You will see that we have links to this site in several places but under especially under “cuckoo tracking” in recent post and interesting sites.
Phil Atkinson (Head of International Research) spoke to me about the Cuckoo tracking work that they have done and are doing . We both agree that understanding how cuckoo fledglings make their way to their wintering grounds in the Congo is a really important puzzle because, of course, the cuckoo parents are not there to guide them.
Phil was kind enough to explain some key factors about their work that I was not aware of. Firstly all the birds that he has been tracking are adult males. This means the data which has been collected thus far whilst really interesting does not resolve the issue of how fledglings make their way.
Obviously the way to discover what happens is to track fledglings but researchers at the BTO have not tagged these due to their smaller size. The smallest satellite tags currently available weigh just under 5g and there are guidelines about the maximum size of tag for a particular species. Male cuckoos are above this threshold. Females and juveniles are smaller and the plan is to track them once smaller devices become available.
Miriam Liedvogal (one of our heroes) says: “There is joint effort in tracking cuckoos from several countries (DK, UK, SE and others) and other studies working on cuckoo biology in other respects, thus there will be new data out there soon”. This is encouraging.
You will see we cover bird geolocation devices on our web site, see Biotrack Ltd http://www.biotrack.co.uk and Migrate Technology http://www.migratetech.co.uk/ . The cuckoo project uses Platform Transmitter Terminals (PTTs) from Microwave Telemetry http://www.microwavetelemetry.com/. These are the smallest solar-powered PTTs available and they transmit for 10 hours at a time before going into ‘sleep’ mode for 48 hours to allow the solar panel to re-charge the battery. These produce a number plotted points and, if the bird transmits while migrating, it is possible to capture the migration event in the data – it is fascinating to see migration in almost real time
See also for more information http://www.bto.org/cuckoos
We are really looking forward to getting more data from this work and co-operating with the BTO to bring you this very important information.