British Dragonfly Society

Migrant Dragonfly Project

Introduction

Although many adult dragonflies remain relatively close to where they emerged, certain species may sometimes undertake long distance movements or migrations. In Britain, migration is most obvious in the occasional appearance of non-resident species, but there are also influxes of several species which also occur here as residents. Unlike the migrations of birds, and even of some lepidoptera, such dragonfly movements are however often very poorly understood, and their relevance to conservation aspects is not known.The Migrant Dragonfly Project was established in the mid 1990's as a means to improve our understanding of the details of, and reasons for, dragonfly migration. Recent results have indicated that a number of migrants also appear to be becoming commoner in Britain than earlier this century (e.g. Red-veined Darter Sympetrum fonscolombei and Lesser Emperor Anax parthenope). One less-expected spin-off from the Migrant Dragonfly Project might thus also be a better understanding of range changes which many European Odonata appear to be experiencing at present (for whatever reasons).

Migrant species to watch for

Typical migrant species to Britain include the following:

Migrant Hawker Aeshna mixta	Common Darter Sympetrum striolatum
Lesser Emperor Anax parthenope	Ruddy Darter S. sanguineum
Vagrant Emperor Hemianax ephippiger	Vagrant Darter S. vulgatum
Four-spotted Chaser Libellula quadrimaculata	Red-veined Darter S. fonscolombei
Scarlet Darter Crocothemis erythraea	Yellow-winged Darter S. flaveolum

A number of other species have turned up on a few occasions, and it is likely that further species will be added to the list in the coming years (c.f. the addition of an American species, Common Green Darner Anax junius, in the autumn of 1998.)

Submitting observations

Observers are encouraged to submit records of migrants they have seen to the Migrant Dragonfly Project. Information is urgently wanted not only on the rarer species, but also on immigration of the common species which also occur as residents in Britain. Such immigration can often be detected by sightings of either obvious directional movements, unusual numbers of individuals, or by the presence of dragonflies in atypical habitats. Records should be submitted to the Project Co-ordinator, Adrian Parr (adrian.parr@btinternet.com; 10 Orchard Way, Barrow, Bury St. Edmunds, Suffolk IP29 5BX). Special recording forms are available for those who wish to become more than casually involved; observers are kindly requested to provide written or photographic evidence to support claims of extreme rarities. Results are summarised each year in the Journal of the British Dragonfly Society.

Annual Summaries

Some of the most dramatic events in recent years are listed below.

2005: Following a poor season in 2004, it was pleasing to see some recovery in the numbers of Red veined Darters reported during 2005, though it was still not one of their best seasons. As is now typical, the largest numbers reported were from Cornwall, but there was a good spread of records. Small numbers seen for a day or two at coastal migration hotspots and occasionally inland indicate that fresh immigration took place, but at least some breeding colonies apparently also survived the species' low ebb in 2004. There was, for instance, a good series of records from the Middleton industrial Estate in Lancashire, where individuals have now been seen for 6 years in a row.

