat down to await developments. I was sure the Jack Snipe would show itself in time. About twenty minutes had passed when one of the birders in the hide found it on an area of wet grass and muddy fringes right in front of the hide, feeding with a couple of Common Snipe right at the water's edge but very much obscured by small blades of reed and grass. The Common Snipe were much more obliging although they too can at times be hard to see but today one was particularly co operative.

Common Snipe
We kept an eye on the Jack Snipe but it never really came out into the open and eventually it scuttled off at speed, in a crouching run, back into some taller reeds, alarmed by a Carrion Crow flying low over its head.

That was all I saw of it for some time before it re emerged at the further side of the scrape, still well hidden and went to sleep next to a female Mallard. By now it was past nine am and the Hide began to fill up dramatically and become ever noisier. Everyone wanted to see the Jack Snipe but as it was virtually invisible it took lots of directions from anyone who was currently watching it to get new arrivals in the Hide to see it. Fair enough but the noise from all the chatter was incredible. Someone shouted to someone else from one end of the Hide to the other as if they were in the street. I sat and tried to phase out the annoyance of noise and disturbance.There was nothing else I could do.

With the Jack Snipe only just visible the Hide was full to bursting as everyone was waiting to see if it would move and they could get a better view of it but the Jack Snipe remained  asleep amongst the grass and reeds. Occasionally it would commence that curious bouncing movement they employ when feeding but this time remained rooted to the spot but still bobbing up and down and then it would stop and resume its slumbers. It looked like this was going to be an attritional wait of some hours.

There is however only so long one can look at parts of a persistently immobile Jack Snipe and remain interested so I diverted my attention to admire the other birdlife, mainly ducks, frequenting the marshy scrape.The light was truly awful for photography but still the splendid colours of the male ducks were irrepressible in the dull light.

Eurasian Wigeon, that most sociable of ducks were feeding very close to the Hide, on the grass bank that came right up to the Hide's wooden, plucking at the grass in small tight groups.

Eurasian Wigeon
The males are at their very best at this time of year, their heads a deep rich chestnut with a creamy yellow blaze on their forehead and a breast of the softest pastel pink.The females are much dowdier, brown and grizzled grey on their heads and bodies but the adult females show a plumbeous pink tone to otherwise brown flanks that the younger females lack.

Female Eurasian Wigeon
Eurasian Wigeon are a plump duck with a pleasingly curvaceous profile, their steep foreheads and rounded head imparting upon them a benign aura. Beyond the scrape on the large area of grassland and flashes of water called The Tack Piece hundreds more were also feeding, an animated carpet of grey, swarming in close formation across the wet grass.

Male Eurasian Wigeon

Many other birds were also out there, sharing the flat expanse of grassland. A huge flock of Lapwing rested there and periodically they and the wigeon would rise in alarm and circle in the sky, possibly troubled by the local Peregrine. As the alarm ceased the Lapwings would drift on the wind, slowly sinking lower, wheeling in a loose formation into the wind with reedy cries, to settle back on the ground along with the wigeon.

I looked through my scope, scanning across The Tack Piece and found other species such as Curlew, Ruff, Golden Plover and Dunlin. Beyond were a number of Bewick's Swans congregated by a long narrow ditch of water. They are very much an iconic species at Slimbridge and much work has been done on their ecology and it was good to see the numbers of this most appealing of swans

Other Bewick's Swans flighted in to join them, calling with soft bugling to those on the ground, their all white plumage still retaining a purity in the grey conditions as they flew with some grace to join the small flock out on The Tack Piece.

Bewick's Swans
I sat, quite happily in the Hide for a couple of hours watching the ever changing panorama before me,  revelling in such an abundance of bird life. 

Bewick's Swans
The wigeon were not the only ducks on the scrape as up to a dozen male Northern Pintails had arrived in the intervening hours to swim around on the shallow water and display amongst themselves and to the few females present. They are so very different in profile to the plump wigeon, their long necks and  pointed central tail feathers, accentuate their attentuated but elegant appearance. Like raffish dandys at an exclusive club  the males disport their finery amongst themselves finding it impossible not to pose and preen and constantly show off to the females, even when the latter are already paired to another.

Northern Pintails
Diminutive  Eurasian Teal drakes  swam across the water looking like tiny animated toys amongst the larger Mallard and Northern Pintail. A compact bundle of beauty they busied themselves like fussy waiters, swimming rapidly hither and thither for no obvious purpose or waddled on short black legs onto the land to preen and once satisfied, settled to reverse their green and and chestnut heads and tuck their bills into the back feathers to sleep.

