Updates from our Cuckoos

Chris’s last transmission was on 14 October. He is still close to the  Likouala aux Herbes, the same area of Congo that he has been in since 28 September.

BB’s tag transmitted locations over the weekend showing that he remained in Chad.  Meanwhile, we have not received any further transmissions from Roy's tag since the 6 October. Whilst we had no cause for concern for Wallace when his tag last transmitted on the 14 September, the longer the silence continues, the more we wonder why.

Chance was the most northerly of all the Cuckoos from which we are still receiving regular transmissions. However, movements early this morning show that he has moved from his location north of Lake Chad and travelled south into Cameroon.  He covered around 686km (426 miles) south to a location close to the edge of the Mbang Mountain region before moving 80km (50 miles) back north, presumably in search of better conditions. 

On the afternoon of 13 October Lloyd was still in the Janub Dafar area of Sudan.  Two days later, on the eve of 15 October, Lloyd had covered a distance of around 299km (186 miles) in a southerly direction and was in South Sudan, close to the border with Central African Republic. 

Over the weekend we received transmissions from David's tag who is still settled in Democratic Republic of Congo. There has been nothing further from Indy since 21 September.

We worried whether Lloyd would be able to make a decent attempt at a desert crossing from such a late starting point in Italy and we were also convinced by his trip to the Perpignan region at the end of August that he would attempt to reach Africa via Spain.  So the series of locations received during the evening of Wednesday 3 October through to early morning 4 October was doubly surprising, as they showed him not only making apparently good progress south over the Sahara but also that he was doing so over the Egyptian desert, only about 200km (125 miles) west of the Nile valley!

Lloyd is crossing further east than even BB, whose crossing at the longitude of the border between Libya and Egypt was the previous most easterly, which is the opposite of what we suspected he would do. It appears that the trip to Perpignan was probably simply a movement looking for a good foraging location rather than an aborted attempt to migrate through Iberia – Lloyd moved around southern Europe more than the other Cuckoos both before and after reaching the spot in north-western Italy that he ended up returning to at the end of August to carry out his desert crossing preparations.

Lloyd’s tag is due to resume transmissions early on Saturday 6 August, when we hope he will he will be safely across the desert. It will be interesting to see if he stops further south than the other Cuckoos did, as the Sahel will be beginning to dry out by as the rain associated with the ITCZ has moved off south.

Between 27 and 29 September, David moved 970km (603 miles) SSW from his location close to the border between Sudan and South Sudan. This placed him in some wet rainforest close to the Congo River in Tshopo District of DRC, a habitat occupied by poorly known animals such as the Okapi, a forest-dwelling relative of the giraffe, as well as the Bonobo, closest living relatives of humans, and a recently discovered species of monkey.  He didn’t stay in this area long, though, and by this morning (2 October) he had moved a further 570km (354 miles) SW to a location quite close to the southern edge of the continuous rainforest in Mai-Ndombe District. He has progressed by 1570km (976 miles) in five days.

At about 3°S, David is now the most southerly of the tracked Cuckoos and is nearly as far south as the most southerly tracked Cuckoo reached last year (which was Kasper at about 4°S). If he continues along this path for about another 160km (100 miles), David will reach an area of savannah habitat with gallery forest similar to the Teke Plateau in which four of the Cuckoos tracked last winter spent the mid-winter period. 

Having previously moved eastwards in southern Sudan, just north of South Sudan, we wondered whether David (and Roy) were heading to somewhere very different to last year’s Cuckoo. Like Roy, however, David has now headed off on a bearing west of south, back towards the wintering grounds of last year’s tracked birds. It’s not clear why Daivd moved so far eastwards first but it is notable that he moved across the northern edge of the Chaine des Mongos mountain range in northern CAR, whereas the routes of the other birds took them to its west, so he appears to have simply avoided the mountains via a different route. 

Sometime between 20 and 22 September, Roy moved 94km (59 miles) ESE, thereby crossing the Oubangui River and moving from CAR into the Democratic Republic of Congo (DRC). He has moved from a savannah landscape with gallery forest to a landscape dominated by forest but still with plenty of open patches and edges – based on what we saw last winter, this looks like very nice habitat for a Cuckoo. 

BB and Chance remain in Chad and have transmitted in the last couple of days. Chance is still in the vicinity of Lake Chad while BB is further south.