Dragonflies. of Norfolk

Transcription

1 Dragonflies of Norfolk

2 Copyright Norfolk & Norwich Naturalists Society (registered charity ) Species descriptions based on: Milford PJ and Irwin AG (1990), The Dragonflies of Norfolk, Transactions of N&NNS vol 28 part 5 All photographs copyright of original authors. Bibliography Dr Pam Taylor, Dragonflies of Norfolk, Norfolk & Norwich Naturalists Society Occasional Publication no. 9 Dave Smallshire and Andy Swash, Britain s Dragonflies WILDGuides Steve Cham et al, Atlas of Dragonflies of Britain and Ireland Biological Records Centre and British Dragonfly Society (2014) Cover illustration: Banded Demoiselle (Tony Howes) Revision date Female

3 Male Banded Demoiselle Calopteryx splendens Common on some of the larger Norfolk rivers with well vegetated banks. It flies from early June to late August. Rivers with muddy bottoms are required for the larvae, and emergent or floating vegetation for the displaying males. Males have indigo wing patches and iridescent blue bodies, females have green tinted wings and metallic green bodies. Tony Howes Female John Burton

4 Emerald Damselfly Lestes sponsa Widespread in the county where there is dense emergent vegetation. It is rather a passive species remaining close to vegetation, settling frequently and rarely going far over water. It is on the wing from late June almost to the end of September. It is distinguished from Scarce Emerald by the more extensive areas of blue on the abdomen. In the male, the inner anal appendages are straight. Tony Howes Scarce Emerald Damselfly Lestes dryas Was once thought to be extinct in Britain due to habitat loss and pollution, but now known from many sites in Norfolk, particularly in the brecks. It is distinguished from Emerald Damselfly by the reduced amount of blue on the second abdominal segment, and in the male by the curved inner anal appendages. Simon Harrap

5 Southern Emerald Damselfly Lestes barbarus A migrant species whose first British record was at Winterton Dunes, Norfolk on 30 July Two further males were found a few days later. A female was present the following summer and there were further reports of migrants in subsequent years. At least five were present and breeding behaviour was observed for the first time in It is distinguished from other emerald species by the bi-coloured pterostigma on the wings of both sexes and the shape of the male anal appendages. Hans Watson Willow Emerald Damselfly Chalcolestes viridis A recent coloniser first recorded in Norfolk in 2009 at Strumpshaw Fen when a single individual was photographed. The following year up to three pairs were present in late August-September. Ovipositing into overhanging willows was observed. By 2014 there were at least three established colonies in Norfolk, including Strumpshaw, and numerous other sites where wandering individuals had been seen. It is distinguished from other emerald damselflies by the shape of the male anal appendages, the elongated spur on the side of the thorax and the pale coloured pterostigma of both sexes. Caution is needed however, as immature emeralds of other species also have pale pterostigma. Hans Watson

6 Large Red Damselfly Pyrrhosoma nymphula This is usually the first damselfly to be seen each spring. It usually appears at the end of April or in early May and lasts through the summer until the end of August. It is widespread across Norfolk and can be found in all wet habitats except fast flowing rivers and streams. David Smallshire Small Red Damselfly Ceriagrion tenellum This species is known from just one site in Norfolk. It is an acid water species which does not colonise new sites easily. It is a weak flier, rarely moving far, and settling readily. It flies from mid-june to the end of August. David Smallshire

7 Azure Damselfly Coenagrion puella This is one of the most common damselflies in Norfolk, occurring in almost any still, or slow moving body of water, and wandering away into lush meadowland or relatively dry habitats nearby. Look for the U- shaped mark on the second abdominal segment of the male. The normal form of the female has an all dark abdomen with yellow or blue segment joints. The adults fly from early to mid-may until late August. Geoff Nobes U-shaped mark on second abdominal segment. Variable Damselfly Coenagrion pulchellum This species is nationally scarce in Britain, but fairly common in Broadland. Look for the wine glass mark on the second abdominal segment of the male, and clean blue ninth segment. Overall it favours marshy dykes in meadows rather than ponds and pools. It flies from mid- May until mid-august. Wine glass mark on second abdominal segment Simon Harrap

8 Common Blue Damselfly Enallagma cyathigerum This species is abundant and widespread in Norfolk. It can be confused with the preceding species but tends to be a paler shade of blue. Look for the black circular mark on the second abdominal segment of the male, and the completely blue segments 8 and 9. Females occur in a blue form and a dull greenish buff form. The adults fly from mid-may until the end of September in good summers. Tony Howes Blue-tailed Damselfly Ischnura elegans This is the commonest and most frequently encountered damselfly in Norfolk. Able to withstand some degree of pollution, it is frequently the only species found in unsavoury areas. Males are distinctive, largely black with thin blue stripes on the thorax and blue segment eight. Females come in a variety of colour forms in which the sides of the thorax can be green, violet, olive, light brown or rose pink. It flies from mid-may until early September. Alan Dixon

