Tracking Cuckoos to Africa... and back again

We’ve lost over half the number of Cuckoos in the UK over the last 20 years.

Since 2011 we’ve been satellite-tracking Cuckoos to find out why. We’ve learned lots of vital information which could help us to understand our Cuckoos -  such as how the different routes taken are linked to declines, and some of the pressures they face whilst on migration. 

But there is still more to discover. We now need to look more closely at how dependent they are on, and how much their migration is linked, to the drought-busting rains of the weather frontal system known as the Inter Tropical Convergence Zone (ITCZ) as they move out of the Congo rainforest and begin to head back to the UK via West Africa.

This project wouldn't have been possible without the amazing support from funders and sponsors. Read more about the project and find out how you can get involved.

We have been able to share our expertise around tracking Cuckoos with other international studies, such as the Beijing Cuckoo Project.

Follow our Cuckoos as they move to and from Africa.


Cuckoo movements from 23 May 2017 to 16 November 2017

View routes starting..
Cuckoo positions on

Latest News

Cuckoo class of 2017 - 15 Nov 2017

In 2017, we have been trialling the very latest satellite tracking technology - this year’s cohort were tagged with 2g tags from Microwave Telemetry.

We have, unfortunately, ‘lost’ contact with most of them already. It would seem that the smaller size of the new tag allows the solar panel, used to recharge the tiny battery, to become shaded by feathers, resulting in much less efficient charging of the battery, and consequently lower contact with the tag. Although some may have died, the lack of transmissions from the tags makes it impossible to assess this and in all cases, there were no indications that the birds were in trouble when we last heard from their tags.

This is exacerbated during the winter months by the birds spending more time under the canopy in the Congo rainforest. We don’t know how the batteries will fare when the birds begin their northward migration back to the UK. On leaving the rainforest the tags should receive more sunlight which might be enough to overcome feather shading, and if this happens some of the ‘lost birds’ could pop-up again in February or March, but it is possible that the prolonged shading will have caused irreversible damage to the much smaller batteries in the 2g model. We all have our fingers crossed.

As we move forward we are continuously looking for effective ways to continue gathering this important data for Cuckoos, and other species, to benefit our knowledge and ultimately wildlife conservation. We hope that next year we will be able to track a cohort of cuckoos without these issues arising. 

PJ moves south - 14 Nov 2017
PJ has moved 290km (180 miles) south within Congo in the last week and is now in the Lekoumou region, 40 miles south of Bateke Plateau National Park. Last year he was in Angola by the 25 October and remained there until January so we expect him to continue moving south to reach the same area. 
Larry in Angola - 14 Nov 2017

Larry has continued south from Chad, where he's been since the beginning of September. By the 9 November he had covered 1175km (730 miles) to reach the Cuvette-Ouest region of Congo, not too far south-east from Victor in Gabon. He didn't stop here for long though and by the early afternoon of 11 November he was 760km (470 miles) further south in northern Angola.

Larry’s southward migration from the UK to Angola has been remarkable. Weather conditions during the stopover period in Italy were harsh, incredibly hot and dry conditions were experienced across the whole of the northern Mediterranean area with wildfires being a feature from Spain to Croatia. Presumably in response to these conditions, and the probable lack of invertebrate food, Larry moved north to Poland, undertaking a journey of around 1300km (800 miles), at a time when we would have expected him to head south across the Sahara. Larry spent several weeks in Poland, and it would seem a wise move, from here he was able to undertake his migration to sub-Saharan Africa via the Balkans, a part of the world we hadn’t seen him move through before. Even though his migration this autumn was unusual, he is right back at his wintering location in Angola.

In the previous two years we've been following him he has also ventured to Angola, but normally to a location in the north-east, where he has remained for a while before then heading west towards the coast. He appears to have gone directly to this area now and is north of Tomboco. It's likely that, as in previous years, he will remain here until at least mid-December or possibly even mid-January, depending on conditions. 

Get involved

Find out how you can support the project, or contact us directly for further details - cuckoos [at]

Information on this page is only for illustrative purposes and cannot be used without our permission © British Trust for Ornithology.