Updates from our Cuckoos

Transmissions from the last few days show that all four Cuckoos which have returned to their breeding grounds are still in their respective areas. They are likely to remain in and around these areas looking for breeding opportunities for at least the next month.We now assume Lloyd has perished in Morocco as there is no reason for him to remain in his current position for so long. Last year, the earliest Cuckoo to leave the UK was Chris, on the 11 June, while David and BB left on 18 and Chance on the 22 June. Wallace, one of the birds tagged in Scotland last year, was the last to leave, transmitting from outside the UK on 23 July, just one day later than the last bird, Lyster, in 2011. 

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.

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? 

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!

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!