Scientists at the BTO (British Trust for Ornithology) have announced that PJ, a Cuckoo they fitted with a satellite tag back in 2016, has once again returned to his breeding grounds in Suffolk. Last year he became the first tagged Cuckoo to be observed over five full migration cycles. We have now followed him over almost 96,000 km (60,000 miles) – his arrival this year marks at least the seventh breeding season this extraordinary bird has spent in the UK.
PJ is part of a BTO tracking project designed to help us understand why the UK Cuckoo population has declined by 38% in just 23 years. The picture is particularly poor in England, where almost three-quarters have been lost, while in Scotland the species is doing rather better, having increased by more than half over the same period. BTO began tagging Cuckoos in 2011 and have since uncovered their wintering grounds and the different routes they take to and from the Congo Basin each year. Differences in survival between birds using different routes to reach the winter quarters appear to contribute to regional differences in population trends, but research into why is ongoing.
PJ began his journey home in late February, when he flew from his mid-winter location in Gabon to the Republic of Congo. From there he pushed on to Ghana and Ivory Coast, where he spent a few weeks refuelling in preparation for the non-stop Sahara crossing he began on 4 April. PJ arrived in Spain just a few days later and by 24 April was back on his territory in Suffolk.
The oldest UK Cuckoo we know of was re-caught 6 years and 11 months after he was ringed as an adult, meaning PJ will have to survive another year to vie for the crown. His achievements so far have already exceeded our wildest expectations, however, as has the longevity of his satellite tag. Welcome home PJ!
Dr Chris Hewson, Lead Scientist on the project at BTO, said: “PJ’s performance continues to amaze us. We’ve been cheering him along on his journey from Suffolk to the Congo Basin and back, and we’re extremely pleased that he’s completed it successfully, extending his record in the process.
Most importantly, the data that PJ and the other tagged Cuckoos provide are helping us to understand the pressures these birds face on their extraordinary journeys. It’s vital we learn more about these if we are to stop the Cuckoo’s captivating sound from disappearing from our countryside.”
PJ is one of six Cuckoos BTO scientists are currently tracking as the birds make their way back to the UK. BTO will be tagging more Cuckoos later this spring, so keep an eye out for them as they appear on our interactive map. You can find this – and sponsor a Cuckoo yourself – at www.bto.org/cuckoos.
