Damselfeast 2015

The Rambur's Forktail damselfly (Ischnura hastata) is one of the more widespread and common damselflies in my area, and across the southern part of the country, really. Its range even extends into Hawaii, according to the sightings map from Odonata Central:
Range of Rambur's Forktail in the United States. Map courtesy of Odonata Central.

Range of Rambur's Forktail in the United States. Map courtesy of Odonata Central.

There are a couple of reasons this damselfly has such an extensive range. One is that they are fairly large, dwarfing their relatives, especially the tiny Citrine Forktail (I. hastata) or the equally dainty Everglades Sprite (Nehalennia pallidula). Another reason might very well be that they are badasses! I was sitting on the couch one lazy afternoon while the wife and kids were at the library when I noticed an Everglades Sprite drifting near the doorknob of one of the French doors that lead out onto the pool deck. I ran into my office to get my camera, but by the time I got back, a female Rambur's had taken notice of this Everglades Sprite as well. And here is what ensued!
What lovely eyes, you have. Come closer, my dear, that I might see them better.

What lovely eyes, you have. Come closer, my dear, that I might see them better.

Your neck seems tight. Here, let me adjust it for you.

Your neck seems tight. Here, let me adjust it for you.

Whoops! Sorry!

Whoops! Sorry!

Well, there's no putting the milk back in the bottle.

Well, there's no putting the milk back in the bottle.

Mm-mm! Good to the last bite!

Mm-mm! Good to the last bite!

The first two pictures were overexposed because I had left the camera in "bird" mode,1 which means wide open lens. Adding flash to that means the pictures were almost solarized. Good thing digital processing is so powerful; you can at least see the action! Here is a bit more about the species, for those who are interested. Like the range map above, this is from Odonata Central:
Rambur's Forktail is the most widespread forktail of the New World, ranging as far north as Maine, southward to southern California, Mexico, Central and South America. . . . It also inhabits the Hawaiian Islands, where it was introduced in 1973. . . . As widespread as this species is, surprisingly little has been written about its biology. Both sexes will remain close to the water and although males are not territorial, females are known to be highly predaceous and often cannibalistic. Males often do not release females from the wheel position for several hours, and sometimes as many as seven, to secure their genetic contribution. Red females will sometimes attack males, but more often curl their abdomen downward while fluttering their wings in a refusal display.
I bring to your attention the relevant bit from the description above: "females are known to be highly predaceous." As the Everglades Sprites attempting to get their mack on just a few feet away might say, "tell us about it!"
A pair of Everglades Sprite attempting to seal the deal just two feet away from one of their brethren being eaten by a Rambur's Forktail. Survival of the fittest, indeed!

A pair of Everglades Sprites attempting to seal the deal just two feet away from one of their brethren being eaten by a Rambur's Forktail. Survival of the fittest, indeed!

References Odonatacentral.org Paulson, D. (2011). Dragonflies and Damselflies of the East. Princeton, NJ: Princeton UP.

After the rains, the odonates appear

South Florida is typically described as having two seasons: wet (May through October) and dry (November through April). Hydrologists like to split this up a bit further, with the wet season (now called high rainfall, low evapotranspiration season) running June through October, and the dry season now divided into two subseasons: low rainfall, low evapotranspiration (November through February) and a low rainfall, high evapotranspiration season (March through May). What this translates to in layman's terms seems to be something like "wet, then dry, then really dry." Over the last three years, two Aprils have been fairly wet (7.5 inches at my rain gauge this year, and a whopping 9.22 inches the previous year), while one was quite dry (in 2011 we had only 1.15 inches of rain in April). This year, May started off with a bang: Over six inches of rain in the first three days, five and a half of them in one long rainy day that also included at least one tornado here in Boca Raton (at my dentist's office, no less!). All that moisture falling from the sky, saturating the local soil, has an effect on wildlife. Saturday morning, after what seemed like forever, the yard was full of odonates again. Damselflies (Rambur's Forktails, Fragile Forktails, and Everglades Sprites) and dragonflies both (Blue Dasher, Little Blue Dragonlet, Eastern Pondhawk) were flitting around in the tall grass (after months without having to mow, I can see that I'll be back out on a weekly basis with my trusty reel mower—no gas for me!). Here's a shot I liked of one particularly patient Everglades Sprite (Nehalennia pallidula):
Everglades Sprite (Nehalennia pallildula). Boca Raton, FL, May 4, 2013.

Everglades Sprite (Nehalennia pallildula). Boca Raton, FL, May 4, 2013.

As usual, you can click on the image for a larger view. If you look closely, you can see the individual facets in the right eye:
Everglades Sprite (Nehalennia pallildula), detail. Boca Raton, FL, May 4, 2013.

Everglades Sprite (Nehalennia pallildula), detail. Boca Raton, FL, May 4, 2013.

As you may recall, those individual facets in the compound eye are called ommatidia. These tiny simple lenses, in combinations of hundreds (in the simplest compound eyes) to tens of thousands, form a complete image in the brain of the animal. The more ommatidia there are, the greater the visual acuity of the animal in question (in addition to insects, millipedes and mantis shrimp have compound eyes featuring ommatidia). In that respect, they function very much like the pixels on a CCD chip: as you add more pixels to your camera, you can create larger and larger images at high resolution. (Can you tell I got a new camera recently? One with a ridiculously high pixel count?) Another damselfly appeared a bit after I got tired of chasing those sprites around. This one is a Fragile Forktail (Ischnura posita):
Fragile Forktail (Ischnura posita). Boca Raton, FL, May 4, 2013.

Fragile Forktail (Ischnura posita). Boca Raton, FL, May 4, 2013.

And there was the ubiquitous Rambur's Forktail as well:  
Rambur's Forktail (<i>Ischnura ramburii</i>). Boca Raton, FL, May 4, 2013.

Rambur's Forktail (Ischnura ramburii). Boca Raton, FL, May 4, 2013.

Here's the first dragonfly I've managed to image so far this month; the Blue Dasher (at one point the most commonly photographed odonate on odonatacentral.org):
Blue Dasher dragonfly (Pachydiplax longipennis). Boca Raton, FL, May 4, 2013.

Blue Dasher dragonfly (Pachydiplax longipennis). Boca Raton, FL, May 4, 2013.

And here's the second. (Surprise, surprise! Another Blue Dasher):
Blue Dasher (Pachydiplax longipennis. Boca Raton, FL, May 4, 2013.

Blue Dasher (Pachydiplax longipennis. Boca Raton, FL, May 4, 2013.

And the third, a different species this time (Little Blue Dragonlet):
Little Blue Dragonlet (Erythrodiplax minuscula). Boca Raton, FL, May 4, 2013.

Little Blue Dragonlet (Erythrodiplax minuscula). Boca Raton, FL, May 4, 2013.

If this keeps up, it might be an interesting season for backyard wildlife after all!