Tracking migrants

Tagging birds to discover the secrets of their migratory journeys.

Turtle dove caught and tagged at Lawford in Essex


We know relatively little about the ecology of our long-distance migrants once they leave the breeding grounds and this includes such basic information as where they spend the winter, the routes they take to get there and the places they stop along the way. This lack of knowledge could hamper us in our attempts to understand what is causing the declines of migrant populations and, importantly, what we can do to reverse these species’ fortunes.

The continuing development and miniaturisation of tracking technology is allowing us to follow the journeys of migrant birds, sometimes in real time, giving us an insight into migratory behaviour and how this can impact upon the population dynamics of these species.

Dependent on the size of the species involved, we have utilised three particular types of technology: geolocators, which record and store light levels to estimate longitude and latitude, GPS tags which both need to be retrieved to access the data and PTT satellite tags that can be tracked in real time as a bird’s location is transmitted to orbiting satellites and relayed back to us on Earth.


  • To enhance our understanding of the migratory ecology of our priority long-distance migrants through the use of tracking technology.

Key Dates

  • 2012-present: Use of satellite tags to track European turtle doves in eastern England.
  • 2012-present: Use of light-level geolocators to track whinchat, ring ouzel, wood warbler. spotted flycatcher, pied flycatcher.
  • 2013-14: Tested safety and efficacy of harness design and attachment method on whinchats in Nigeria.
  • 2016: Fitted GPS tags to common swifts to study breeding season foraging behaviour and migratory movements.
  • 2017: Four satellite tags fitted to European turtle doves in Senegal.


  • Tagged 17 turtle doves 2012-2016 in UK.
  • Tagged four turtle doves in Senegal March 2017.
  • Pied flycatchers: two tags retrieved in 2014; further tagging 2015 and 2016.
  • Whinchat: trialled safety and efficacy of harness design and attachment method in Nigeria, 2013/14; 21 tagged at Geltsdale RSPB reserve, Cumbria, and Exmoor, Devon, 2016.
  • Wood warbler: first time tagged in UK, Devon and New Forest (BTO).
  • Spotted flycatcher: First time tagged anywhere, Devon and Cambridgeshire (BTO).
  • Ring ouzel: one geolocator retrieved from Scotland in 2014; GPS tags fitted in 2015, but no data retrieved.
  • Common swift: GPS tagging in Northern Ireland in 2016.

Planned Work

Following the tagging carried out in 2016, we hope to retrieve tags from whinchats, wood warblers and pied flycatchers in 2017.

We also plan to fit a further 70 geolocators to whinchats (at Geltsdale and Exmoor) and 80 to pied flycatchers (at Dartmoor National Nature Reserve). Last year was the first time that tags had been fitted to wood warblers and spotted flycatchers, so in 2017 we plan to only retrieve tags and monitor colour-ringed birds to build up a picture of the safety and efficacy of tagging these species, with a view to carry out more tagging in 2018.

We plan to fit a further 10 satellite tags to European turtle doves, but the location of this will be dependent on permission from the Special Marks Technical Panel.

Further GPS tagging of common swifts will be carried out in Northern Ireland to look at both breeding season foraging and migratory journeys.


The wintering grounds of pied flycatchers tagged on Dartmoor in Devon were found to be either in Liberia or south-east Guinea (Ouwehand et al. 2016).

Comparing populations from across Europe, there was evidence for migratory connectivity, with birds from different breeding populations wintering in different areas. Data from one tagged (geolocator) ring ouzel was retrieved in 2014. This bird was found to stop over in the Bordeaux region of south-west France for more than two weeks, before spending four months in the Atlas Mountains of Algeria, close to the border with Morocco, but further east than the majority of British ringing recoveries (Sim et al. 2015).

Whinchats tagged in 40 square kilometres in Nigeria were found in summer more than 2.2 million square kilometres across central and Eastern Europe (Blackburn et al. in prep). Our chances of tagging whinchats in the UK was greatly enhanced by an experiment in Nigeria (Blackburn et al. 2016) which demonstrated the safety and efficacy of the technique.

Satellite tagging of turtle doves has shown that birds from the UK and France follow a similar route along the ‘western flyway’ through France, Iberia, Morocco, across the Sahara into Mauretania, and wintering between The Gambia and Mali. Morocco constitutes an important stopover on the return spring migration.



Coast on a stormy day

Dr John Mallord

Senior Conservation Scientist, Conservation Science
Coast on a stormy day

Dr Malcolm Burgess

Principal Conservation Scientist, Conservation Science
Coast on a stormy day

Dr Innes Sim

Conservation Scientist, Conservation Science
Coast on a stormy day

Dr Kendrew Colhoun

Senior Conservation Scientist, Reserves Team
Tagged with: Country: England Country: Northern Ireland Country: Scotland Country: Algeria Country: France Country: Gambia Country: Guinea Country: Liberia Country: Mali Country: Mauritania Country: Morocco Country: Nigeria Country: Portugal Country: Senegal Country: Spain Country: Western Sahara Habitat: Farmland Habitat: Grassland Habitat: Upland Habitat: Urban and suburban Habitat: Woodland Species: Pied flycatcher Species: Ring ouzel Species: Spotted flycatcher Species: Swift Species: Turtle dove Species: Whinchat Species: Wood warbler Project status: Ongoing Project types: Research