The thaw is quickly underway but there is still thick snow over the garden. I look out and there is a couple of Collared Doves resting on the apple tree. One of them, after carefully looking around jumps to the bird table to eat. The Collared Dove is a classic example of a species undergoing a range expansion. Although this expansion was achieved naturally, availability of grain due to agriculture undoubtedly played a role in facilitating it and in this species is strongly associated to cities, towns and agricultural land, and can be considered a human commensal species. Its original range was apparently India; by the sixteenth century it had reached Turkey and then, during the twentieth century, a rapid European invasion took place up to the point that now it has virtually colonized available areas over the whole continent. It is nowadays such a common urban bird that it is hard to believe that in the UK, the Collared Dove was first recorded breeding in Norfolk in 1955 (according to the British Trust for Ornithology the population estimate is over half a million pairs).