Wednesday, March 30, 2016

First Damselfly of the Year, 2016

We saw our first damselfly of the year, Rambur's Forktail, the same day we saw the first dragonfly.  It flew on by us, however – surprisingly quickly for such a small insect – never to be seen again.

It was immediately recognizable by its green thorax and blue-tipped abdomen.  There's another forktail that's similar, the Desert Forktail, but it has yellow on the sides of the abdomen that extends up onto the top of the abdomen.  In Rambur's Forktail the yellow on the abdomen terminates in a nice, clean straight line about halfway up.  We haven't seen a Desert Forktail at our backyard pond, so we were pretty sure we were seeing a Rambur's Forktail.

A week or so later we went to Wild Horse Pass, and there we saw several Rambur's Forktails that were perching for us.  Here's a view of a male Rambur's Forktail at Wild Horse Pass:

Notice the green on the head and thorax, the blue tip to the abdomen, and the lack of yellow on the top of the abdomen.

Here's another male seen later the same day:

Heteromorphic females (those that don't look like males) start off bright orange when young, but with age turn more brownish and greenish.  Here's an immature heteromorphic female seen the same day at Wild Horse Pass:

Notice the nice straight line between the light color on the bottom of the abdomen, and the black on top – similar to the line of demarcation in the male.  We saw the female interact with a male, but she fended it off and they went their separate ways without mating.

Wednesday, March 23, 2016

First Dragonfly of the Year, 2016

We saw our first dragonfly of the year a few days ago flying around the lake in our backyard.  It was a male Red Saddlebags – the species that we observed laying eggs in the lake last year.  So far this year we've only seen the one individual at our lake, and we've only had fleeting glimpses of it.  Our first sighting last year was even earlier, by a few days.

A few days later we went to the Gilbert Water Ranch, where we saw several Red Saddlebags.  One, a female, perched for its picture:

This individual perched on a bush several feet back from the shore at Roseate Bay.  Notice how it folds its front two legs up and tucks them behind its head.  It generally flies in this configuration, as well.

Here's another look from a slightly different angle:

Both photos show a bulge extending below segments 8 and 9 of the abdomen.  This is the female's egg laying mechanism.

When saddlebags (both red and black) lay eggs they have a unique way of doing it.  It's a bit like the lunar landing, where the command module remained in orbit as the lunar lander descended to the surface, the astronauts got out to explore, and then the lunar lander returned to orbit where it re-attached to the command module.  In the case of saddlebags, the male hovers above the water as the female descends, taps the water to lay eggs, then rises to re-join the male.  It's a fascinating procedure to watch.

Here's a link to a slow-motion video showing the egg-laying process in the Red Saddlebags:

In this next video, you can see the process in real time.  Don't blink!

Finally, here's a video where a pair of Red Saddlebags is laying eggs, and another male zooms in and crashes into the pair in an attempt to break them up so he can have the female for himself.  The pair eventually re-attached, however, and continued to lay eggs: