TRANSLOCATION - THE PRE-RELEASE STAGE

On arrival at Rutland Water, the Osprey chicks were placed in release pens, built by Reserve volunteers. 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.

Volunteers erecting the release pens. Below is the caravan from which the birds are monitored.

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. A litter-picker was used to remove any uneaten scraps so as to reduce the risk of infection. Scrupulous hygiene rules were enforced around the pen.

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. For example, they could be seen watching Wood Pigeons flying over the pens, calling in response to one another and reacting to the distant sight of people and fishing boats on the reservoir. At this stage monitors 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 - bird 01, 02 etc.

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 stage, when feeding took place, the birds reacted aggressively towards the hand that came through the hatch. Frequently this behaviour suddenly reduced - an indication that the birds were ready to fly.

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 .