Updates from our Cuckoos

By the 28 February, Derek had moved from Congo to central Cameroon.  This morning, 7 March, we received signals showing he had covered a further 1490km (925 miles), which puts him to the west of Lake Volta in Ghana. He is the third of our tagged Cuckoos in West Africa but is further to the west than Ken who has remained in Nigeria.

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’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?

Over the course of the 1 March, Waller headed further west from his position just north of Lake Volta, travelling 465km (290 miles) and flying across the middle of Ghana. He arrived in Ivory Coast in the late afternoon and was 90km (55 miles) inside its border with Ghana.  At the moment he is 1300km (810 miles) further west than any of the other Cuckoos. Ken moved over the weekend and is officially in West Africa now. 

Ken has moved 200km (120 miles) from his last position in Cameroon and into Nigeria over the weekend. He is now officially in West Africa and is the second Cuckoo to move this far west this year.  

Waller has become the first of our tagged Cuckoos to move to West Africa!  The last signal placing him in Cameroon was received on 20 February and by the 27 February he had travelled a huge 1445km (900 miles), flying over Nigeria, Benin and Togo to reach Ghana. The latest signals reveal he is in eastern Ghana, 85km (52 miles) north of the northern edge of Lake Volta. 

This is the first return migration that we have followed for Scottish Cuckoo Waller but it's interesting to note that last year the first Cuckoo to move west was Chance, another of our Scottish Cuckoos. He also spent a few weeks in Cameroon before moving to Lake Volta in Ghana around the 25 February - very similar timing to Waller!  This timing does raise fresh concern that something has happened to either Chance, or his tag, as we have not received signals since 4 December and, given his timings last year, he should be on the move. 

Sometime between the early hours of 24 February and lunchtime on the 26 February, BB made another move north, leaving Gabon behind. During that time he covered 390km (240 miles) to reach  the Mbam et Djerem National Park in central Cameroon.  From the satellite images you can see he is now out of the thick cover of the Congo rainforest and in the edge of some forest, where the tree coverage thins out. 

Derek has travelled a small distance south-east from his last position. The most recent signal, received on 21 February, shows he is currently  near a tributary of the Congo river, close to Site Lac Tele-Likouala Aux Herbes.  Now that Chris has moved north, Derek is the most southerly Cuckoo.  Will he also move north shortly? 

David has travelled only a small distance since he made the jump across the Congo rainforest block at the end of January. Having been in the location for 25 days now we expect that he has been feeding up and resting, ready to make the next move west along the edge of the forest. By this time last year he was 400km (250 miles) further west,  he then continued to move west over the next month and in late March, made a big move to Ghana. Will he do the same this year? If so we might expect a further westerly movement any time.  

On the afternoon of the 20 February, Chris's tag sent tranmissions from southern Congo but, by early morning on 25 February, he had travelled 930km (580 miles) to reach a location in the  south-west of the Central African Republic. He has now flown right over the block of Congo rainforest, and is very close to it's northern edge. Its the first time we have seen him do this, largely because in previous winters he hasn't travelled so far south, instead choosing the swamp forests of eastern Congo.  He is just 80km (50 miles) south of David, the most northerly tagged Cuckoo, who moved to the edge of the forest at the very end of January. 

It's amazing that we are still gathering data for Chris having first tagged him in spring 2011. We now have three southward autumn migrations and two northward spring migrations for him.  Having taken up a different wintering location this year, it will be really interesting to see whether this changes his return strategy. We are keeping our fingers crossed for his safe return once again to the UK.