120 Barnacle geese were captured on Nonday morning on the RSPB nature reserve up at Loch Gruinart using a cannon net. The geese feed and roost in huge flocks and it is possible, but by no means easy, to lure them within range of the net by baiting the ground with corn.
Once caught, various measurements are taken, and three rings placed on the legs. One is a red ‘locality ring’ which can easily be seen with binoculars and shows that the bird was caught in a particular location (it might be a red ring for Gruinart, but a blue ring for Bowmore for example). There is also a white ‘Darvic Ring’ which can be read, with luck and skill, while using a telescope, and then there is the standard metal British Trust for Ornithology ring which can only be read by recapturing the bird, or finding it dead. So each bird captured is eventually released adorned with a fair amount of leg ornament.
The feeding behaviour patterns, population structure and breeding success of these Barnacle geese is of increasing interest to Islay’s farmers, who are compensated by the Scottish Government for the very significant damage they do to grazing on the island which would otherwise be available to livestock. The existence of the flocks also means that farmers delay the seeding of the Islay barley fields that are ‘growing for Bruichladdich’. In recent years, in common with all areas of public expenditure, the budget available for this compensation has been cut. Some of Islay’s farmers are now calling for a cull to reduce the numbers.
The cannon netting is co-ordinated by Dr Steve Percival who, with his wife Tracey, has been coming to Islay to study the flocks of wintering geese for many years.