Updates from our Cuckoos

In the last few days we have been receiving signals from Tor's tag - surprising us as we last heard from him just north of the Congo Rainforest in March! These new signals show he made it to Morocco but unfortunately it does look like, despite successfully completing the crossing of the Sahara desert, he has since died there. This shows that tag failure was responsible for his initial silences but unfortunately it looks like the desert crossing was too much for him and he didn't have the reserves to continue onwards. 

Tor has once again gone silent. The last signal received was on 12 March, just after he moved north to Central African Republic. Before that there was a silence of 3 months. It could be that the tag is not transmitting properly so we will have to wait and see whether he receive any further locations in the future. 

We’re delighted to write this blog today as, after a silence of almost 3 months, Tor’s tag has sent new transmissions. The signals, received on 3 March, are the first since the beginning of December and reveal that he is now in the Central African Republic. Perhaps there is still hope that Chance may reappear too?

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. 

We still haven’t heard from Tor since his tag transmitted on 4 December. As that signal carried no diagnostic data we were unable to check his body temperature or the state of the tag’s battery. 

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.  

We are still following two of the four Cuckoos tagged in Dartmoor earlier this spring. Tor is in Congo, west of the Téké Plateau and Whortle is in the closed canopy forest in DRC, between Lac Mai and Lac Mumba and is midway between Patch and Waller.

The other two Cuckoos tagged there both perished in August, Ryder struggled to cross the desert once he arrived in Africa, while Dart made it to Mallorca but wa likely affecfed by dry conditions and wildfires there.

We hadn't received transmissions from Tor's tag since 10 October when he moved to south Gabon and we were starting to get worried. Early this morning, however, we received some poor quality signals which reveal that he may have moved west and may now be in the Crystal Mountain area of south-western Congo. We will have to wait for better signals to confirm whether this is a real movement but we are relieved to have some received some news. 

By the 28 September, Tor had left the Kano region and was in the Yobe region of Nigeria, 350km (200 miles) to the east. The next (poor quality) signal we received from his tag was 975km (600 miles) further south in Cameroon on 7 October. By the early hours of this morning he had completed a further 700km (430 miles) and was in Gabon, close to the south-eastern border with Congo.  This new position puts him as far south as David.

Since the 24 August Tor has been gradually moving westwards. Signals received early this morning show he is now 410km (255 miles) further west than he was 5 days ago. He is now 50km (32 miles) from the city of Kano, the capital of the Kano region, which has the second largest population in Nigeria after Lagos.