There is an amazing amount of information that can be learned from ringing and at this time of year migration strategies are high on the list. Projects can be done looking at fat deposition or even the timings and reasons for movement.
Saying that, you can never be 100% sure what you will catch. While doing a routine ringing session, Maple Cross Ringing Group had a very unusual bird appear in their net. This was an Eastern Crowned Warbler, the second to be seen in Britain! It wasn't at a migration hotspot like Fair Isle, Shetland or somewhere in Norfolk but a private site at Hilfield Park Reservoir, Hertfordshire!
This bird breeds from eastern Siberia through to south-eastern China, Korea and Japan, and winters in south-east Asia south to Indonesia, so is around 11,500km off course. Birds that have been seen in Europe generally don't stay in the same location for very long and this bird was no exception, not being seen again after its release. It will be very interesting to see if this ringed juvenile Eastern Crowned Warbler is located anywhere else in the near future.
Thanks to Mike Beatley for the photos