Birds and climate change

"Britain's climate, in common with that of the rest of Europe, is not static. On the contrary, since the end of the last ice age it has undergone a wide range of major and minor fluctuations, from the Climatic Optimum some 6,000 years ago, when the rising sea finally broke through Britain's last land connection to Continental Europe, through the early Medieval Warm Period (c. 750-1250 AD), when vineyards flourished in England, to the subsequent Little Ice Age (c. 1250-1850 AD), when frost fairs were held regularly on the frozen Thames. From about 1850 there was a climatic amelioration lasting until c. 1950, which was succeeded by a cooler spell, most pronounced in the Arctic, until c. 1980, since when it has been increasingly counteracted by the man-induced global warming of the 'greenhouse effect'." "All these climate changes, both great and small, have had a profound effect on the distributions of animals and plants in Europe, and elsewhere in the Northern Hemisphere. The greenhouse effect has further complicated ongoing colonisation by 'southern' and 'northern' bird species within Europe." "John Burton traces and explains in a readable uncomplicated way these perplexing and fasc