The highlight of the first half of 2005 must be the story of the Lesser Emperor. Not all the reports of this national rarity have currently been verified but the general picture is now becoming clear. Between mid June and mid July, sightings were made from roughly 10 counties as far north as Lancashire and North Yorkshire. Incredibly, up to 30 individuals were observed, though as several sites held more than one individual the number of discrete sites involved was rather fewer. There were at least two surges of records that would seem to correspond to waves of migration, and indeed a few reports of Lesser Emperors were also forthcoming from Ireland and were made at times of apparently little immigration, while others came from close to sites where the species had also been observed in 2003 or 2004. Especially as numbers seen on the near Continent were low, it is therefore possible that certain records might refer to locally bred individuals. One of the most exciting features of the season's events was that oviposition, which normally occurs while still in tandem, was observed on several occasions. Previously, well documented breeding attempts had only ever been reported from Cornwall (and here only intermittently), though breeding at Dungeness in Kent is also suspected and may easily have been overlooked elsewhere. During June/July 2005, egg laying was seen on Bodmin Moor, Cornwall, at Squabmoor Reservoir, Devon and near Knaresborough, North Yorkshire. The last record is particularly interesting, being well to the north. With the large number of records this year and the potential for local emergences in the years to come, Lesser Emperor may now be in the process of colonizing Britain. Certainly it seems able to sustain a resident population in NE Germany and Poland.
2004: Southern Emerald Damselfly was again seen at Winterton in Norfolk, fuelling speculation that the species is now established in Britain. Small Red eyed Damselfly also continued to consolidate, with a major expansion of its inland range being noted during August. Several reports were thus received from Hampshire, Cambridgeshire, Buckinghamshire and Northamptonshire, these representing the first ever sightings for these counties. There was even a record of 10 20 males seen near Rugby in Warwickshire. Coincident with this expansion, a significant fresh immigration was also noted in coastal Norfolk perhaps indicating that conditions were favourable for dispersal of Small Red eyed Damselflies over large areas of NW Europe during the summer. In addition to these records, there was a small influx of Yellow winged Darter seen along the east coast during August and early September, though numbers were low with often just isolated singles being seen, and the grand total of records being less than ten. Lesser Emperor was again reported from Dungeness, Kent, for the seventh year in a row, perhaps suggesting that it is now resident there. There were however no sightings from its other regular site at Bake Lakes in Cornwall. Perhaps the most interesting dragonfly sightings of the year relate to scarlet darters Crocothemis sp. Two mature males were seen on Guernsey in the Channel Isles on 31 July, with at least one remaining for a further three weeks. More spectacularly still, and rather a typical, an immature male was then seen in Cumbria on 30 August. A further report of a female (potentially Britain's first) from Dorset during mid September was considered inconclusive. Sight records of Crocothemis sp. in Britain are generally assigned to the European Scarlet Darter C. erythraea, a known strong migrant, though the similar Asiatic C. servilia has once been recorded as an exotic. The identity of modern British individuals perhaps needs to be examined more closely, though there seems little to suggest that the present position is incorrect.
2003: For many, 2003 will no doubt be remembered for its long, hot summer. Although indeed perhaps too hot for some, the weather proved conducive to dragonfly spotting and the year turned out to be quite an eventful one. In turns of migrants, both a good variety of species and good numbers were seen. Not too surprisingly a major theme was the continued range expansion being shown by several species, this perhaps being linked to ongoing climate change. In many ways the highlight of the year was the finding of further individuals of Southern Emerald Damselfly in SE England, following its first discovery in Norfolk during 2002. The continued appearance of the damselfly gives hope that it may soon successfully colonise Britain, much as the Small Red eyed Damselfly has recently done. This later species is now a well established feature of many sites in the coastal counties of southeast England/East Anglia and also the Isle of Wight and inland in the Bedfordshire area. During 2003 further consolidation took place, with a continued spread of sightings that included the first records from Surrey. In recent years Red veined Darter has become a regular on the British scene, with many records each year and frequent major influxes. In 2003 local emergences were reported during spring from Cornwall and E. Yorkshire (Spurn), with breeding possibly also having taken place in Lancashire. In addition to Red veined Darter, other migrant darters were also about. In particular, single individuals of Yellow-winged Darter were seen at sites in Norfolk, Suffolk and Hampshire during late July early September. These represented the first British sightings of the species for three years. One or two Black Darters were also seen in parts of eastern England well away from known breeding colonies. Intriguingly, a group of darters at Hickling Broad, Norfolk, on 29 July was found to contain a dragonfly with banded wings. Unfortunately the relatively inexperienced observer did not realise the significance of the sighting until it was too late to obtain confirmation, but from the description there is a real chance that this might have been Britain's second ever Banded Darter. In addition to the darters, another highlight of 2003 was the record number of Lesser Emperors that were seen. Almost 20 sightings from as far north as Northumberland were reported. At the now traditional site of Bake Farm in southeast Cornwall greater numbers, including some females, were however seen throughout the summer and it rather looks like these may, have included locally bred individuals.
2002: June saw large-scale arrivals of Red-veined Darter. This was the fourth substantial influx in the last 7 years, and it now appears that major movements of Red-veined Darter are occurring roughly every other year. Accompanying this immigration was at least one Scarlet Darter - the fifth British record (all since 1995) - and a male Lesser Emperor was also seen in late June. July saw a few more Lesser Emperors recorded, though it was generally a poor year for this species and the quietest since 1997. Large numbers of Migrant Hawker were on the move in parts of eastern England during August, and Small Red-eyed Damselfly continued to show well, though many records probably relate to locally-bred individuals (exuviae were discovered in Kent and on the Isle of Wight). Highlight of the year was the discovery of three male Southern Emerald Damselfly Lestes barbarus at a site in Norfolk during late July/early August, representing the first British record for this species which, like Small Red-eyed Damselfly, is known to currently be expanding its European range.
2001: There was a quiet start to the season, though one or two probably locally-bred Red-veined Darters were observed. During early July a male Southern Skimmer Orthetrum brunneum was reported from Guernsey in the Channel Isles, though anecdotal evidence suggests that the species may perhaps have first appeared there a few years previously. Late July and August then saw the arrival in southern England of a few immigrant Red-veined Darters and Lesser Emperors. Around this time major arrivals of Small Red-eyed Damselfly also took place in south-east England, with a series of dramatic records from coastal areas of Norfolk, Suffolk, Essex and Kent. There were also records well inland in Bedfordshire. At some coastal sites well over 100 individuals were noticed, and ovipositing was widespread. Small Red-eyed Damselfly appears well on its way to establishing itself in Britain.
2000: The very hot weather during mid June saw an impressive immigration of insects, with dragonflies being well represented. Red-veined Darters were recorded from several sites in England (as far north as Yorkshire), and also from Wales and Ireland. It seems likely that a few Four-spotted Chasers were on the move, and small numbers of Lesser Emperors were also reported. A male of this latter species was photographed on the island of Sanday in the Orkneys on 19 June, this apparently being the most northerly record ever for the whole of Europe! Small numbers of migrants continued to be reported during early July, but in the second half of the month a further influx of Red-veined Darters (as far north as Co. Durham) and Lesser Emperors seemed to take place in England. In southern Ireland, their first ever Lesser Emperor was also reported during late July, but more spectacularly several Emperors, including an ovipositing female, were also observed. These too are the first records for Ireland.

