Bowie joins the Cuckoo class of 2018

No.:  2018-20
July 2018

As part of its hugely successful Cuckoo project the British Trust for Ornithology (BTO) has just launched 10 new birds, bringing the number of Cuckoos that are currently being tracked to 14; one of which has been named Bowie by wildlife TV presenter Chris Packham.

Bowie the Cuckoo, named after one of Chris’s favourite musicians David Bowie, was tagged on Tuesday 22 May, 2018 in Bolderwood, New Forest, Hampshire. On 12 June his tag transmitted outside of the UK for the first time and showed that he had left the New Forest and was in France, just to the south of Orleans; Bowie’s migration journey had commenced. He is currently north of Montlucon in central France and around 600km from his tagging site.

The project was launched in 2011 to help identify what might be driving the decline of this species in the UK, we have lost almost three-quarters of our breeding Cuckoos since 1990. This project has revealed the life histories of individual Cuckoos to scientists and the public alike, for the first time, uncovering the migration routes taken and possible causes behind the decline.

Since the beginning of the project, 80 cuckoos have been fitted with state of the art satellite tags and have revealed where British Cuckoos travel to for the winter months, and the journey that these birds take to get to their final destination. It’s now known that the winter months are spent in the Congo rainforest, arriving in September and leaving via West Africa in February. Heading south the birds use one of two different routes; either through Spain or Italy, yet all winter in the same part of Central Africa - a migration pattern that was new to science when uncovered by this project. At the moment it is uncertain which route Bowie will take; but the route chosen may well determine his chances of survival.

The survival rates for the two routes are very different with those migrating via Spain surviving less well. To date all of the Cuckoos that have gone through Spain have come from England, where Cuckoos are declining at a rapid rate. All of the Cuckoos tagged in Wales and Scotland have taken the Italian route; in Scotland numbers are increasing, whilst in Wales numbers are mostly stable.

Dr Chris Hewson, lead scientist on the project at BTO, said, “The route a Cuckoo takes on migration seems to play a big part in its chances of survival, and that this could have a big impact on the Cuckoo population in different parts of the UK. One of the things we need to understand is what determines the chosen route. Do they come from genetically different populations, for instance? We're and looking forward to seeing which route they use over the next couple of weeks.”

Anyone can follow Bowie’s adventures and see which route he takes to the Congo Rainforest, on the BTO website at:
https://www.bto.org/science/migration/tracking-studies/cuckoo-tracking/bowie

You can support Bowie and the rest of the Cuckoos by visiting the link below and choosing to sponsor a Cuckoo, buying a gift pack or making a donation. www.bto.org/cuckoos

Contact Details

Paul Stancliffe
(BTO Media Manager)
Office: 01842 750050
(9am to 5:30pm Mon-Thurs), (9am to 5pm Friday)
Mobile: 07585 440910
Email: press [at] bto.org ()

Chris Hewson
(Senior Research Ecologist)
Office: 01842 750050
(9am to 5:30pm Mon-Thurs), (9am to 5pm Friday)
Email: chris.hewson [at] bto.org (chris.hewson)chris.hewson [at] bto.org (@bto.org)

Images are available for use alongside this News Release. 
Please contact images [at] bto.org quoting reference July 2018 - 20

The BTO has an ISDN line available for radio interviews. 
Please contact us to book an interview. Office:01842 750050

Notes to editors
1.
The locations where the class of 2018 have been tagged are Thetford Forest in Norfolk, Sherwood Forest in Nottinghamshire, The New Forest in Hampshire, Knepp Estate in Sussex and Carlton Marshes in Suffolk. The birds have been named Sherwood, Robinson, Knepp, Raymond, Lambert, Carlton II, Cameron, Bowie, Sylvester and Thomas. More information on each can be found here.

2. Continuing to tag in future years. Not only does continuing to tag Cuckoos help gain more information, but it also allows us to understand similarities and differences within the Cuckoos we tag.  It also means that we are more likely to have Cuckoos providing us with information over a number of years rather than one or two, this means we can easily look at the differences with weather conditions and other factors that could change each year and how these factors affect the Cuckoos travel.  We can see whether birds that do ‘unusual’ things survive better or worse than others, giving insight into what limits the normal range of the population. 

3. What we have found out so far:

  • Return routes - The Cuckoos followed so far take a different return route to the UK than the one they followed on their outward autumn migration. No matter which route they take south, whether it be via Spain, Italy or further east, all the Cuckoos head to West Africa to make the return crossing over the Sahara to Europe. This information suggests that there are good reasons why Cuckoos visit West Africa on their way back and this is another important aspect of their journey which could prove a pinch point in their success.
  • British Cuckoos - Using data collected in previous years we were able to find out that although the Cuckoos we tag in Britain are referred to by us as ‘British’ Cuckoos, these Cuckoos only spend a small amount of time in Britain. One of the Cuckoos we tagged at the start of the project spent just 15% of his time in Britain, spending most of his time in Africa (47%) and the rest on migration (38%).
  • Mortality - Having followed Cuckoos over a number of years we are beginning to gather a wealth of data about the difficult points during the Cuckoo’s annual cycle. Knowing where the birds are struggling (and dying) will help us understand how their numbers change and hopefully will help to identify the causes of their declines to help inform conservation in the future. 

4. The BTO is the UK's leading bird research charity. A growing membership and up to 60,000 volunteer birdwatchers contribute to the BTO's surveys, collecting information that underpins conservation action in the UK. The BTO maintains a staff of 100 at its offices in Thetford, Stirling, Bangor (Wales) and Bangor (Northern Ireland), who analyse and publicise the results of surveys and projects. The BTO's work is funded by BTO supporters, government, trusts, industry and conservation organisations.