Updates from our Cuckoos

The net was set in the dark and as dawn broke the team were treated not just to calling Cuckoos but half a dozen Hobbys, which were feeding low over the disused gravel pits where they were tagging. The first Cuckoo caught was the one tagged, being a good weight, and still carrying a few juvenile feathers - this is Attenborough! Attenborough is still at his breeding grounds in Norfolk.

After being unable to tag any Cuckoos in 2020 due to COVID-19 restrictions, we are delighted to be able to introduce eleven new Cuckoos this year!

The tagging teams faced some very early starts as usual to tag the Cuckoos, but they were rewarded with birds who were interested enough in the female lure to be caught, weighed and tagged (with the exception of a location near Loch Katrine where there were a number of female Cuckoos around, making our lure less convincing!).

Some of these newly-tagged birds have already begun their migration south, with one in France, one in the Netherlands and one of the Scottish birds is already down in Essex.

Keep an eye on the individual birds' blogs for updates on their progress.

After five years and a staggering 50,000 miles, Suffolk Cuckoo PJ has once again returned from Africa to his breeding grounds in the King's Forest, Suffolk. He is the first of our tagged Cuckoos to survive five complete migrations with his tag still functioning. When we last updated you he was having a well deserved rest on the Isle of Wight, but despite the many attractions of that fine place, it couldn't keep him away from East Anglia for long. New updates received from PJ's tag at 07:30 yesterday morning (Friday 22nd April) showed that he had covered the final 223km (139 miles) from the Isle of Wight to Suffolk. Further updates since show him flying around his breeding grounds, less than 5 miles from us here at BTO HQ in Thetford. He will stay here until early July before beginning his journey back to Africa once again.

We caught and tagged Cuckoo 'PJ' in the King's Forest, Suffolk, in June 2016, and since then he has provided us with a wealth of valuable data. Through tracking PJ's migrations between UK and Africa, we have discovered that he spends the winter months in north-western Angola. Recently, while en-route to the UK he has spent several weeks feeding up in Ivory Coast and over the last few days we can see that he has tackled the mighty Sahara. He was in, or over, Mauritania on Sunday morning and by 8am yesterday morning (Monday) he had reached Morocco! The most recent update, which arrived at 19:40 last night, showed him in northern Morocco. He is currently in the Middle Atlas Mountains, approximately 95 km (59 miles) south east of Fes. From here, he will move up through Spain and France before crossing into England.

If he makes it back to Suffolk this year, PJ will have completed his fifth tracked migration, which is the most for any Cuckoo that we have tracked so far! It has been a nerve-racking time waiting for PJ to tackle the desert and we'll be keeping everything crossed that the rest of his journey goes smoothly. In previous years, he has successfully completed his desert crossing between 7th and 17th April and arrived back at his breeding grounds in Suffolk between 18th and 30th April, so he is close to his usual schedule.

Sadly, it looks as if we have heard the last from Valentine. When his tag last transmitted, the battery in his tag was low on charge and had been for some time, but there's also an indication of a problem based on temperature. The temperature sensor in the tag reported about 8 degrees C lower than any of the previous readings in Angola, including those from similar times of day, and we don't think the move north by a few hundred km explains this. We suspect that Valentine perished between the last location in Angola (2nd Feb) and the ones in southwest DRC (16th Feb). Valentine was tagged in June 2019 so we have benefited from a lot of valuable data from Valentine, helping us extend our knowledge and understanding of this amazing species.