Updates from our Cuckoos

PJ, who is on his fifth tracked annual migration to the UK from Africa, has spent the last couple of weeks in Ivory Coast. The rains are well established in the area that he's stopped off in - in fact, there's been a bit more than expected over the past month (up to 75mm). This should mean there's plenty of food for him. We don't know exactly what he'll be feeding on but expect that this will include some adult insects that have been aestivating over the dry season and have emerged in response to the start of the rains.

The area PJ is in was originally deciduous forest that has been transformed into secondary growth - this transformation might originally have been beneficial for Cuckoos, but depending on the extent of tree loss, it could reduce habitat quality for them. As it's now a few weeks since the rains commenced, it's likely that in addition to emergent insects, there could also be plenty of caterpillars (Cuckoos preferred prey on the breeding grounds) for him to eat by now. He's likely to use this fuel to put on fat amounting to at least 50% of his lean body mass, as well as enlarging his flight muscles, before migrating over the Sahara. He usually spends most of March in Ivory Coast before heading north across the Sahara.

Carlton II has followed PJ's lead and has started his migration back to the UK. He has spent the winter in central Gabon and over the last few days he has flown 300 km (186 miles) north towards the border between Gabon and Cameroon, and is now in the Minkebe National Park in north east Gabon. Carlton II was tagged in the spring of 2018, and in 2019 he made his first move north on 15 March. Last year he started his journey on 7 March, so he is a couple of weeks ahead of schedule this year. His route back to the UK will take him out to Ivory Coast, Liberia or Sierra Leone in West Africa where he will feed up before embarking on his Sahara crossing.