Wednesday 20 September 2017

An Oxford Osprey 17th September 2017

I left my house in the dark at 5am on a Sunday morning for a rendezvous with an Osprey. I had been asked to keep the location secret so as not to attract too many visitors and potential disturbance to this coveted migrant raptor. I also had to be there by dawn as the show only lasted for the first two hours after dawn. It would all be over by 9am at the latest.

One hour later I arrived at my destination and drove down a narrow track between some small lakes and parked off the track  below some trees. The sky was just turning a pale shade of grey as the dawn reluctantly rose on a wet and dank landscape, the trees still dripping from a night of light rain and the ground underfoot wet, muddy and with the first leaves of autumn already fallen.

I walked along the rutted track, slip slided on the wet mud and around deep puddles, then up and over an earth mound to descend the other side to a small reed fringed lake guarded by large trees on three sides. I stood by the still waters of the lake as slowly, ever so slowly the growing light revealed the far bank of the lake and the trees became defined in both shape and detail rather than just amorphous dark lumps silhouetted in the half light.

It was still, not a breath of wind troubled the leaves of the trees or waters of the lake. Now light enough to see every detail of the landscape around me. I could see the inverted images of the reeds and trees perfectly reflected in the mirror surface of the lake. It was absolutely quiet, a Sunday quiet. The air was damp with moisture. A Muntjac barked nearby, a sudden staccato sound, its loudness accentuated by the still air. Its unexpectedness  startled me until I realised what it was.

I had been told that if I waited by the shallow waters of the lake I could be assured that an Osprey would come to fish here, as it had been doing for almost two weeks now. It was a young bird, raised this year, maybe in Scotland and was now making its first long journey to southern Africa where it would remain for the whole of next year, not returning to breed until its third year. Multiple hazards faced it before it could make the return journey and it would be a tough existence but then only the strongest survive to breed and pass on their genes. Nature does not indulge in sentiment.

At just before 6.30 the reason to keep company with the dawn  arrived, sweeping in from behind me and not that high, flying around the lake to land near the top of a large Ash tree overlooking one end of the small lake. In the sky, with minimal light to define its plumage it was just a large dark, long winged raptor but on landing in the tree I could see its white underparts as a distinct white slash of colour against the pervading green of the Ash leaves. I trained my telescope on it and the whole bird came to life in the scope's magnification as its structure and feathering was clearly revealed.

Ospreys are magnificent. Large birds of prey with a combination of white underparts and dark brown upperparts, a white head and bands of black encasing their eyes of fierce yellow, that stare out on the world, whilst white feathered legs and black talons are the tools with which it ekes out its living, catching fish. They are spectacular in both appearance and behaviour and as they eat live fish they have to indulge in dramatic dives into water to seize an unsuspecting fish swimming near the surface. The dives are not subtle but entail either  hovering and circling over water or a glide from a vantage point, in both cases leading to a violent collision with the water, legs and feet extended out in front, creating a huge splash as the bird literally crash lands on the water and often is briefly totally submerged before the huge wings lift it and its prey from the water. Not all their dives are successful and certainly young birds more often miss their target and return to the air with empty talons. But they are nothing if not persistent and will continue to survey their chosen stretch of water for a victim until they are eventually successful.

Ospreys have a cosmopolitan distribution being found on all Continents apart from Antarctica and, after the Peregrine are the most widely distributed raptor in the world with a population estimated at 460,000 individuals. Some populations are migratory such as those in Britain whilst others are sedentary such as in Australia.

Historically, mainly due to Victorian egg collecting and hunting, Ospreys were extinct in Ireland by 1800 and England by 1842. In Scotland they survived longer until 1916 but then no more were seen until 1954 when Scandinavian birds re-colonised Scotland naturally and a pair have been breeding annually since 1959 at the RSPB's famous reserve at Loch Garten  and despite the desperate attempts of egg collectors, including trying to saw down the nesting tree in the 1960's, have remained an iconic and popular tourist attraction to this day, being visited by over 2 million visitors since 1959. The 1950's and 1960's saw another threat to the Ospreys in the form of organochlorine pesticides but once these were banned in the 1970's and nests were protected round the clock from egg collectors the population slowly increased, so that by 1991 the number of pairs had increased to 71 and in 2011 the RSPB estimated that there were between 250-300 pairs nesting in Britain. Since 1999 they re-commenced breeding in England in the Lake District and famously at Rutland Water in The Midlands. They have, since 2011, also commenced re-colonising Wales.

This rising population of Ospreys has significantly increased the chances of anyone encountering this beautiful and spectacular bird on any reasonable sized expanse of water as they migrate to and from Africa. On our own Farmoor Reservoir in Oxfordshire they are a regular passage migrant in both Spring and Autumn, stopping off to help themselves to a meal of trout. Thames Water have even erected two nesting platforms at the reservoir, similar to those at Rutland Water, in the hope of enticing them to eventually breed. Occasionally, such as at Blenheim Lake and at Radley this year, they turn up at other locations much to local birders delight and it is always a significant event to see one as they pass through the County.

The Osprey I was looking at in my scope could be identified as a juvenile by the fact the brown feather coverts on its upper wings had each feather tipped with orange buff so  each feather tip joined to create a 'string of pearls' effect of orange buff lines across the wings.The barring on its tail was another indication it was a juvenile.

The Osprey sat in a tree whilst its glaring yellow eyes surveyed the lake. Its head and neck shimmied in a snake like dance as it adjusted its line of sight. I of course could see nothing in the lake but the Osprey's sight, infinitely superior to mine, missed nothing.

Fifteen minutes passed and it launched its first sortie down onto the lake, dropping in a long glide and then levelling out with white feathered legs and black talons lowered to grab the targetted fish. It hit the water with some force, creating a whirl of disturbed water, spray and sound on the lake's previously untroubled surface and briefly held itself afloat with horizontal wings before rising, unsuccessful in its attack, to fly back to its favourite perch. 

Two Grey Herons arrived, their heads sunk into their convoluted neck, with stick thin legs projecting behind their tails, their compressed, gaunt bodies held aloft on broad grey wings, looking preposterous. Locals, not used to this transient interloper on their secluded fishing grounds  they were disturbed by the Osprey's presence and one set about letting the Osprey know, flying up to it and mildly threatening it with extended neck and formidable bill. The Osprey responded with open beak and wings held half spread. The Heron, its bluff called, thought better of it and with a loud explosive squawk of exasperation and defiance departed for quieter fishing.

Thrice more the Osprey attempted to snatch a fish from the water and each time the ensuing splash and spray of its violent immersion failed to be successful. On its last sortie it returned to its perch as before but then maybe recognised that this was not to be its morning here and  moved on towards the nearby Thames.

It was over and the Osprey, from all previous reports was unlikely to return. Maybe it would tomorrow. I left the lake to a pair of Mute Swans, floating once more on a lake that was serene and still.

It was as if nothing had happened in the last two hours.