Updates from our Cuckoos

The last few weeks have been quiet and for those who had not yet completed their desert crossings, it looks like the challenging conditions have claimed more of our tagged Cuckoos.

Unfortunately no further signals have been received from Knepp. From the temperature data and movements at the time, he was alive on 12 July, when we last heard from his tag. Though the battery charge had been low for a few days, there is no evidence of long term battery decline so we can't be sure what has happened to him - either he, or the tag, appear to have died suddenly. 

Lambert, who was still in France, has not moved on south and signals on 21 August showed high temperature fluctuations across the day, indicating the bird's body temperature and behaviour were not regulating it. We've heard nothing since then, and his tags battery charge had suddenly dipped, all of which leads us to believe he has likely died.

Unfortunately the challenging conditions have also impacted on Nussey who has already attempted two trips to Africa and retreated to Europe.  Abnormally low temperatures were received at the time of the last messages (16 August), having previously been fine. He was not migrating at that time, so the low temperatures were not due to high altitude, and the battery was also much lower than previously, further suggesting he was dead.

The droughts and exceptionally high temperatures in Europe appear to have proved difficult for our Cuckoos this year, however the five south of the Sahara are still regularly transmitting. Valentine, PJ, Carlton II and Tennysons' tags have all sent signals during September and the last signals received from Senan's tag were at the end of August and show him still in Burkina Faso.

There have been no further signals from Knepp since 12 July when the battery in his tag was functioning well. Given that there is no evidence that his battery was failing, his sudden disappearance just a day after arrival at his last known position means we are now seriously concerned that we won't hear anything more from Knepp. 

Knepp is now 595 km (370 miles) south west of his last location in south west France and is just 1.5 km (1 mile) south of the shore of the Valparaíso Reservoir in the province of Zamora, Castile and León, Spain. He is very close to the village of Villardeciervos. Knepp also stopped in this area last year but was 26 km (16 miles) south west of here, nearer the town of Trabazos, where he stayed until July 28 before crossing into Morocco.