They were both females and came separately but both stopped some time on the trays. Both were colour ringed so we know their history.
X439755 was ringed as a juvenile on 10/7/09. It was not recorded on the grit trays in 2009. But in 2010 it was recorded gritting on 21 days between 27/9 and 11/12. In 2011 it visited the trays on 22 days between 3/10 and 19/11.
L714677 was ringed as a juvenile on 2/7/11. It was recorded gritting on a record 24 days between20/9 and 24/11.
These two birds were the most regular visitors to the grit trays in 2011 so it will be interested to see if they follow the same pattern this year. Most birds are recorded on under ten days throughout the gritting season from late September to mid December.
Bearded Tits need grit at this time of year because they are changing their diet from soft insect food of spring and summer to the much harder reed seed diet of autumn and winter. Some idea of the numbers of small stones that they ingest is given by a German study when the contents of 12 gizzards averaged 609 stones.
The grit trays are positioned in the first bay on the right as you go down the Public Causeway. This year the reserve has a camera on the trays so you can also sit in comfort in the tea room and watch proceedings!
John
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