Abstract
The history of recording and monitoring of Odonata in Britain is briefly described. Results are then presented which suggest that the country’s Odonata fauna is currently in a period of flux, in a manner consistent with the actions of a high-level regulatory factor such as climate change. The ranges of many resident species are shifting. Leucorrhinia dubia has recently been lost from southern England, but many species are presently expanding their ranges to the north and west, some (such as Aeshna mixta and Anax imperator) with considerable speed. In addition to these changes, a number of ‘southern’ species have started to appear in Britain for the very first time. These include Lestes barbarus, Erythromma viridulum (which has now become a locally-common resident in southeast England), Anax parthenope and Crocothemis erythraea. In addition to these distributional changes, some recent trends in flight times are also discussed. Evidence indicates that many species are now emerging significantly earlier than in the past, though trends relating to the end of the flight period are less clear cut.