Updates from our Cuckoos

It seems that Chris is in no hurry to get back to the UK, in fact, he has begun to head south again. Yesterday he was close to the French town of Suippes, and around 80km (50 miles) south of the Belgian border. Having been as close as 210km (130 miles) to the English coast, he is now 100km (60 miles) further south. It is beginning to look like he might well stay in France this year. However, there is still plenty of time for him to change his mind.

Locations received this morning show that Chance remains in the foothills of the Pyrenees. He has now been there for three days, despite conditions having been good for onward migration. He may need to rest and refuel before continuing his migration – it will be interesting to see how long he stays here before moving on. Currently, three of our tracked cuckoos are in Spain, with David and BB both further west than any of the other tracked cuckoos have been recorded in Europe. 

The duty cycle of Chris’ tag has been resetting, possibly due to him perching on power lines. Consequently, we received unexpected additional locations throughout Tuesday and Wednesday (16 and 17 April) which showed he moved from Belgium into France, to the west of the Ardennes Mountains. Although it’s not possible to be precise, he appears to have been in the Parc Naturel Régional de l’Avesnois in Nord Pas-de-Calais region. The area is characterised by the ‘bocage’ landscape – small pastures surrounded by hedges and interspersed by blocks of woodland of various sizes. As we have seen elsewhere including in Africa, areas with mixtures of woodland and grassland make excellent cuckoo habitat. Will Chris find this area more to his liking than the Thetford Forest area and stay here through the breeding season? 

A location received this morning (18 April) showed that he remains in Ivory Coast and that the charge on his tag is still low. 

A series of locations received yesterday evening (Monday 15 April) showed that BB was heading across the desert in northern Mauritania, about 460km (286 miles) E of David’s last position. Over the course of 5 hours he travelled approximately 160km (100 miles) more or less due N. If he follows a similar route to Chance, around the eastern end of the High Atlas, BB would have another 1,000km (620 miles) to travel before reaching the Atlas Mountains and 1,400km (870 miles) to the Mediterranean coast. If he went to the west of the High Atlas, he would come to hospitable conditions at Agadir on the Moroccan coast in 700km (435 miles). One possible advantage  of stopping over so far west in Africa would have been to reduce the desert crossing by 25% or so (from around 1,900km to around 1,400km) by taking a route west of the High Atlas and along the Moroccan coast, so we had wondered whether David & BB would  do this.

As hoped, David’s faltering tag has charged well enough for transmissions to resume during his desert crossing.  Four transmissions were received this morning placing him in north-western Mauritania, close to the border with Western Sahara. Unfortunately, all four placed him in approximately the same place and he doesn’t appear to have moved at all during the three hours after dawn. Although we have seen cuckoos stopped in the desert during the day only to resume migration and successfully complete the crossing, it would be very unusual for one to do this so early in the day. We are concerned about this situation but hope for good news when David’s tag begins its next transmissions on Wednesday.

We haven’t heard from Lloyd’s tag since Saturday afternoon (13 April), when he remained in Ivory Coast but the charge on his tag was very low. He is the last of our tracked cuckoos south of the Sahara and as he has been in Ivory Coast for a week now and was in Ghana for a week before that, we might expect him to make a move north quite soon.  

When Chris’ tag resumed transmissions early this morning it revealed he had indeed continued northward, as expected – but not to England! A series of locations placed him in southern Belgium and although each was an unconfirmed location whose accuracy couldn’t be assessed, taken together they indicate that he was travelling slowly westwards around the northern periphery of the Ardennes Mountains. Chris’ current location is within 100km of the areas that he stopped over in the late summers of 2011 and 2012 and in fact visited this very area during his ‘mini-tour’ of NW Europe last June but we had no indication that he visited the area last spring. Will he stay here for a while before returning to England? Will he defy expectations and not return to England at all this spring? Watch this space!

Having been in the latter stages of his desert crossing early on Tuesday morning, we had expected Chance to have moved into Spain by the time of the next transmissions due on Saturday (13 April). A series of locations received throughout that day showed that he had indeed done that, progressing a further 1135km (705 miles) N and stopping in the northern part of Aragon region, in the foothills of the Pyrenees. It is interesting that he has reached the central part of the mountains, with no indication of him attempting to go around one side or the other. Based on what we saw last spring and so far this spring from Chris, the speed at which he progresses from here back to Britain may depend on how favourable weather conditions are. Over the past two days, they do appear to have been favourable so it will be interesting to see where he is when his tag starts transmitting again this evening. 

When Chris’ tag resumed transmissions as the skies cleared on Saturday evening (13 April), two locations showed he was still south of Autun in Burgundy, central France. Between the times of the two locations, however, his tag’s temperature dropped by 4 degrees C, probably indicating the initiation of migration, and sure enough, an hour and a half later he was 80km (50 miles) to the NNW. In total, Chris advanced about 120km (75 miles) in the 3.5 hours after dusk. Further unconfirmed locations for the early hours of Sunday morning suggested that he had stopped about 80km (50 miles) to the east of Paris, possibly due to the rain that lay to his north. If indeed he did stop here, we expect he would have resumed his migration the next night so it is likely that when his tag comes on again on Tuesday morning, he will be back in England – watch this space!