Historically the Osprey was widely distributed throughout England, particularly those areas like the fens which would have provided ideal feeding and breeding habitat. However, intensive persecution by man (egg-collecting and taxidermy) during the last century, combined with prime habitat loss, led to its extinction as a breeding species in England in the 1840s. The last breeding record was in Somerset in 1847. Ospreys retained a tenuous hold in Scotland in remote areas until the last recorded breeding in 1916.
In 1954 a pioneering pair of Ospreys attempted to breed at Loch Garten in the eastern highlands of Scotland. With vigilant protection and a change in attitudes towards birds of prey, the Scottish population has grown slowly to over 210 pairs.
However, natural colonisation was slow, as young male Ospreys prefer to breed close to the sites where they first fledge. This behaviour led to the formation of loose nesting colonies with pairs competing for nest sites – up to five birds have been known to compete for a vacant site. Over 50 years since the first Scottish breeding success, the majority of nests are still close to the original site. The population in Scotland, while currently expanding in size, does remain vulnerable to food shortages, disease and the vagaries of the weather. Bearing all this in mind it was estimated that it could take at least 150 years for Ospreys to naturally re-colonise the whole of the UK.
Ospreys at Rutland Water
The reservoir at Rutland Water was constructed 30 years ago and has become an internationally important sanctuary for wintering wildfowl. It is now a SSSI , SPA and Ramsar site. From early in the reserve’s history, Ospreys had been observed using the reservoir as a convenient stopping-off point during the migration. Colour rings had been seen indicating that these migrants come from the Scottish population as well as occasional sightings of Swedish birds. In 1986, the first efforts were made to attract passing migrants to breed, with the erection of an artificial nest in the top of a tree on Lax Hill, a high point on a promontory overlooking the reservoir.
In 1994 a young female remained at the Reserve throughout the summer but she did not re-appear the following year. Also In 1994 a number of artificial nesting platforms were constructed under the guidance of Roy Dennis of the Highland Foundation for Wildlife. Roy is a world authority on Ospreys and other raptors and together with Reserve Manager, Tim Appleton, he began to form the idea of translocating Scottish Ospreys to Rutland Water. The project quickly received the backing of the Leicestershire and Rutland Wildlife Trust who manage the Reserve. Crucially, Anglian Water who own the reserve, pledged financial support, allowing long-term plans to be drawn up.
Before licences could be granted, it was necessary to consult with national and local organisations on the impact the project might have on landowners, fish farms, fishing clubs and conservation societies. There are international criteria concerning the translocation of species which had to be satisfied. In addition, an independent population analysis was carried out to ensure that the Scottish Osprey population was sufficiently stable to allow removal of young without significant impact. A steering group was set up and a detailed proposal submitted to the licensing bodies. In May 1996, members of the project team visited the Raptor Centre based in Minneapolis, Minnesota. There Ospreys breed in close proximity to man.At the Raptor Centre successful experience of translocating Ospreys has been built up over a period of 20 years and we learned much from that experience.
In June 1996, following 18 months of negotiation, a licence was granted by Scottish Natural Heritage under section 16 of the Wildlife and Countryside Act(1981), allowing up to twelve chicks to be removed from a choice of 35 nests in the eastern Highland region of Scotland. This licence had to be renewed every year of the project’s duration. The approval of English Nature was also sought in order to hold young birds in temporary captivity at the reserve.
First Translocations
Birds for the translocation project were collected from Scotland. The Scottish birds are presumed to be closest genetically to the original English population and the journey from Scotland would much less traumatic for the birds than being translocated from Osprey populations in Europe.
Each year many Osprey nests in Scotland are monitored from the time the adults return in the spring. This work is carried out by a dedicated independent monitoring team co-ordinated by Roy Dennis. This close monitoring identified nests that would be suitable to provide chicks for translocation.
During the translocation phase of the project, 6-week-old chicks were chosen from broods of three or sometimes two, in accordance with the licence requirements. These chicks were placed carefully in cardboard boxes and, overnight, driven down to England. All donor nests were on private estates or on Forestry Commission land. The chicks were given two rings, as are all Rutland osprey chicks, a colured darvic ring to help with idenitfication and a BTO ring.
On arrival at Rutland Water, the Osprey chicks were placed in release pens. The pens were sited in an elevated position so as to provide wide-ranging views over the lagoons of the Reserve and the wider body of the reservoir. The pens were approximately 2m square and each one contained an artificial nest resembling a natural eyrie, together with perches. Three chicks were placed in each pen, mirroring the nest situation in the wild.
The chicks were fed twice or three times per day with pieces of fresh trout provided by a local fish farm. There were small hatches through which the food could be introduced and the backs of the pens were solid so that there was little disturbance to the birds at feeding time.
During the first phase of translocation the birds’ behaviour was closely scrutinised by a team of volunteers, working in shifts in a nearby caravan and using a closed-circuit TV system. Notes were made of each bird’s movements, their wing flaps were counted and the time spent feeding noted. Initially the birds spent a large amount of time lying prone on the artificial nest but as time went by they became more active and began to take an interest in their environment. At this stage volunteers began to note different characteristics of the birds. Some were more dominant, while others assume a very submissive position within the nests. Although the monitors began to recognise individual birds, they did not give them names other than the numbers marked on their plastic rings.
During this period the birds receivd a general health check from vet Sue Thornton, a raptor specialist from London Zoo. Weights, state of plumage and general development were recorded and a blood sample taken for analysis. DNA testing of the blood samples by specialist company, University Diagnostics Ltd, subsequently enabled us to tell the sex of each bird. Regular faecal samples were also collected from the pens and sent for analysis.
