Aeshna caerulea. Records in England and Wales are dubious. Evidence of some range contraction in central Highlands and range expansion in western Highlands, but this could reflect differences in recorder effort.
Red squares denote 1975-90 records and overlay all other records. Presence of red squares implies stable populations.
Orange squares denote 1700-1974 records and are overlain by any records from 1991-2005. Presence of orange squares implies range contraction, usually as a result of habitat degradation.
Yellow squares denote new locality records from 1991-2006. Presence of yellow squares implies range expansion. A response to climate change would typically be indicated by a preponderance of yellow squares at the northern or western edge of the range. A response to water quality improvements in riverine species is likely to be indicated by linear expansion of yellow squares or intra-range infilling.
Post-1990 records from Ireland are not available at the time of writing (except A. mixta, A. cyanea, A. imperator and S. fonscolombii).
The maps are derived from the NBN Gateway and are reproduced with permission, and are arranged in alphabetical order of genus and species.
Aeshna caerulea. Records in England and Wales are dubious. Evidence of some range contraction in central Highlands and range expansion in western Highlands, but this could reflect differences in recorder effort.
A. cyanea. Evidence for recent range expansion in northern England and Scotland which may be in response to climate change.
A. isosceles. Range contraction in eastern fens. Some evidence for recent expansion into Suffolk and Lincolnshire.
A. mixta. Evidence for recent westward and northward range expansion which may be in response to climate change.
Anax ephippiger. There are surprisingly few post-1991 records of this species considering the increase in the number of records of other migrant species over this period.
A. imperator. Evidence for recent northward range expansion which may be in response to climate change.
Brachytron pratense. Evidence for pre-1974 range contraction in eastern English Midlands, but there is now an apparent reversal in this trend and recent records suggest the species is recolonising this area, possibly as a result of improvements in water quality.
Cordulia aenea. The species appears to have been lost from several localities prior to 1974 but this trend appears to have been balanced to some extent by some recent records from new localities.
C. mercuriale. Some evidence for pre-1974 range contraction. Recent records from new localities in Devon. Recent survey work suggests the species has been lost from west Wales and from some sites in the New Forest, and is declining in the Gower Peninsula (see p.300).
C. puella. Possible recent range expansion in Scotland, although this may reflect changes in recorder effort.
Calopteryx splendens. Evidence for recent northward range expansion, which may be in response to climate change, but recent records from throughout its range may be in response to improvements in water quality.
C. virgo. Evidence for pre-1974 range contraction especially in eastern England; some indication of expansion throughout range possibly in response to improvements in water quality and river management.
Ceriagrion tenellum. Evidence for pre-1974 range contraction especially in the eastern part of the species range.
Enallagma cyathigerum. Population appears
stable. Recent records, especially those from Scotland, probably reflect changes in recorder effort.
E. viridulum. In this map red squares denote records from 1999-2001, orange squares are new locality records from 2002-3 and yellow squares denote new locality records from 2004-6. The species appears to be rapidly colonising England and spreading westwards from its original points of entry.
I. pumilio. The species appears to have suffered a pre-1974 range contraction in eastern England, but other sites appear to have been colonised more recently. This probably reflects the ruderal habits of this species.
L. dryas. Evidence for a serious pre-1974 range contraction from which the population has not recovered except perhaps in northern Norfolk.
L. sponsa. Large increase in the number of localities that the species has been recorded in since 1991, especially in southern Scotland.
Libellula depressa. The species appears to have been expanding its range northwards in recent years which may be in response to climate change.
L. fulva. Increase in post-1991 records from new localities may be in response to improvements in water quality; however, the species has not recolonised sites in the Norfolk Broads from which it was recorded before 1974.
L. quadrimaculata. There seems to have been a considerable increase in the number of localities that this species has been recorded in since 1991, especially in Scotland and eastern and central England.
Leucorrhinia dubia. Southern edge of species range may be contracting northwards, possibly in response to climate change. New records from Scotland may reflect changes in recorder effort.
Orthetrum cancellatum. Evidence for a northwards and westwards range expansion consistent with a response to climate change.
O. coerulescens. In most parts of its range the population appears stable, but there is evidence for expansion in the Somerset Levels and Norfolk Broads, possibly in response to improvements in habitat quality.
Platycnemis pennipes. Recent increase in localities, probably in response to improvements in water quality.
Somatochlora arctica. Apparent recent increase in localities may reflect changes in recorder effort.
S. metallica. Population apparently stable, except in southwest Scotland where local expansion apparent.
Sympetrum danae. Recent new records in coastal localities in southern and eastern England may be as a result of migrants arriving from continental Europe.
S. flaveolum. Large recent increase in sightings probably in response to climate change (migratory species).
S. fonscolombii. Large recent increase in sightings probably in response to climate change (migratory species).
S. sanguineum. Recent increase in northern and western records probably reflects response to climate change.
