The influence of climate warming on phenology.

Phenology, the study of timings of natural events, is the longest written biological record in the UK. It has thus proved invaluable in revealing how species have responded to recent climate warming. I have played a major role in achieving Scientific 'legitimacy' for the subject and there is a growing urgency to demonstrate climate induced effects to both a scientific and a general audience. My phenological publications fall into four broad areas. 1 . Utilising historic data. Many historic data sets have languished in obscurity for >50 years. Identification and examination of some of these data has revealed how biological events responded to past fluctuations in temperature. The typical response of c.6 days earlier for each 1°C warming has enabled a prediction of response to future climate. National data sets have given greater confidence in these results. 2. Bird phenology. Bird data, particularly that on migration timing, forms a huge resource of phenological material. I have examined the role of temperature in bird phenology and on migration patterns from various sources of data and have begun to extend these studies through international collaboration (two further papers 'in press'). In general, the response of birds is more variable and not as great as that of plants and invertebrates. 3. Other taxa. Post-war changes have already taken place in the timing of a wide range of taxa. In some instances events are at least three weeks earlier. These results have encouraged me to resurrect a phenology network after a 50-year break (www.phenology.org.uk). 4. Increasing awareness. Changes in phenology are readily understood by various sectors of the public and are a good vehicle with which to demonstrate climate change. The UK Government has now accepted phenological events as Climate Change Indicators.