More than any other species of hawker, A. mixta is found in large aggregations (e.g.
19+ seen hawking by a hedge on the Dengie peninsula by T. Tarpey, 18.8.1985). These
large concentrations of individuals may be arriving immigrants, but even at breeding
sites and on nearby feeding grounds, individuals appear to be communal in habit, and
there is little evidence of any territorial behaviour. When hawking for food, A. mixta
frequently flies very high indeed over ponds (not necessarily breeding sites) and
woodland clearings or rides. Sunny rides in conifer plantations are among the best
places to observe this species. Here they hawk for insects and frequently settle to 'bask'
in autumnal sunshine, sometimes several close together on a favoured branch or tree-
trunk. The species is sometimes on the wing from the beginning of August, but is not
usually seen in numbers until the latter half of that month. It is usually (along with
Sympetrum striolatum) one of the latest species to be seen, continuing to fly until the last
week in October in favourable years.
Aeshna mixta is one of the few species currently extending its range in the British Isles.
It was formerly considered to be only an immigrant from the continent but is now
established as a breeding species, with a predominantly southern and eastern
distribution. However, its range within the British Isles is continuing to extend in both
westerly and northerly directions, as confirmed by numerous local surveys (see, for
example, Coker and Fox, 1985, p.70; Parker and Holliday, 1979, 4.9; Kemp, 1981, p.19;
and Holland, 1983). S. Holland's comments, in particular, indicate a rapid increase in
breeding populations of the species in Gloucestershire between 1973 and 1982.
The first reference to the species in Essex is in J. F. Stephens (1835-7), and the locality
given is Epping. W. F. Evans (1845) repeated Stephens' record, but it did not figure in E.
Doubleday's (1835) list. H. Doubleday (1871) included it as a Forest species, but his
record is almost certainly erroneous (see Appendix B). W. J. Lucas, in his notes in the
Entomologist on the dragonfly season of 1899 (1900a), mentioned reports of A. mixta in
the Colchester area from W. H. Harwood, the species having been scarcer than in the
previous year. Lucas (1901) commented on the comparative abundance of this 'usually
scarce' species in the 1900 season, mentioning sightings at Pitsea (H. J. Turner) and
Loughton (F. M. B. Carr). Harwood himself (1903) commented that the species was
considered 'rare and local', but 'during the past two years has extended its range and
appeared in larger numbers'. He continued: 'It is now well distributed in the Colchester
district and as all the inland examples seem to be mature, while the majority of those
found on the coast are immature, this may afford a clue to a fuller knowledge of its
earlier stages than we at present possess'. Possibly Harwood was suggesting that the
breeding sites for A. mixta were then mainly coastal.
The species was observed sporadically in Epping Forest by the Campion brothers
(1902 and 1906), but does not appear on E. E. Syms' (1929) list for the Forest. E. B.
Pinniger (1933) reported Doubleday's and the Campions' records only, and clearly
regarded the status of A. mixta as puzzling. In a note devoted to this species (Pinniger,
1934a) he reported several searches for the species in 1933 which 'failed to produce any
definite evidence'. The species did finally turn up in Pinniger's lists for 1935 ('the first
record there for some years') and for 1936 (Pinniger, 1936 and 1937), and was reported as
having been common in the Forest in 1937 (Pinniger, 1938). Interestingly, A. mixta first
appeared in C. O. Hammond's unpublished notes for the Forest in 1937.
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