Tracking Greenshanks
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A colour-ringed and geolocator-tagged Greenshank |
This year, 2013, we (Me, Nick Christian, Brian Etheridge and Ron Summers) caught several Greenshank and marked them with individual colour ring combinations. The orange ring on each also held a tiny, less than 1 gram, geolocator. The Greenshank weighed about 200 gm. This is a device which can determine the birds' approximate location to within 100 km, by analysing the relative daylight length with Greenwich Mean Time. The information on where they have been is stored in the device's memory and downloaded on subsequent recapture of the birds.
We retrieved two geolocators which had been put on birds last year. And the preliminary results suggest that Greenshank which breed in northern Scotland over-winter in southern England, Wales and Ireland.