Although not strictly "migrants" any more, Small Red-eyed Damselflies reappeared at their Essex site in 2000, and in addition several were discovered at a new locality on the south coast of England during early August. The colonisation of Britain by this species seems to be well under way.
1999: This was relatively quiet in terms of the volume of migration, but a number of dramatic events were none the less reported. Lesser Emperor continued its good showing, with a dozen records including a pair seen ovipositing. Most excitingly, exuviae were also noted at two sites in Cornwall, representing the first confirmed successful breeding of the species in Britain. The other main migrant species to show up in numbers was Yellow-winged Darter, with an influx during August. In all about 60 individuals were seen - these being accompanied by small numbers of other Darters, most notably Black Darter. Two other outstanding events took place in 1999. The first ever British records of Small Red-eyed Damselfly Erythromma viridulum were made in Essex. Numbers seen suggested an established colony, though individuals must have originally been derived from Continental stock. Even more dramatically, in early September a female Blue Dasher Pachydiplax longipennis was found on an oil-rig in the North Sea off Shetland. This common North American dragonfly had never before been recorded from Europe. Although the evidence favours it being a true vagrant, the possibility of an accidental introduction could not, however, be completely ruled out.
1998: Influx of dragonflies during January - March, many probably Vagrant Emperor H. ephippiger. Continued arrivals of Red-veined Darter S. fonscolombei (many staying to breed) and Lesser Emperor A. parthenope. Common Green Darner A. junius blown over from North America to Cornwall and the Scilly Isles by the remnants of Hurricane Earl.
1997: Further arrivals of Red-veined Darter S. fonscolombei and Lesser Emperor A. parthenope. Large influx of the commoner Darters Sympetrum spp. on the east coast.
1996: Major influx of Red-veined Darter S. fonscolombei, with some breeding colonies established. First confirmed British record of Lesser Emperor A. parthenope.