Wildfire: I have been a tad distracted of late by a threatening wildfire. The danger is declining, but has not passed.
Skimmers are a family of dragonflies for which much of the identification involves counting spots. But, there seems to be an arbitrariness about just what should count as a spot.
For example, I suspect that this is a Four-spotted Skimmer, but where are the four spots? Halfway along the forward edge (at the nodus) of each wing is a dark spot. There are four wings, so a total of four spots. What about the dark spots near the tip of each wing? These are the stigma, and are such a common feature of dragonflies as to be not useful for identification. They are not counted.
Then there is a skimmer called the Common Whitetail. It does not even seem to be classified on the basis of the spots on its wings, despite some obvious big ones.
The classification of the Twelve-spotted Skimmer is a bit more obvious. Each wing shows three prominent dark areas, so with four wings altogether, twelve spots.
Two dark spots per wing give the Eight-spotted Skimmer, of which this picture shows two. Normally, a skimmer hunts from a perch. It spots another insect and heads out to capture it. However, males dislike the incursion of another male in their hunting and breeding territory. The resulting combat seems to be what was captured in this fleeting view of one Eight-spotted Skimmer challenging another.
Your photos present the differences so nicely! The dual/duel shot is amazing – requires a bit of luck in addition to a lot of skill.
I’m wondering why the white patches don’t count – that would give us Twenty-spotted Skimmer and Sixteen-spotted Skimmer.
I have yet to spot a Twelve-spotter – maybe I have have encountered same but skimmed over it.
Carlo, I suspect the white spots are not counted as they are not as reliably present.
Thanks so much for this excellent clarification, just what I needed. I’ve often wondered what exactly constitutes a spot.
Alistair,
I find your explanation spot on.
Derek, albeit a somewhat spotty treatment.
Hi _ I read somewhere that the white spots are present on a male but not a female. Myth or truth? I do not know.
Jana, I believe that is correct that the white is male thing.