9 Red-eyed Damselfly Erythromma najas This species is quite widespread in gravel pits, and pools with floating lily pads or other surface vegetation. It is larger than the average damselfly, but at a distance bears a superficial resemblance to Bluetailed Damselfly. The bright red eyes, lack of thoracic stripes, and blue on segments nine and ten of males are diagnostic. The females have green sides to the thorax and very fine, partial thoracic stripes, and a uniformly coloured abdomen. Adults appear in early to mid-may and fly until the end of August. Geoff Nobes Small Red-eyed Damselfly Erythromma viridulum This species was first recorded in the county in August 2001 at Winterton, since when it has spread to many inland sites. It is similar to Red-eyed Damselfly but is noticeably smaller with scarlet, rather than burgundy eyes. The main distinguishing marks on the male are the blue sides to abdominal segments 2 and 8 and a black x over blue on the upper surface of segment 10. Geoff Nobes

10 Male Hairy Dragonfly Brachytron pratense This is one of the earliest species on the wing, flying from the end of May to the end of June or early July. Although generally scarce in Britain, it is fairly plentiful in Broadland though very local elsewhere in Norfolk. It particularly favours dykes and carefully works its way along the vegetated margins closely following the contours, searching for insects. The apple green sides to the thorax are particularly prominent in flight. Dick Waters Female Dick Waters

11 Common Hawker Aeshna juncea This species is extremely scarce in Norfolk, occurring mainly in the east of the county, where its preferred habitat seems to be open heath or pasture with pools or dykes. Look for the golden leading edge to the wing to separate this species from the similar Migrant and Southern Hawkers. Flight period is from mid-july to the end of September. Tony Howes Migrant Hawker Aeshna mixta This species is fairly common in the county, with the resident population being reinforced by migrants from the continent. Although it may be found in a variety of habitats, it seems to favour open woodland rides and clearings. Several males can gather, showing no territorial behaviour, they fly high and hover frequently. It can be separated from the similar Common and Southern Hawkers by its smaller size and generally darker appearance. It flies from early August until mid-november provided there are no frosts. Geoff Nobes

12 Male Geoff Nobes Female Southern Hawker Aeshna cyanea Common and widespread in Norfolk, often breeding in garden ponds, but it can be found in a wide variety of habitats often away from water. It wanders far and wide, often hawking in woodland rides even after dusk. It is much larger than Migrant Hawker, and differs from both Common and Migrant Hawkers in its apple-green sides to the thorax in both males and females. It flies from late June until early October. Tony Howes

13 Brown Hawker Aeshna grandis This species is common and widespread in Norfolk from early July to late September. It flies high along the margins of well vegetated ponds, lakes and canals but wanders far from water on occasions, and several may be seen in sheltered clearings in woodland hawking for insects. It is distinguished from the rarer Norfolk Hawker by its all brown suffused wings and darker brown body. George Taylor Norfolk Hawker Aeshna isosceles This species is largely confined to the Broads, apart from isolated occurrences near the River Waveney in the east of the county. It favours clean dykes and does not move far from water. It can be distinguished from Brown Hawker by its green eyes, tan body, yellow triangle and clear wings. It is on the wing from the first week of June until as late as early August in good summers Dick Waters

14 Male Dave Mower Female Emperor Dragonfly Anax imperator This is the largest resident species in Gt Britain. It is widespread across Norfolk favouring still, sheltered waters. The characteristic long, drooping abdomen (blue in the male and greenbrown in the female) separates it from the similar Aeshna species. Males are highly territorial and each small pond or mill pool, their preferred habitats, will usually only support one male at a time. It is noticeable that males almost constantly patrol and rarely land during this stage of their life cycle. Females will land on floating vegetation to dip the tip of their abdomen into the water to lay their eggs on submerged weed (see illustration). The flight period is from early June until the end of August. Dave Mower

15 Steve Cham David Smallshire Lesser Emperor Anax parthenope Lesser Emperor was first recorded in Britain in 1996 and was once a rare migrant. The first Norfolk record was from Titchwell on the north coast in 2002, followed by an east coast record from Eccles in June In July of that year there was a report from Lound Waterworks Lake on the Norfolk - Suffolk border and this has been followed by further records from Lound in 2007 and There were three reports for the species in 2006, two of them inland, and no less than thirteen reports in 2007 from five different sites. It was in August 2007 that ovipositing pairs were observed at two sites and it is now true to say that this migrant species could be encountered anywhere in the county. Although a large hawker, it is slightly smaller than Emperor. It has green eyes and a brown thorax with greenish sides. Males have a bright blue saddle on segments 2 and 3, topped by a brown segment 1 from which the blue is separated by a yellow line. The blue on segment 3 is divided by the pointed tip of the black abdominal line. Females are duller than males. One important point to note is that while Emperor females oviposit alone, Lesser Emperors egg-lay in pairs.

