Citizen Science helps to understand more about Cuckoo decline
Public help over the last two years is providing a better understanding of the lives of one of our most iconic birds.
The ‘Flight of the Cuckoo’ Project, which is a partnership between Dartmoor National Park (DNP), Devon Birds and Exeter University, has now completed its third year with the public being asked to report their cuckoo sightings for the past two seasons.
The sighting report project was first run in 2014, and the project partners are very pleased with the enthusiasm of the public response again this year, having received double the number of reports from the previous year.
The public were asked to report cuckoos they had seen or heard on a live web map, or, more traditionally, by filling in a paper form or telling a member of Dartmoor National Park staff or Devon Birds. The records submitted can be seen on the sightings map on the Devon Birds website www.devonbirds.org/cuckoos.
Whilst this sadly this doesn’t mean there are twice as many cuckoos on Dartmoor as there were last year, it does mean a more accurate picture of arrival times, departure times, cuckoo density and preferred locations on the moor.
Naomi Barker, DNP Ecologist, said: ‘The response from the public and the ornithological community has been remarkable. In England the decline in the cuckoo population has been in the order of 70% over the last 20 years.
The data shows how important Dartmoor is for cuckoos within the count, with 90% of the sightings being within the National Park. Their preferred habitat is the moorland fringe, with fewer records from the wooded valleys and enclosed farmland, and virtually no records from the high moor.’
George Harris, Chairman of Devon Birds, said: ‘The interactive map proved to be very popular again. We plan to publish our new Devon Atlas in Jan 2016 where you will see a comparison of cuckoo distribution 30 years ago and now. It shows that cuckoos have almost entirely retreated to Dartmoor for breeding as this is where their host species the meadow pipit still breeds in large numbers.’
Sara Zonneveld, University of Exeter PhD candidate who is studying the breeding requirements of cuckoos and ground-nesting birds on Dartmoor, said: ‘We received over 1,300 sightings from 746 members of the public, a truly fantastic result. Records were submitted between 5 April and 2 July, which means we have records across the entire cuckoo breeding season. This year, we received over 150 sightings from locations outside Dartmoor, giving us valuable information on possible cuckoo strongholds in other Devon areas.’
No cuckoos were tagged this year (seven Dartmoor cuckoos were tagged in 2013 and 2014) and sadly, there are no more ‘active’ Dartmoor cuckoos transmitting signals. The project lost touch with the final two cuckoos, Whortle and Emsworthy, in the early spring of 2015. This does not necessarily mean that all seven tagged cuckoos have perished, as it is possible that the satellite tag has failed. This appears to be the case for at least one Dartmoor cuckoo: a cuckoo with a satellite tag (thought to be Emsworthy) was seen and photographed on Dartmoor in May this year, despite no satellite signals being received.
This year, cuckoos were tagged from the northwest and the northeast of England, thereby increasing the geographic spread of tagged cuckoos across the country, to try and generate a better understanding of how cuckoos behave and what migration routes they choose in different parts of the UK. All British cuckoos have now arrived in Africa, with about a third already in the Central African rainforests, and the remainder recovering from the Sahara crossing in the Sahel region.
Whilst the records of sightings will not give an accurate picture of the number of cuckoos on Dartmoor it does indicate some of the key areas used by the birds. Meanwhile the satellite tag data is starting to indicate key migration points for the birds to ‘refuel’ and areas of potential importance for wintering in Africa.
You can view the journeys Dartmoor cuckoos took by going to www.bto.org/cuckoos
