Thursday, April 30, 2020

First Of The Year: The Odonates Are Back!

We saw our first odonates of the year today at Little Cranberry Lake here in Anacortes. We had been looking for them for the last couple weeks, but today, quite suddenly, they were here in numbers.

Our first sighting was a female Pacific Forktail resting on a twig away from the shore, soaking up the sun:

A few minutes later we found another one on a fern leaf not far away:

Notice that the female has only a single blue segment at the tip of the abdomen. In addition, she often has a stripe on top of the thorax rather than spots as in the male. The stripe may break off in the middle, however, as in the first individual.

A short time later we saw a male on a floating twig near the shore:

The male has nice distinct spots on top of the thorax, two blue segments at the tip of the abdomen, and hamules under segment 2 of the abdomen. He was at the water waiting for a female to mate with; the females were away from the shore where they can rest and feed.

We also saw a couple female California Darners flying back and forth along the shore, and occasionally perching on the ground—as is their want:

Notice the lack of front stripes on the thorax, as expected for a California Darner. The fact that these are females is attested to by the wide segment 3 of the abdomen, flat segment 2 on the underside (where the male's hamules would be found), ovipositor on the underside near the tip of the abdomen, and cerci only (upper appendages) with no lower appendage.

We'll keep checking from day to day now that we have a thriving population to investigate.

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