a period of climatic warming since 1963 has seen the uk population increase to "more than 2,500 pairs in 2006 (wotton et al. 2009). expansion into patches of structurally suitable habitat (up to an altitude of 400m), more northerly areas and away from the core of the range, from dorset and hampshire to derbyshire and suffolk, is likely to have been facilitated by milder winter weather (wotton et al. 2009, bradbury et al. 2011)... the dartford warbler population in the uk is expected to continue to increase. however, future climate-based projections for the european range indicate that by 2080, more than 60% of the current european range may no longer be suitable (huntley et al 2007). there is evidence that this is happening already, with severe declines in spain and france (green 2017). for this reason, the species is classified as near threatened on the iucn global red list. if the declines in southern europe continue, the uk will become increasingly important for global conservation of this species".