When a robin, say, arrives at your bird-table, you might remark that 'the robin is here again'. But how do you know that it's the same one that comes every day? Similarly with dragonflies. They make regular excursions to the garden pond but it's not really known if they are always the same individuals.

These are close-ups of female southern hawkers and female emperors taken while they are laying eggs. These species oviposit on their own and if they are near the edge of a pond it's possible to get close-ups of their faces. These are interesting in their own right and the facial features of these two species are quite different. In this particular case, though, the eyes are the subject of interest.

When comparing the dark spots and smudges of the eyes in different photos there does appear to be some slight variation. Human eyes alter according to circumstance; maybe dragonfly ones do as well? Is there enough significant variation to be able to say that we are looking at different specimens? One could table more questions along these lines. So we end up with far more questions than answers but it is conceivable that eye patterns could identify certain individuals.
Possible research topic?

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