Materials Man

I have now stayed around Perth for 34 years, in that time the Magpie population has increased hugely where they were resident, Glasgow, Dundee etc. I used to see an odd magpie flying across the M90 motorway at Kelty 30 years ago, it is the same today. Now here’s the point, why are there no magpies in Perth making a success of town living as other populations do? I am sure people may know of an odd pair in the outskirts, but I have never seen a magpie in Perth. As a boy magpies around Eaglesham were rare country birds viewed as exotic. In Eaglesham they are now common, nesting in gardens sometimes to the chagrin of home owners and garden birds. So are they so sedentary that they only expand to large numbers in their local habitat and don’t seek to spread by geographical leaps? do we have country magpies and town magpies with the latter more successful, like foxes, on the debris of humanity?

Where is the evolutionary advantage in not spreading in geographical leaps?

I welcome comments