A field guide to dragonflies and damselflies

Wetland insects worth learning

Few sights say "high summer" quite like a dragonfly patrolling a pond edge. Yet for many of us the identification stops there. Big, fast, blue or brown — and gone before we have focused properly. The good news is that you do not need a net, a microscope or years of experience to get most of the way. Our 30-odd regular breeding species are distinctive, and much of that distinction is visible with the naked eye, provided you know what the insect does with its wings when it sits still.

Dragonflies and damselflies are not finicky about their resting spots. They perch on reed stems, fence posts, lily pads, gravestones and even bicycle handlebars. Get into the habit of checking where and how they hold their wings, and your identification rate will jump sharply.

The resting posture is your first clue

Both groups belong to the order Odonata, but they split into two very different habits. Learn this and you can sort almost every insect you meet into one half of the field guide at a glance.

• Dragonflies (Anisoptera) are stockier insects with broad-based, powerful wings. When they perch, they typically hold their wings out flat and open, like a glider at rest — and they are generally strong fliers, frequently leaving a perch to hunt or chase rivals.
• Damselflies (Zygoptera) are slender, needle-bodied insects with a slow, fluttering flight. Most hold their wings folded along or above the abdomen when perched, so the insect reads as a thin line rather than a cross.

There are exceptions, and they are useful ones. The two demoiselles — Banded and Beautiful — are damselflies that hold their wings wide open like a dragonfly, but their bodies are still slim and their flight floppy and dark. Emerald damselflies perch with wings held half open at roughly 45 degrees, a give-away if you are used to them being shut. And a male Emerald or a mature male Beautiful Demoiselle will shift positions with the temperature, opening up as it warms.

Dragonflies to look for

Start with the big showy ones on days above about 18°C, when insects bask and hold a perch for long stretches. Hawkers — Southern, Migrant and Brown — are powerful aerialists that hunt high or along hedgerows and often hover while you fumble for a phone. Southern Hawkers are curious and will sometimes hang almost still a metre from your face.

• Emperor Dragonfly: the biggest of the lot, with a green-blue body and a habit of patrolling open water constantly rather than perching. Females are green. Watch for the dipping egg-laying flight.
• Four-spotted Chaser: a dark base to each wing, easy to confuse with nothing else on a heathland pool.
• Common Darter: the small orange-red one that lands on anything, including your hand, and returns to the same perch after each sally.
• Black-tailed Skimmer: blue-grey abdomen with a black tip, typically perching flat on bare gravel or sandy banks rather than on vegetation.

Damselflies and their exceptions

Damselflies repay patience. Sit still beside a pond margin for ten minutes in June and you will see them settle. Look for the folded wings forming a narrow line above the back — from the side this looks like a closed pair of scissors. Blue species are the tricky ones: Azures, Common Blues and Variable Damselflies all look similar from a distance, so check the pattern on the second abdominal segment, which needs close focus or binoculars.

• Large Red Damselfly: first out in spring, red and black, often in garden ponds from April.
• Blue-tailed Damselfly: a black body with a single blue segment near the tail tip, unmistakable.
• Banded Demoiselle: males deep metallic blue with dark blotched wings, females green with a bronze sheen, fluttering along slow rivers and canals.
• Willow Emerald: a late-season species that lays eggs in overhanging willow and alder branches above water — check the undersides of leaves and twigs.

How to watch without disturbing

Approach obliquely, never straight on, and keep your shadow off the water where possible. Dragonflies react to movement rather than size, so slow, steady steps work better than freezing entirely. Early morning is underrated: insects are cool, sluggish and perched low, often on rush stems a few inches above the surface, and they will sit for photographs while they warm up. Warm afternoon periods are best for seeing behaviour — territorial flights, tandem pairs and egg-laying in tandem, when the male remains attached while the female dips her abdomen into the water or plants.

Binoculars designed for close focus, ideally down to about two metres, are more useful than a long lens. A notebook with dates, site names and weather notes is worth more than any gadget; recording is how you learn a site's timing instead of guessing at it.

Conservation: small wetlands, big returns

Dragonflies are among the better news stories in UK conservation. Cleaner rivers and canals, the restoration of gravel pits, the digging of farm ponds and the rewetting of lowland peat have allowed several species to expand, and warmer summers have helped southern species such as the Small Red-eyed Damselfly and Willow Emerald shift northwards.

The picture is not uniformly cheerful, however. Many species depend on very particular conditions: bare, sunny margins for egg-laying, unpolluted water with good oxygen levels, and the mosaic of open water, reedbed, fen and wet woodland that a healthy wetland provides. Nutrient enrichment from farmland runoff, abstraction lowering water tables, and ponds that become overgrown when grazing or cutting stops are all serious pressures on the more specialised species.

Practical conservation works. Ditches cleaned on rotation rather than all at once, hedgerows left to shade part of a stream while leaving sunny stretches, and networks of small ponds within a few hundred metres of each other all help populations survive a bad year. If you own or manage any wet corner, leave a few metres of bare bank exposed and resist the urge to tidy every reed. Then record what arrives. Recording schemes and county recorders rely on volunteers, and the data they gather genuinely shapes where habitat work is prioritised. Your afternoon by the water is more useful than it looks.