Updates from our Cuckoos

BB has become the first of our Scottish Cuckoos to leave Britain. On the 16 June he was still in Flanders Moss NNR (between Aberfoyle and Stirling), where he and three of his colleagues had moved from the tagging location. During the morning and early afternoon of Monday 18 June, however, a series of locations tracked his progress as he moved SE over the North Sea to the Friesland Islands in the Netherlands. This is the first time we have tracked or seen such a long a sea crossing by the Cuckoos – there is no indication that he attempted to minimise the distance he flew over the sea, as we have seen some of the Cuckoos appear to do last year over the Mediterranean. It’s not possible to say for sure where he started his sea crossing but it was probably somewhere between Edinburgh and Berwick-on-Tweed - this would make the crossing about 550-600km (342-372 miles) long.

Indy has followed the other three Welsh male Cuckoos out of the country. New locations received on the morning of 20 June showed he has moved approximately 275km (170 miles) SE from his previous position in Surrey and was now in the Picardie region of France.

Following in the footsteps of the other three male Cuckoos tagged in Wales, Indy has made a huge leap east in recent days. As late as Friday evening (15 June) we received data from his tag to show him north of Tregaron in Wales. This morning (18 June) we received data from Indy's tag in Surrey, half way between Farnborough and Woking, having travelled 245km (153 miles) ESE over the weekend. This means that all of the Welsh males have made an initial movement east from the tagging area - it will be interesting to see if this continues or whether any turn south and take the westerly route in Africa used by Clement and Martin last year.

David has followed the example set by our other Welsh male Cuckoos and made a move East. Like Iolo, he has taken a more northerly route and arrived in Norfolk.

We received data from his satellite tag on Monday 11 June that showed he was still in the area where he was tagged on the 30 May 2012 near Tregaron in Wales. We next heard from David's tag on the morning of Saturday 16 June, when we received a number of transmissions that gave a location near North Walsham in Norfolk. That's a distance of 360km (225 miles) travelled just north of due east between transmission locations.

Iolo was the first of our Welsh Cuckoos to make a move east, having arrived near Mildenhall, only 20km (12 miles) from BTO HQ, on 7 June - a week after he was tagged near Tregaron! By11 June he had moved 40km (25 miles) north to a location near to Tottenhill, 10km south of King's Lynn. The last transmissions received from Iolo's tag on 16 June indicated that he was still in that area.

Our nameless Welsh Cuckoo was the second to leave Wales, following Iolo. On the evening of the Tuesday 12 June we received data from tag 115597 showing our Cuckoo to still be in the area where he was tagged, near Tregaron. By the evening of the next day (13 June) Cuckoo 115597 had moved approximately 160km (100 miles) SE, having crossed the border into England, and was in Wiltshire, 5km north of Devizes.

Transmissions received unexpectedly on the 14 (his tag was not due to have transmitted until the following day - its duty cycle may have been reset by perching on electric cables or exposure to a similar magnetic charge) showed that he had moved a further 160km (100 miles) in an easterly direction and was 8km (5m) north of Sevenoaks in Kent. That's a total distance of 310km (195 miles) covered in two days. Further data received on Saturday 16 June show that he remains in this area of Kent.

With no further transmission from Kasper's tag we have had to accept that his journey has come to an end.