The use by Bearded Tits of the grit trays at Leighton Moss have been exciting a lot of interest this year. I thought some back ground information on the development of the trays may be of interest along with our findings from colour ringing the birds.
For many year Bearded Tits used to grit on the gravel paths. The rather poor photo shows a shot taken c 1993 with 22 bearded tits all gritting on the paths. In c 1996 I had the idea to provide grit trays and they have been used ever since and use of the paths has stopped. Birds gritting on the path were subject to a lot of disturbance but the present arrangement allows lots of people to see (and photograph) these super birds.
Bearded Tits need grit at this time of year because they are changing from the soft insect diet of summer to the harder mainly reed seed diet of winter. The grit sits in the gizzard and so grinds up the seeds.
We are also responsible for the colour rings you can see on all but a few birds. The birds are colour ringed as part of a long term (25 years) population and DNA study of this very local species. Remember Leighton Moss is the only place you can regularly see this evocative species in the North West.
The colour rings have also enabled us to study their gritting habits. Every year the adult birds come first to the trays from about mid September to mid October almost all the birds gritting are adults but as the season progresses birds of the year move in. This year to date we have identified 51 different birds using the trays 23 of them adults and 28 this year's young ones. So far this year we have ringed 104 young bearded tits the largest number since 2000 so many more may yet visit the trays.