A dragonfly skimmed towards us, the whir of its wings like the sound of a fingernail being run back and forth across the teeth of a plastic comb. It seemed to be displaying accompanying behaviour – flying just ahead of a woman pushing a pram so as to prey on the tiny insects disturbed by the trundling wheels.
Peeling off to the left the dragonfly arced back and alighted on the edge of the sandy path near the pond. It was a male broad-bodied chaser (Libellula depressa), its fat, flattened abdomen powder blue with yellow-spotted flanks.
The dragonfly swivelled its neck, surveying its domain with oversized chocolate brown eyes that wrapped around its head like aviator sunglasses. As soon as it spotted another male invading its territory, it took off and flew out to confront the intruder.
Female dragonflies select a mate based on the quality of the oviposition site on offer. Once they find an appropriate body of water and locate the best place to lay their eggs they will copulate with whoever happens to be in the area, so males zealously defend the most desirable territories to increase the chance of mating with as many females as possible.
Having sized up the competition the resident male engaged his challenger in an aerial dogfight. There was minimal physical contact between the combatants. Instead they flew rapidly round each other, slewing left and right in ever tightening circles. Every so often they took turns to break away from the battle, zipping out and back across the water to try to demonstrate superior speed and vigour before reuniting in a blur of wings.
As we watched the duel of these broad-bodied chasers we noticed some common blue damselflies who were adopting a more laissez-faire attitude towards their rivals. Six azure blue and black-striped males perched gregariously on a row of emergent willow shoots, their parallel bodies swinging in the breeze like compass needles. Hovering above them, suitor number seven mated on the wing with a drab green female, their coupled bodies contorted into a perfect heart shape.
