BTO Blackcaps in Cornwall 2020/21

BTO/Universities of Oxford and Exeter Blackcap Colour Ring and Evolution Project

Colour-ringed Blackcaps – R Phillips

An ongoing study, coordinated by Oxford University and BTO, is investigating the wintering behaviour, movements, and breeding origin of Blackcaps that winter in Britain and Ireland, as we still know surprisingly little about these birds that now spend the winter with us. A key component of this project is a long-term colour ringing study to help monitor the potential effects of climate change and evolution of this novel migration strategy.

Over the last three winters more than 600 wintering Blackcap have been colour ringed and around 130 fitted with geolocators, across Britain and Ireland, to track their migration and movements. A large portion of these birds have been marked in Cornwall, particularly in the Falmouth/Penryn area, but they could turn up anywhere.

If you see a Blackcap or have them visiting you garden, please check their legs for rings. Each bird has a total of three colour rings and a metal BTO ring, two rings on each leg. The combination of rings allows us to identify each individual and we can provide a history of it’s movements. Please get a photo, or note the order of the rings on the right and left legs, so that we can identify the bird.

Please report details to Greg Conway and Benjamin Van Doren at:

More information on the BTO project can be found here –

Individual variability and versatility in an eco-evolutionary model of avian migration – New collaborative research, involving BTO, has used tiny tracking devices to investigate unanswered questions about Blackcap migration.

Blackcap-article-2017.pdf  – An article investigating the reasons Blackcaps winter with us

How to spot a Blackcap – Identification tips from the BTO (including a handy video)

Enjoy watching your Blackcaps, in the garden or elsewhere – the CBWPS would also like to receive all sightings of Blackcaps in Cornwall to the normal email sightings address – please send to , and  we will also forward on all sightings of colour-ringed Blackcaps to the team. 

Thankyou and Happy Birding