When looking at the history of geese you may start around 4500 years ago with the Geese of Medum now in the Cairo Museum. Not only does it tell us of the species found in Egypt at that time but the effects of migration due to 'global cooling' with the effect of the last ice sheet! These species now winter much further north due to 'global warming'!
Sophie it is not entirely true that the re established Greylag population is as sedentary as you suggest birds moult migrate from North Yorkshire to lake Windemere to moult and others go as far as Loch Leven to moult again from at least as far south as North Yorkshire. When I was involved radio tracking and satellite tracking greylags to look at pesticide risk they were in fact exceedingly mobile despite the fact that they can be city park birds one day and miles away the next.
When looking at the history of geese you may start around 4500 years ago with the Geese of Medum now in the Cairo Museum. Not only does it tell us of the species found in Egypt at that time but the effects of migration due to 'global cooling' with the effect of the last ice sheet! These species now winter much further north due to 'global warming'!
Sophie it is not entirely true that the re established Greylag population is as sedentary as you suggest birds moult migrate from North Yorkshire to lake Windemere to moult and others go as far as Loch Leven to moult again from at least as far south as North Yorkshire. When I was involved radio tracking and satellite tracking greylags to look at pesticide risk they were in fact exceedingly mobile despite the fact that they can be city park birds one day and miles away the next.