As the birds matured they began to spread their wings and allow the wind to lift them gently off their perches. Short distance flights then took place across the pen and louder, more insistent calling was heard.
At this point each bird had a small radio tag attached to its central tail feather. These tags weigh 15g and have been specially developed for use with raptors. The radio tag was attached to a plastic tube which slides down over the shaft of the feather as far as its base. The radio’s aerial was then attached to the length of the shaft using dental floss and glue – a very delicate operation. Finally the feather’s barbs were straightened and any excess cut from the end of the aerial. The purpose of these radios was to allow the project team to keep track of the young birds as they made their initial flights around Rutland Water. The tiny batteries in the radio tag last for up to eight months and the signals could be picked up over a range of several kilometres. Each bird’s radio transmitted signals at a different frequency, allowing individual birds to be located. The radio tag and aerial remained on the bird until it moulted its tail feathers after about one year .
When the birds in a particular pen were ready to be released, volunteers were posted discreetly at key vantage points around the Reserve and the front of the pen was gently lowered. Often it was several hours before the birds launched themselves from their platforms although some birds took advantage of their freedom immediately. It was always a tense moment for the project team who still found it hard to believe that the birds would be able to fly. But fly they could – instinctively knowing how to use their wings to gain height, how to glide, how to change direction in the air. The first flight often lasted for 3 or 4 minutes and often terminated when the bird, rather inexpertly, landed in a tree or on one of the nearby artificial nests or perches.
Once the birds were flying freely, the task of the volunteer monitors changed dramatically. Rather than viewing the caged birds on TV screens, the monitors now used binoculars and telescopes to try to keep track of the young Ospreys. There were three monitoring stations from which most of the reserve could be viewed and the team were able to communicate with each other using short wave radios. One person was responsible for recording the locations and movements of the birds as they began to explore their surroundings. It was now that radio tracking of the birds began, using a strange looking piece of equipment known as a yagi. By moving the large aerial around and twiddling the knobs to receive different frequencies, it was possible to identify particular birds even if their ring numbers were not visible.
Fish, now cut into larger pieces or left whole, continued to be provided on the platforms near the release pens. Until they migrated the young Osprey came back to feed on this fish, just as their siblings in Scotland returned to their nests to take fish that continued to be provided by their parents.
There were one or two occasions when young birds ran into trouble during their early flights and it is then that the need for efficient monitoring became obvious. One year a young bird was seen to dangle its legs into the water in one of the lagoons, presumably tentatively looking for fish. Unfortunately its talons became entangled in weed and it was unable to rise out of the water. Had it not been for efficient monitoring, the bird would probably have drowned, but the project team were able to reach it without delay. Another story which has become legendary at Rutland Water, concerns bird 05 in 1998. Soon after its maiden flight and on a day when there was a strong south-westerly gale and squally showers, 05 was seen flying low over the reservoir to the north east and apparently unable to make headway against the wind. Osprey volunteers have all manner of ‘day-jobs’ and that day local vicar Michael Rogers was part of the monitoring team. Monitors alerted the Project Officer to the plight of bird 05 and Helen Dixon and Kate Aspinall headed off in a vehicle towards the village of Hambleton fearing the worst. Michael’s parting words to them were , “Don’t worry – I’ll pray for its safe return.” On their arrival at Hambleton the team were able to pick up a strong radio signal from 05, coming not as they had feared from the water but from the village itself. At first they could not locate the bird at all, but suddenly they realised where it was – sitting on top of the spire of Hambleton Church, looking for all the world like a weather cock! The story did not end there because later, 05 moved to the roof of Hambleton Hall, the exclusive hotel and restaurant. Helen and Kate, wet and dirty in wellies, plucked up courage to approach the reception desk and ask permission to watch the bird from the grounds. The bird found Hambleton Hall much to its liking and stayed on the roof for about 18 hours before deciding that the food, after all, was better on the Nature Reserve!
By the end of August or early September the young Osprey were often spending long periods of time away from the Reserve and out of range of the yagi. They were seen at various other lakes and rivers in the vicinity and usually returned each night to feed. Then, often on a bright clear breezy day, radio contact was lost with individual birds and they did not come back. On occasions this start of migration was witnessed by volunteer monitors and members of the project team: a bird would set out with determined purpose towards the south, flying strongly and gaining height as it became a speck in the sky and then nothing. The birds did not all leave together, although some days, when the weather was right, two or three birds left at the same time.
Further Translocation in 2005
During the 2004 season, 6 non-breeding adult males, were frequently recorded in Rutland, as well as the regular breeding pair. All eight adults were birds that had previously been translocated. Based on the previous experience of translocation in North America, it had been expected that these males would have been able to attract passing females to stay and breed, but this was proving not to be the case. Indeed the two breeding females in 2003 were females that had themselves been translocated.
Following detailed discussion, early in 2005 a detailed proposal was made to Scottish Natural Heritage and English Nature. We requested permission to collect a further batch of young Ospreys from Scottish nests during 2005, but this time trying to select females rather than males.
The success of the Rutland Water translocation project has led directly to similar osprey translocation projects starting in Andalucia in Spain and Maremma National Park in Italy.
Eventually, in June 2005, permission was granted to bring chicks from Scotland to England in order to redress the gender imbalance in the Rutland population. Eleven chicks were moved south and nine of these turned out to be females. One disappeared very soon after its release but the other ten migrated in September.
Future Translocations?
There are currently no plans for any future translocations to Rutland Water. The long-term aim of the project is to create a completely self-sustaining breeding population and we are confident that we now have sufficient adult ospreys and returning chicks to form a population that does not need to be supported by translocation. It is encouraging that the population is being swelled by Scottish Ospreys who are now stopping off to breed as we had first hoped.