Male Eurasian Teal
A couple of drake Northern Shovelers were syphoning the water through their outlandish bills. Such a  huge spatulate bill would make them seem grotesque were it not for the glory of their breeding plumage, a pallet splash of  bottle green, white and chestnut colour and gleaming yellow eye.

Northern Shoveler
A Lapwing came very close to the hide, close enough for me to see the patch of purple and midnight blue iridescence at the bend of its wing and the delicate buff fringes on the glossy green feathers of its upperparts. Its long wisp of a crest wavered, caught by the wind as it stood looking with large dark eyes for any movement of prey in the grass and wet earth it trod. A photographers dream, they move a few steps and then stand stock still surveying the ground before tilting down to seize a beetle or ant, or move another few steps onwards whether successful or not.

I found I was getting progressively colder in the Hide having sat for three hours with a cold wind now blowing relentlessly through the viewing slats. Visitors came and went as the constant disturbance began to get to me. Apart from slightly changing its position the Jack Snipe showed no inclination of feeding and consequently coming out of its current concealment. I decided to try another Hide, Willow Hide, as the walk would get my circulation moving once more. I was delighted to discover a Water Rail below the feeders in front of the Hide, taking the opportunity of picking up fallen seed from the feeders, just as the Water Rails do at my local Farmoor  Reservoir in neighbouring Oxfordshire. 

Water Rail and Eurasian Teal
It was joined by a few teal who also saw an opportunity to snaffle up the seed. Water Rails are inveterate skulkers, nervy and highly strung but this one seemed to have overcome its innate shyness for the most part but eventually it sought the cover of some adjacent brushwood and stood quietly before  edgily re-emerging but the sudden arrival of a  Jackdaw was too much to bear and it was gone in a flash with feathers flattened and tail flicking, anxiously running deep into cover.

I returned to the Martin Smith Hide to find in my absence that the Jack Snipe had moved, just as I hoped it would,  but perversely not to a more open situation but exactly the opposite  and it was now virtually invisible but one brave gent with a telescope was desperately trying to assist members of the public to see whatever miniscule part of the Jack Snipe remained visible. Each time he repeated the words ' If you look in my scope, you should see a reed that is bent over. Look at the top of that and just beyond and you can see its eye!'

This was repeated ad nauseam as a succession of people not unreasonably failed to see the Jack Snipe through his scope. He meant well but it inevitably became  tedious and annoying as he repeated his mantra over and over to each new visitor to the Hide.

He was finally silenced as the Jack Snipe moved. It was approaching 2pm. The Jack Snipe, disturbed by a Moorhen commenced its curious bouncing up and down on flexed legs which is often but not invariably a sign that it intends to start feeding. Incidentally the reason it bobs like a small toy is so its monocular vision can act in binocular fashion allowing it to judge distances and depth of field

It was at the back of the grassy scrape but slowly commenced working its way forward along the muddy margin of the scrape but was forever and frustratingly obscured by blades of grass or spikes of sedge and reed. There  were just a couple of tiny areas of open mud without any vegetation right opposite my position in the Hide  and I  willed the Jack Snipe to progress as far as them. Slowly it 'pogo'd' its way towards the front edge of the scrape. I held my breath but it diverted off into the grass. I gave an involuntary sigh of disappointment but to my relief it came back to the water's edge and at last showed itself, almost perfectly as it gently undulated along, probing its bill into the soft mud as it progressed around the scrape's margin.

Jack Snipe
I was in a transport of delight as I absorbed the details of its cryptic plumage. Most striking of all were the two long lines running down each side of its mantle, which in this light looked very bright, almost pale orange or a very rich buff. They were really that striking. It moved onwards showing no alarm at the close proximity of a Mallard which towered above it but when a Moorhen came close it ran in a crouched panic and was gone from view as it retreated to the back of the scrape.

Drake Mallard and no Jack Snipe

 Drake Mallard and Jack Snipe!
It had been a long wait to see the Jack Snipe properly but ultimately rewarding and well worth enduring both the mental and physical hardships but now it was most definitely time to go.

Thursday, 10 January 2019

A Great Northern Diver on the River Thames 9th January 2019

Today I drove from my home in the extreme northwest of Oxfordshire the length of the county to Beale Park which lies by the River Thames just in Berkshire, the river hereabouts forming the county line between Berkshire and  Oxfordshire.

It took about an hour to drive to Beale Park and my reason for going was to see a juvenile Great Northern Diver that was first found on a lake adjacent to the river but latterly has taken  an apparent preference for the river and is to be found anywhere along an approximate mile stretch of the river either side of Beale Park and is easily viewable from the grass towpath that runs beside the river.

