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FUTURE RECORDING
The species maps presented in this Atlas portray the
broad patterns of Odonata distribution in Britain
and, to a lesser extent, in Ireland. In the latter
country, there is still much recording to be done
before comprehensive maps can be produced,
although the position has improved remarkably in
the past decade. There is little doubt that basic
recording will continue to fill in the distribution
patterns of the commoner species in parts of Britain,
and to identify some new sites for scarcer species
(see also the section on Future distribution maps
in the Fieldwork and data management chapter).
The distribution of species is seldom static, and
continued recording throughout the landscape will
be needed to detect and monitor the changes which
are taking place (Eversham 1994). Some species,
such as Aeshna mixta, have attracted considerable
attention in the context of possible climatic change
(Watt, Ward & Eversham 1990). The example of A.
mixta also stresses a recpirement of future recording
which is already being addressed for other reasons:
the need to establish proof of breeding. Highly
mobile species such as A. mixta can occur as adults
tens or hundreds of miles away from breeding sites.
However, there is clear evidence that the present
range expansion of A. mixta is an extension of
breeding range, and not merely an increase in
northward mobility (or even a higher level of
detection of such mobility by recorders). It has
been observed emerging from ponds in
Derbyshire, Nottinghamshire and Yorkshire.
Proof of breeding became a focus for recording in
1988, with the launch of the Odonata Key Sites
Project (KSP) (Merritt 1988). This is primarily an
initiative in support of conservation. Although the
broad patterns of distribution of each species were
well known, as were the locations of many of the
more important breeding sites for scarcer species,
it was not possible to evaluate fully these sites
relative to others owing to the lack of comprehensive
breeding data. The new recording card, the RA70
(Figure 12), provides space for information on each
stage of the life cycle. The approach has already
been used successfully at a county level, in the
Cheshire dragonfly survey (Gabb & Kitching 1992).
The authors have distinguished between proven,
probable and possible breeding records. This
distinction is of great importance, especially in
relation to nature conservation, and it is hoped that
county surveys in the future will follow their
example.
The RA70 also encourages recorders to estimate the
abundance of each species. Even an approximate
indication of numbers present is an improvement on
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previous recording methods, and, taken over several
years, KSP data are beginning to show which sites
support significant populations of scarce species.
No less valuable, it is becoming apparent which
sites have unusually rich breeding assemblages
(rather than merely having a long species list due to
diligent observers noting species in transit). Given
the continued support of recorders, the role of
dragonflies in site assessment for nature
conservation (Nature Conservancy Council 1989)
can only increase.
Two other areas of enhancement in recording also
seem likely to play an important part in future: the
recording of immigrant species and movement by
resident Odonata, and the thorough monitoring of
individual sites.
Migrant butterflies such as the painted lady (Cynthia
cardui) or the clouded yellow (Colias croceus) occur
annually, and their occasional abundance attracts
considerable attention. Similar movements among
Odonata seem to be rarely detected. This may be
because, unlike butterflies, the species of dragonfly
most often involved are British/lrish resident
species. The phenomenon is most obvious in the
occasional arrival of species not normally present,
such as Hemianax ephippiger or Sympetrum
fonscolombii, records of which often find their way
into the literature.
Movement of resident species is much more difficult
to evaluate, but any species which is able to
colonise new habitats must pass through the
unsuitable countryside in between: if resident
species are observed in apparently unsuitable sites,
or occur only for a few days and are not breeding,
they are almost certainly wanderers. The appearance
of S. danae away from heathland pools and
acid peatlands may represent such long-distance
movement. A scatter of recent records of Ischnura
pumilio away from established breeding sites, and
an observation of numerous post-emergent
individuals flying almost vertically up-wards on
warm days suggests the possibility that I. pumilio
may be a 'wandering opportunist' (Fox 1989).
Occasionally, dragonflies are seen flying in from the
sea, sometimes in large numbers (Longfield 1948).
Observers who spend all day in one place may see
a steady stream of dragonflies pass them, flying
along a river or over open countryside, perhaps all
moving in the same direction. These may be rather
rare events, but, if all observers are on the look-out,
they may add up to a clearer picture of mobility
within resident species. To this end, a recording
form was drafted in 1991, and a revised version, the
RA74 (Figure 13), was introduced in 1992.