Thursday, 13 June 2013

Frog The Dragon Slayer

Common Blue Damselflies courting
Two pairs of Damselflies gripped in courtship

It's all been happening at the kitchen garden pond this week. Damselflies are already busy courting, in the pictures you can see the tip of the blue male's abdomen attached to the neck of the female, this is the prelude to mating.

In the video clip below you can see the two males having a brief chat whilst the females below do the same.

After watching the damsels for a while I became aware of something else in distress. A mature dragonfly nymph had crawled up the wall of the pond with a grotesque appendage...

Dragonfly nymph climbs out of the pond to escape attacker

Another dragonfly nymph had firmly attached himself to the escapee, his jaws clamped to where the wings should one day soon burst forth. I initially thought the 'victim' had been attacked as he or she prepared to leave the pond and moult, but eventually the attacker released his grip and both animals returned to the water. This said to me that, in this case, leaving the water was purely an act of avoiding predation.

Emperor Dragonfly nymph leaving the water

The same could not be said for this individual. As it hauled itself up the Iris stem, looking very likely to begin final metamorphosis at any moment, it came under attack from a completely unexpected source...

This frog is the first frog reportedly seen in this pond for over 25 years, vertical walls making it an unlikely home for anything without the power of flight. The frog took several leaps at the dragonfly nymph, proving ultimately unsuccessful as the pond's previous contender as resident top predator managed to climb out of reach.

Dragonfly nymph ready to emerge from its larval case
Initially I thought the exertion had been too much for the dragonfly. Several hours later the nymph still hung unchanged. I feared it had  missed the moment and would die slowly in the tomb of its underwater skin, but the next morning I found an empty larval case and no dragonfly, so it must have made it to adulthood after all. No sign of the frog since, but I'm sure there's more than enough food to keep one solitary amphibian happy.

Detail of emerging adult
On my evening visit I did manage to catch one dragonfly mid moult, the video clip shows it pulling clear of the larval case and inflating the wings (sped up).

I had to go home before the wings were dry and skeleton hardened ready for adult life, but returning the next morning I was privileged to see and film another take off into the sky for the first time.

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