Female dragonflies fake death to avoid unwanted mating


This video from England says about itself:

Common Hawker Dragonfly (Aeshna juncea)

13 February 2015

Common Hawker Dragonfly, filmed in the New Forest, Hampshire, UK. One of the rarest species in the New Forest, occurring only sporadically in a few isolated locations. Video includes male and female of the species, plus a mating pair.

From New Scientist:

27 April 2017

Female dragonflies fake sudden death to avoid male advances

By Sandrine Ceurstemont

Female dragonflies use an extreme tactic to get rid of unwanted suitors: they drop out the sky and then pretend to be dead.

Rassim Khelifa from the University of Zurich, Switzerland, witnessed the behaviour for the first time in the moorland hawker dragonfly (Aeshna juncea). While collecting their larvae in the Swiss Alps, he watched a female crash-dive to the ground while being pursued by a male.

The female then lay motionless on her back. Her suitor soon flew away, and the female took off once the coast was clear.

“I was surprised,” says Khelifa, who had never previously seen this in 10 years of studying dragonflies.

Female moorland hawkers are vulnerable to harassment when they lay their eggs since, unlike some other dragonflies, they aren’t guarded by their male mates. A single sexual encounter with another male is enough to fertilise all eggs and copulating again could damage their reproductive tract.

Khelifa found that the females often retreat to dense vegetation near ponds at this time, probably to hide. And they often act dramatically when they emerge.

High-speed plunge

He observed 27 out of 31 females plummeting and playing dead to avoid males, with 21 of these ploys successful. Plunging at high speed is risky though, and according to Adolfo Cordero-Rivera at the University of Vigo in Spain, it may be a strategy that they use only in areas with lots of dragonflies. “Females may only behave in this way if male harassment is intense,” he says.

Few animals have been caught feigning death to trick suitors. The behaviour has been seen in a species of spider (the males use it to improve their chances of mating), two species of robber fly and a type of mantis.

Playing dead to avoid predators, however, is more common and has been observed in dragonflies. “It’s likely that females expanded its use to overcome male coercion,” says Khelifa.

Khelifa is interested in finding out whether the behaviour is unique to species that lay eggs alone or whether it is more widespread. Using extreme tactics to resolve sexual conflict isn’t unique to moorland hawkers: in their damselfly relatives, for example, females eat their partner.

New dragonfly species named after baby Bhutanese prince


Gyalsey emerald spreadwing dragonfly

This month, Naturalis Biodiversity Center in the Netherlands reports that a new dragonfly species from Bhutan has been named.

The insect was discovered in 2015, during a joint Bhutanese-Dutch expedition in eastern Bhutan.

Its name is Gyalsey emerald spreadwing dragonfly. Gyalsey means ‘prince’ in Bhutanese. The new species was named after the young crown prince of Bhutan; on his first birthday, the dragonfly’s name became known.

113 dragonfly species are known from Bhutan.

Birds and dragonflies in Germany


This video shows a sea eagle, and a mute swan, on Rügen island in the Baltic sea in north-east Germany.

On 4 October 2016, we were supposed to be on Rügen.

However, a storm which caused flooding meant we could not sail on the sea, but had to stay in the interior near Kamp village.

After seeing the cranes and the rest of our early morning walk, we started a longer walk.

Songbirds are migrating to the south this month. We see scores of goldfinches.

Kamp, 4 October 2016

We walk on an old railway track. In Adolf Hitler’s days, trains here went to Peenemünde V2 missile base. After the war, the rails were removed, and a footpath remained.

Great cormorants on 4 October 2016

Many great cormorants sitting in leafless trees. And hundreds of them fishing together in the water.

An edible frog jumps.

A meadow pipit flies.

Emperor dragonfly male, Germany, 4 October 2016

In the bushes, various dragonflies rest. Like this male emperor dragonfly.

Sympetrum dragonfly, 4 October 2016

And also smaller species. I think this is a male Sympetrum dragonfly. I am not sure which species, as quite some related species look rather similar.

Dragonfly, 4 October 2016

And of this small dragonfly I am not even sure which genus it is.

We pass some cranes which stayed in this wetland after most others flew away to feed on fields.

Beavers live there, as trees with obvious traces of gnawing show.

Great cormorant nests, Germany, 4 October 2016

We pass great cormorant nests. They are empty now; the young birds have fledged.

Birch trees, 4 October 2016

Birch trees. A great spotted woodpecker flies to one of them.

On another tree, a nuthatch.

A flock of barnacle geese.

Shoveler ducks.

Wetland near Kamp, 4 October 2016

A water vole crosses the footpath.

Wetland near Kamp on 4 October 2016

We arrive back on the road. Not many cars, but still they are dangerous for the many caterpillars crossing. They are pale tussock caterpillars. The Dutch name for this species is meriansborstel, Merian’s brush; named after famous seventeenth century naturalist and painter of insects Maria Sibylla Merian.

We arrive back in Kamp.

At 18:05, to the cranes again. Many arrive for sleeping; including juveniles. Behind them, barnacle geese.

Black-bellied plovers in winter plumage.

Dunlin.

A juvenile Caspian tern cleanses its feathers.

At 18:30, 670 cranes have arrived for sleeping.

Gadwall ducks land on the water.

Dragonflies, damselflies in the Low Countries


This 1 October 2016 video from the Netherlands shows a willow emerald damselfly; using its legs to remove spider’s threads.

This 2 October 2016 video from the Netherlands shows a common darter dragonfly eating.

This 16 October 2016 video from Belgium shows a southern hawker dragonfly.

Higher temperatures could trigger an uptick in damselfly cannibalism: here.

Dragonfly couple escapes from death


In this video, a dragonfly couple, after mating, still hold on to each other until the female will have deposited her eggs under water.

An edible frog tries to eat them, but just misses.

Geertje in the Netherlands made this 6 September 2016 video.

Dragonflies wake up in the morning


This 24 August 2016 video shows banded darter dragonflies waking up in the morning in the Netherlands.

Young emperor dragonfly emerges, video


This video from Britain says about itself:

An emperor dragonfly emerging

22 July 2016

Footage of an emperor dragonfly nymph emerging from its exuvia (shell) as an adult and laying its eggs in water.