In pleasant sunshine but chastened by a raw and cold wind I left the car in a deserted and closed Beale Park at just after twelve noon, and made my way along a muddy track, past the lake to the flat grassy towpath. In direct contrast the opposite bank of the river, in Oxfordshire, rose steeply, a thickly wooded slope ascending to the skyline.

River Thames dividing Berkshire from Oxfordshire
The river at this time of year is relatively undisturbed compared to the plethora of craft that take to it in the summer months and similarly the towpath was free of much disturbance. I encountered just a couple of local birders and a dog walker during my two hour visit. This probably encouraged the diver to frequent the river where the fishing was possibly better. 

On reaching the river bank I was very fortunate to immediately come across the diver swimming in the middle of the river, diving for food and due to its location, currently in Berkshire. I followed it, as by means of a series of leisurely dives, and exhibiting some interesting behaviour, it slowly moved downriver, in the direction of the town of Pangbourne and deeper into Berkshire.

Maybe a touch of indigestion?

Note how low in the water it can sink its body.The water is literally washing
over its body behind its neck

'Snorkelling' where it swam along on the surface looking below
the water for any likely fish to catch
Two scullers also coming down river caused it to dive and double back underwater and I then found myself following the diver up river until we were in Oxfordshire! The diver was relatively unconcerned about my presence and continued steadily fishing whilst moving further upriver. Each time it was underwater I tried to move along the towpath to a spot where I anticipated it would surface. Sometimes I got it right and at other times not so but generally myself and the diver remained in reasonably close contact.

The diver continued feeding for the entire two hours I observed it  and on two occasions I saw, what was for me, a unique event. I have watched  countless Great Northern's diving and fishing and they always seem to consume their prey underwater before surfacing but twice this diver brought a large fish to the surface in order to deal with it and swallow it. The first fish was a Tench, judging by the fins and the diver took some time to manouevre it into its bill to swallow head first.The second fish was a Pike which looked a little on the large size but this I believe went down the same way as the Tench

The above two images are of the diver swallowing a Tench

Here the diver has caught a Pike.
For the next couple of hours I discreetly followed the diver along the river, concealing my outline by utilising the clumps of bramble and small trees growing on the bank to disguise my presence to a degree, although the diver knew I was there.

A spot of feather maintenance. Note the length of its body

Preening and showing the intricate scaly patterning of juvenile feathers on its
mantle and wing coverts

Watching a small aircraft passing over
Great Northern Divers are comparatively rare inland and especially so on rivers, preferring to remain on the sea around our coast. or if they do come inland usually finding large reservoirs or open bodies of water more to their liking. Undoubtedly the nearby lake had originally attracted it as it flew along the Thames Valley. It is thought that most Great Northern's that occur around our coast and inland originate from Iceland.

I watched this large bird, its size making its movements when resting on the water's surface almost ponderous although it is supremely adapted to a virtually exclusive aquatic existence. It has a formidable sized bill that is long, dagger shaped and at this time of year pale grey, requiring a large head and powerful neck to support it. The forehead has a curious ridge of feathers that is very distinctive and looks like a large bump when seen sideways on. 

Its long flat torpedo shaped body can be held low in the water, so low that water sometimes flows over its back where it joins the neck and the diver and water become almost as one. The legs and feet are placed very far back, almost at the end of its body to give it the power to propel itself  rapidly as it hunts its prey underwater.

This bird is a juvenile, as are most that are found inland, told by the prominent scaling all over the upperparts of its body, each feather immaculate and precisely aligned with its neighbour and its eyes, prominent in a pale face  shone ruby red in the bright sunshine. It will be two years before it reaches maturity and commences to breed. 

Inevitably while wandering along the riverbank I came across other waterbirds. Four very wary Mandarin Ducks, two males and two females, and up to now hidden in an overhanging mess of twigs and branches on the far bank that swept down into the cold dark green waters of the river, briefly and unexpectedly emerged from concealment. As still as a statue a Grey Heron stood on the far bank and black, sinister looking Cormorants, craning their sinuous necks in anxiety at my presence, perched on the skeleton of a dead tree, fallen haphazardly across the bank and partially into the water, while Little Grebes swam furtively into quiet backwaters, hoping not to be noticed.

There were many alder trees growing in wetter parts of the hinterland between the towpath and the lake, their twiggy upper branches thick with plump catkins still maintaining a solid and firm unopened compactness, but it will not be long before they burst and these had attracted half a dozen Siskins, the males already commencing to sing. A couple of Lesser Redpolls were an unexpected  find, rising up into the sky with their distinctive calls from a birch tree.