Updates from our Cuckoos

Chris, BB and Lloyd have still yet to begin their northwards movements and have all transmitted, from the same positions, in the last few days. Given the pattern seen so far, we may expect to lose transmissions for a few days as they feed up before they then make their move north. 

There have been no further transmissions from David since the 2 February, just after his big move, however the tag charge was low then. Hopefully it may receive some sunlight soon and charge up enough to transmit his current location. Chance is about 270km (168 miles) away from David's last known location. 

BB's tag transmitted on the 29 January while Chance's tag sent locations in the early hours of this morning which show that they remain just a few miles apart - possibly as few as two miles.

Further signals in the last couple of days reveal that BB and Chance are now only 4km (2.5 miles) apart from each other – that’s closer than when they were first tagged at either end of Loch Katrine in The Trosssachs National Park in Scotland! From transmissions received yesterday, BB appears to have travelled 2km (just over a mile) to the west, while transmissions today show Chance has moved 2km north and then 1km east of his previous location.  They are so close now that you have to really zoom in on the map to be able to see both markers.

 A transmission on the evening of 10 January confirmed BB’s location as still being close to the river. A transmission in the early hours of 13 January showed he had moved 119 km (74 miles) almost directly north. He is now in the Cuvette-Ouest region. Chance is about 7.5km (5 miles) from this new position, his tag transmitting from this location a matter of hours after BB did so. Chance and BB have moved to the first block of continuous forest to the north of the grassland - gallery forest mosaics of the Teke Plateau and are now only 100km (62 miles) from Chris to their north-east.

There have been some small sighs of relief as BB’s tag starting transmitting again yesterday, after a silence of 11 days, confirming that all was ok. He had probably emerged from dense cover where the tag had not able to charge or transmit. The transmissions at around 10pm show that his new location is about 30km (19 miles) north-east from the previous location, and that he has remained roughly 8km west of the winding river. It is good to be receiving signals from him again! 

So far in 2013, we have heard from four of the five remaining Cuckoos. We received tag transmissions from Chris and Chance today and from Lloyd and David yesterday showing there had been no substantial movements to report.

However, we haven’t heard from BB since the 30 December - at this stage this is nothing to worry about, though, as at this time last year we regularly went longer than this without hearing from the Cuckoos. A combination of poor charging conditions and a gradual decline in battery charge mean that they are transmitting less often, whilst as they are within the forest interference from trees reduces the chances of transmissions being picked up by satellites. Once they move on, or the weather at their current locations improves, we should start to receive positions more regularly again. 

Transmissions were last received from BB's tag on the 30 December and show that he is still in the same area.

BB's tag transmitted in the afternoon on Christmas day. His position within Congo remains unchanged. Chance, the only other remaining Scottish-tagged Cuckoo, is the closest to his position, around 100 km (60 miles) to the southwest.

Now that BB has moved south, the five Cuckoos that we are still tracking all appear to be at, or close to, their final wintering locations. Although we can’t draw firm conclusions from such small numbers, the Scottish-tagged Cuckoos are wintering in the same area as the Cuckoos tagged in England (bar Chris) did last winter. The two Welsh Cuckoos are further to the east. This is really interesting but whether it reflects general differences in the wintering areas used by the different breeding populations will need to be confirmed by the results of further tracking work in the coming years.