Adaptation of Orkney's greylag geese
Alan Leitch, Orkney Reserves Site Manager, talks about how climate change has affected greylag geese.
The changes in greylag geese
"In the early 1980s, greylag geese were quite scarce visitors to Orkney.
The autumn migration saw flocks passing over the islands on their way south from their Icelandic breeding grounds to wintering grounds much further south in Scotland, for example in Perthshire and Aberdeenshire. Only some 500 or so stayed over the whole winter and this remained the picture throughout most of that decade.
On the up
Numbers began to rise in the early 1990s. The figure had risen to 5,000 by 1992, to more than 20,000 by the turn of the millennium and to more than 30,000 by 2002. Numbers just continue to go up and up and the latest census in December 2006 produced the amazing total of 67,540, probably almost two-thirds of all the greylags known to be in the Icelandic population.
Geese now seem to be everywhere in Orkney! It would be difficult to drive for more than a mile anywhere in the islands without coming across a flock. Why has this happened? Are there simply more geese in Iceland than there used to be? Apparently not.
The Icelandic population seems to have been relatively stable or even declining as a result of heavy shooting pressure there. The answer appears to be that a greater proportion of the population is stopping in Orkney rather than going on further south like they used to."
A full larder
"Why should this remarkable change in habits have taken place? It is thought that with ever-warmer winter weather, and therefore no cessation in the growth of grass in the islands, the geese can now readily find food here throughout the winter and don’t have to press on further south.
Why fly on an extra two or three hundred miles when the larder is available closer to home?
Good for the geese, but problems for at least some Orkney farmers who find that some of their best grazing ground can be affected by these extraordinary numbers."
Alan Leitch is a warden of our Orkney reserves.