Updates from our Cuckoos

The charge on both Chance and Tor’s tags was very low on the last transmission before they went 'missing’. We hope that like Tor’s, Chance’s tag will resume transmissions once it has been exposed to sunlight after he moves to a new location. If it does not, it is most likely that the battery completely discharged during the period that it was not charging sufficiently to transmit and subsequently perished. In previous years, the tracked cuckoos have mostly died during the main spring and autumn migrations between Europe and Africa, rather than during the mid-winter period, so battery failure would seem more likely than Chance dying during the period that his tag was uncharged.

We still have yet to hear news from either Chance or Tor, who had been in a similar area of dense cover close to the Gabon/Congo border, when their tags last transmitted. 

If their respective batteries have not been receiving enough solar charge to power them over a long period of time there is a possibility that the battery may degrade and not be able to power up again. However, if they have been receiving some small charge during this time, though not enough to send a transmission, then once exposed to enough light, transmissions should start back up again. We continue to hope that like David, who went over 6 weeks without a tag transmission but recently re-emerged, Chance and Tor may reappear if and when they move northwards. 

Still no news from Chance. However, despite not hearing from him since early December we haven’t given up on him. The last transmission showed that the tag temperature was as expected if he was alive; however, the battery charge was extremely low, so low that the tag must have stopped transmitting immediately afterwards. 

The latest transmissions from Ken's tag show that he remains in Gabon, having arrived here on 25 October, and it's likely he will spend Christmas here.

This is also the last country from which we received a transmission from Scottish Cuckoo, Chance, in early December.  We haven't heard from him since but, there could be a number of reasons for this, including the fact that the dense cover of vegetation could be stopping the solar-powered tag from receiving enough light to charge up and transmit a signal.

Interestingly, Tor, one of our Devon Cuckoos also last transmitted from this area at the end of November, although from slightly further south within Congo, and his tag has also yet to beam another signal to us. Many of our Cuckoos have had periods where they have 'dissapeared' for a period of time before reappearing, often having moved quite substantial distances as part of their migration, having spent time feeding up beforehand. We will have to wait and see whether further transmissions reveal more information.  

Chance has moved roughly 150 km (95 miles) south-west from his first location in Gabon, away from the Teke Plateau area and is now to the west of this. Recent movements from other Cuckoos arriving in this area suggest that conditions may not be so good in the area this year as in previous years and this may explain Skinner's southerly movement to Angola.

Over the weekend, Chance has moved south from Nigeria to Gabon, covering a total of about 1320km (820 miles), as he crossed over Cameroon and ventured further south-east. Signals late last night and early this morning show he is now in the Haut-Ogooue region of east Gabon and is now in the Congo Rainforest, where he will spend the winter. 

Two of our Scottish-tagged Cuckoos, BB and Chance, from 2012 are currently in the most northerly locations of those we are following this year. BB remains in Chad, while Chance is still in Nigeria.

Chance did make a move south, almost reaching Nigeria's border with Cameroon, but for some reason retreated in a north-westerly direction again. He is currently just south of Gombe. By mid-October last year, he was further south, in Cameroon, but didn't move again until the beginning of November, when he journeyed to the Téké Plateau – the area of savanna and gallery forest in central Congo.. Will we see him do the same again in the next couple of weeks?  

As for BB, last winter he spent from 17 September to 4 December in the same area as his current locaion in Chad, before then moving south to theTéké Plateau. If he does the same again this year, it may be a while before we see any further movements.

In addition to BB and Chance, this wintering area was also used by four of the Cuckoos tagged in East Anglia in the first year of the project , who spent winter of 2011/12 in the Téké Plateau, with the exception being Chris who each year has wintered in the Likouala-aux-herbes area, where he is currently. Last year, our English Cuckoos fared badly on their southward migration and Chris was the only East Anglian Cuckoo to make it to his wintering grounds. It will be interesting to see how many move south to winter in the Téké Plateau this year.

From the shores of Lake Chad on 2 October, Chance moved south-west and by 7 October was 330km (200 miles) from the lake. He is 90km (55 miles) from the city of Maiduguri which is the capital and the largest city of Borno State in north-eastern Nigeria. 

By the early hours of 10 September Chance had travelled the final 70km (45 miles) or so and was on the shores of Lake Chad. About 80km (50 miles) separate him and fellow Scottish-tagged Cuckoo, Patch, who is on the other side of the lake.