16 Downy Emerald Cordulia aenea This is one of the rarest dragonflies in Norfolk, being known from only one site in north-east Norfolk, to which there is no public access. It is on the wing from the end of May to mid-july. Dick Waters Four-spotted Chaser Libellula quadrimaculata This species is widespread in Norfolk but not as common as might be expected from its status in Britain generally. It prefers still, acidic waters particularly well-vegetated and shallow pools or dykes where males will defend a territory very actively and aggressively. Males and females are similar and the four black spots on each pair of wings are diagnostic. It flies from late May until late August. Alan Dixon

17 Male Female Scarce Chaser Libellula fulva This is a nationally scarce dragonfly which has a liking for slow moving rivers with lots of cover along the banks. In Norfolk it is only found in the lower Waveney and Yare valleys. The females and young males are particularly distinctive being a beautiful tan colour with joined black triangles in the centre of the abdomen. It is on the wing from early June to late July. Geoff Nobes George Taylor Broad-bodied Chaser Libellula depressa This is an early species being on the wing from mid-may to early August. In Norfolk it is evenly spread across the county but nowhere is it common. The preferred habitat is sheltered pools or ponds with good marginal vegetation where males show aggressive territorial behaviour. It readily colonises new habitats such as gravel pits and garden ponds. Male Geoff Nobes Female George Taylor

18 Male Female Black-tailed Skimmer Orthetrum cancellatum This species is common in Broadland and widespread elsewhere in the county on gravel pits and shallow ponds and lakes. Males will defend a territory frequently returning to the same spot on the bare ground to bask. They are on the wing from mid-may until the end of August. Simon Harrap Dick Waters Keeled Skimmer Orthetrum coerulescens This species occurs at Holt Lowes and Buxton Heath, both of which provide its preferred habitat of acid bog, marshes and moorland with running water and Sphagnum pools. It is smaller than the other Skimmers and has saffron tinted wings. It flies from mid-june to the end of August, and rarely travels far from its larval habitat. Male Female Tony Howes Simon Harrap

19 Male Simon Harrap Female Common Darter Sympetrum striolatum The Common Darter is widespread and common in the county, particularly in woodland and heathland habitats, but it can be found almost anywhere. They settle frequently, and, later in the day, and more generally later in the season, they will choose warm, flat, often light coloured surfaces on which to rest. Common Darter has yellow stripes on the legs in both sexes, distinguishing it from the similar Ruddy Darter which has all black legs. Adults fly from late June and continue into mid-november if the weather is mild. David Paull

20 Red-veined Darter Sympetrum fonscolombei Red-veined Darter is a rare migrant from the continent. Look for the prominent red wing veins in the male and the deep red eyes which are bluer beneath. Ian Johnson Yellow-winged Darter Sympetrum flaveolum Yellow-winged Darter is another rare migrant from the continent, arriving from mid-july through August. Short-lived colonies can become established but rarely persist more than a couple of years. The species is similar to Common Darter but has large yellow patches on the hind wings and narrower patches halfway along the forewings. Bill Furse ARPS

21 Tony Howes Ruddy Darter Sympetrum sanguineum This species is more localised than Common Darter, but still widespread across the county. It has a preference for woodland situations. Males are not so territorial as other darters, and where found, may be in quite high densities. They are easily approached, and will fly only a short distance if disturbed, soon settling on pale surfaces on the ground or on low vegetation. Look for the deep red, waisted abdomen of the male, and the all black legs. It flies from the end of June until mid-september. Black darter Sympetrum danae This species is very scarce in Norfolk, occurring only on the acid bogs in the west of the county, particularly at Dersingham Bog and Roydon Common. It is a small species, glossy black in the male, and yellow and black in the female. It flies from early June until the end of September, sometimes later if the weather is warm. David Richmond

22 Checklist of Norfolk Dragonflies Print out this page to record your sightings of Norfolk Dragonflies. Species Where When Species Where When Banded Demoiselle Southern Hawker Emerald Damselfly Brown Hawker Scarce Emerald D fly Norfolk Hawker Southern Emerald Dfly Emperor Willow Emerald D fly Lesser Emperor Large Red Damselfly Downy Emerald Small Red Damselfly Four-spotted Chaser Azure Damselfly Scarce Chaser Variable Damselfly Broad-bodied Chaser Common Blue D fly Black-tailed Skimmer Blue-tailed Damselfly Keeled Skimmer Red-eyed D fly Common Darter Small Red-eyed D fly Red-veined Darter Hairy Dragonfly Yellow-winged Darter Common Hawker Ruddy Darter Migrant Hawker Black Darter

23 For more information on British dragonflies visit the British Dragonfly Society website at: There you will find details of the national recording scheme, and you can download recording sheets for your observations. These should be sent to Pam Taylor, the county recorder, at: