Swarming Mayflies, why?
But only the male Mayflies swarm… Score: ‘Mayfly Days’ by Natalie Edelson – nataieedelson or natalieedelson For my collection, see my playlist Sublunary …
Lots of animals live part of their life or their whole life
in swarms, flocks, schools, etcetera
Such swarms sometimes show fairly complicated movements.
These swarms seem to act as a unity, a single system.
By swimming or flying on mass,
the predator becomes dazzled, so it's unable to pick one out.
Also mayflies swarm.
Near non-polluted lakes
you can see each spring
huge swarms of these fragile insects.
Worldwide two thousand and five hundred species
of the mayfly are known.
starts its life as a 'nymph',
living – depending on the species –
from two months to two years in the water.
After transformed into a fly,
it lives for thirty minutes to one day,
some species even a week.
They can't eat and their stomach is only filled with air.
Only the male mayflies swarm.
And here we are,
this is a tiny swarm in my garden in May.
To see the flies better, I positioned
a blackboard behind the swarm.
Only when the flies are shined on by the late
afternoon sun, you can see them.
When I put my arm in this swarm
the whole swarm moves away.
They don't like humans,
To see the flies even better on the video,
I used 'color replace'
to attain a smooth background.
So don't forget these moving white dots
are real flies!
Sometimes the swarm spontaneously moves as a unity.
In the replay.
I noticed that when the dove in the background cooed,
the swarm dissolves.
I tried to replicate this finding
by clapping my hands.
But, as you can see, hardly any reaction of the swarm.
Interestingly, the swarm reacts clearly upon my booing.
Let's follow one fly.
It seems that this fly [like all flies] likes to be
in the center of the cloud.
I can check that by fixating the fly-paths
of all flies in this swarm.
And indeed, now the cloud can be seen.
The border of the swarm space of these mayflies
appeared to be rather clear.
And you see never a collision.
But sometimes they bump into each other on purpose,
because mayflies mate during flight.
Perhaps, this is a female
entering the swarm of male flies.
It could be
In slow motion…
Hereafter the female lays its eggs in clear water,
Also the male dies within an hour.