I’ve been trying to observe and learn about Odonata, that is, Dragonflies and Damselflies, and I’ve made slow progress but some progress. Seems like every time I observe and identify a new species, I mess up on the identification of other species that I’ve observed in the past and should know. But I’ve been working on identification and thought I would mention a few tricks.
These learning tricks work for me but everyone is different. For me, I can only pick up so much information and then I have to “use it” in some fashion or it just becomes a muddle. And as I mentioned, I may think I know a species and then mess up entirely when identifying it again. (Any confidence is overconfidence.)
One persistent area of difficulty has been the identification of female damselflies. I always seem to get those confused.
But they aren’t my only issue. I’m terrible with color differences and size (I’ve had that issue with birding, too) so for example to say that the Attenuated Bluet, Enallagma daeckii, is long and slender–longer than any other pond damsel in North America–doesn’t really help me much unless I see two species near each other and can compare them that way.
However, one thing that does help me is to create comparison charts for myself which include species that I tend to confuse (for whatever reason). Here is what I mean.
| Characteristic | Attenuated Bluet Male | Pale Bluet Male | Attenuated Bluet Female | Pale Bluet Female |
| Eyes | Blue over green | All Blue | Tan, darker above with two brown lines encircling upper half | light blue over tan |
| Eye Spots | Large pale blue spots | Large pale blue triangular-shaped and a thin black line between eyes | Large pale triangular-shaped | |
| Head | Almost all pale | Blue; Black in the back | Blue with fine black marks | |
| Thorax | Light blue | Light Blue | Greenish tinged with blue | Light blue |
| Stripes | Very thin to no black median and humeral, humeral often broken | Narrow black median and humeral stripes | Narrow tan median and humeral stripes with black edges | |
| Legs | Pale | |||
| Abdomen | Black above | Black above | Black above, scarcely any basal rings | |
| S1 | Pale blue | Blue | ||
| S2 | Blue on sides | Blue sides | ||
| S3 | Blue on base | |||
| S7 | Blue on distal third, blue extends to tip of S7 | Blue with black stripe on upper surface | ||
| S8 | All blue | All blue | Blue with black stripe on upper surface | Blue with black basil triangle |
| S9 | All blue | All blue | Blue, brighter and may be greenish | |
| S10 | All blue | All blue | Blue, brighter and may be greenish | |
| Overall | Very long and slender, Almost no black on head, thorax, or abdomen tip | Color ranges from light blue to greenish-blue or tan | ||
| Behavior | Perches higher than other bluets; hovers |
Now don’t go and use the table above–that’s not the point. I’m only including it here as an example of the kind of thing I create to help me learn the differences between species. Creating your own version of this kind of table may be helpful to you and can be applied to almost anything. Also, I should note that I have a more extended version of this with the “missing” segments (S4, S5, and S6) in cases where those segments have distinctive characteristics. And other version with thorax stripes (e.g. T1, T2) that are important and distinctive. The table can be modified to highlight any distinctive characteristics. And it can be used for birds that are likely to be confused, as well (Flycatchers as a group of species come to mind).
The other advantage to doing this: in the past when I’ve posted observations on iNaturalist, some kind souls have added comments about distinguishing marks when correcting my mistaken species. Those comments are invaluable since they are often not to be found anywhere either online or in guide books. Those are definitely the kind of information that needs to be included in these comparison charts.
I do these particular charts as spreadsheets, but they can be done as documents or in any fashion that is most useful. It’s one way to help me learn.
Using iNaturalist is another at least for identifying species in the natural world around us. I make loads of identification mistakes, and I’m sure the experts (especially Odonata experts) must get really tired of seeing me upload a bunch of observations of what are obviously Blue-tipped Dancers but I just blithely label as Variable Dancers (sigh). Even when I really do know better. Brain cramp.
About the only thing similar on these dancers is the purple on the thorax, but even that is different since the Blue-tipped Dancer has a much darker purple thorax and no purple/violet at all on the abdomen.
So I hope this helps someone–maybe just to give them a good laugh if nothing else.
