The Not So Common Green Darner – Terry Thormin
Although the day started out on the cool side, as the clouds cleared it gradually warmed up nicely, warm enough to make me think about going out to Little River Pond in the afternoon. There is one photo that, after almost three summers of trying, I still have not been able to get, a shot of the Common Green Darner in flight. Oh, I have come close. I have taken some fuzzy, out-of-focus shots, and I have, on several occasions, almost managed to get the shot. What makes this all the more frustrating is that my cousin Mike had managed to get at least two good in-flight photos of this dragonfly on his very first visit to the pond.
So once again I found myself sitting in my camp chair at the edge of the pond, following the dragonflies as they patrolled the edge of the pond looking for mates, and hoping that a Common Green Darner would hover long enough for just one shot. Well, I never did get my photo, but I did see something that I have never seen before. There was lots of mating and ovipositing going on, and I am always interested in improving my shots of the darners ovipositing. Just in case you are not sure, ovipositing means egg-laying.
When dragonflies mate they do so in the wheel position. The male uses the appendages at the tip of his abdomen to grab the female at the back of the head and the female then curls her abdomen under her thorax and makes contact with the second segment of his abdomen where he has deposited his sperm. This forms an irregularly shaped wheel. I have never been able to find perched Common Green Darners in the wheel positon, but here is a photo of a pair of California Darners in this position.
When the female is ready to lay eggs, she disconnects her abdomen from the male’s abdomen. At this point the technique used by the female for egg laying varies depending on the group of dragonflies. In the case of the Common Green Darner, the male continues to grab the female at the back of the head, and they fly in tandem like this from floating vegetation to floating vegetation.
They will land on anything that has a submerged stem and the female will proceed to probe the stem underwater with the tip of her abdomen. She will then make a slit in the stem with her ovipositor and insert a single egg. At times she will reach so far down the stem of the plant that her whole abdomen and part of her thorax are under water. She will do this over and over again, laying several eggs in one stem and then moving on, with the male still in tandem, to another plant to lay more eggs.
During this procedure it is not uncommon for another dragonfly to hover over the ovipositing pair. This is sometimes a male of a different species, but often another male Common Green. I have at times seen male Common Green Darners actually dip down and “attack” the male that is in tandem with the female. The theory is that the male stays in tandem with the female to ensure that she does not mate with another male before laying eggs. This attack then might be an attempt on the part of the single male to dislodge the male in tandem. I have never photographed a lone male Common Green Darner attacking or hovering over a mating pair, but this photo shows a male Blue-eyed Darner hovering over a pair of Common Greens.
On this occasion, as I was watching a pair in the process of ovipositing, a lone male flew in and landed right on the back of the female. It then looked as if he reached forward and bit the other male right near the tip of his abdomen. This caused the male in tandem to immediately lose his grip and fly forward a short distance. What happened next was so quick I almost didn’t catch it all. The interloper reached forward with the tip of his abdomen, grabbed the female on the back of the head with his appendages, and took off like an arrow with the female in tow.
The other male, in the meantime, circled around and came back to the spot where the female had been laying eggs and circled around, legs dangling down, apparently looking for his mate. After circling around for about 30 seconds he flew away, but then came back a short time afterwards and did the same thing again before finally flying away for good.
I have never seen this behavior before, and have never read about it anywhere. I am curious to know if it is something that has been observed by other people. Unfortunately it all happened so quickly that I was unable to get photos. Like everything else in nature behavior evolves and perhaps this is a newly evolving behavior in Common Green Darners.