Saturday, April 14, 2018

Refresher on Roseate Bay

Here's the post where I introduced Roseate Bay.

Another place we like at the Gilbert Water Ranch is what we call Roseate Bay, so named because Roseate Skimmers are so abundant there.  It's located at the northern end of Pond #5 in an area that stays wet all the time, while most of the pond dries up.  Its location is indicated on the map below:

There's also a nice shaded viewing blind at Roseate Bay.  It's a great place to see 3 or 4 Roseate Skimmers perched at a time, while in the background all sorts of ducks and shorebirds are feeding.

Here are a couple shots of a Roseate Skimmer at Roseate Bay.  They're very active right now, and often just perch for a few seconds before taking off again, but every now and then one rests for long enough to get some good shots, as with the individual below:

Roseate Skimmer, at Roseate Bay, Gilbert Water Ranch.

Notice how the front two legs are tucked up nicely behind its head—as can be seen more clearly in the photo of the same individual below.  This is where they hold the front legs during flight as well.  Once the rear four legs capture an insect, the front two legs come into play as they manipulate the prey item for processing.

Also observed at Roseate Bay were a couple Variegated Meadowhawks.  Here's one on a stem, watching for something to take off so it can give chase.

Variegated Meadowhawk, Roseate Bay, Gilbert Water Ranch.

The same individual as above from a different angle.  Notice the two yellow spots on the side of the thorax.  When it was younger, there would have been two white stripes on the thorax, with yellow spots at the bottom.  With age, the white fades away, leaving just the yellow spots.  Notice also the intricate pattern on the abdomen, the reason for its name.

Friday, April 13, 2018

Roseate Skimmer at Roseate Bay

There's one spot at the Gilbert Water Ranch that we refer to as "Roseate Bay" because we often see Roseate Skimmers there. Today we saw our first of the year, a young male. Here it is:

The roseate colors haven't developed yet, but they will soon.

Why is this a male? Well, first, the hamules are visible under segment 2 of the abdomen; second, the appendages are fairly large; third, the tip of the abdomen lacks the flanges associated with the egg scoop of the female of this species. Here's a look at two females from last season—the top two in the photo below—showing the flanges near the tip of the abdomen:

It's also clear from the above photo why this area is called Roseate Bay.

Here's another view of today's male:

You can just see a hint of the roseate color to come. Dragonfly season is getting started!

Thursday, April 12, 2018

Species Spotlight: Desert Firetail

The Desert Firetail is a small delicate damselfly that likes to lay eggs on floating vegetation, like lily pads or algae. The male's abdomen is a fire red color—hence the common name.

Here are a couple males resting near a pond:

The red abdomen and short wings make this an easy damselfly to identify. Here's a photo that shows just how short the wings are in this species:

This is a male—as can be seen from the protrusion under segment 2 of the abdomen (the hamules) and the lack of an ovipositor at the tip of the abdomen. It is a young male, as evidenced by the light red color on the abdomen.

Pairs lay eggs with the male attached to the female. Males stand upright when attached, and if a group is laying eggs together the males can look like red blades of grass. Here's a pair in which the female is laying eggs on the underside of a lily pad:

A closer look at the female shows how the male is attached to the front of the female's thorax—not to the back of her head, as in dragonflies:

You may observe adults emerging from their larval (naiad) skins in the same general area where the eggs are being laid. Here's a larva that was swimming a few moments before the photo was taken, but who is now drying out on a lily pad, getting ready for the adult to emerge.

In a matter of minutes, the adult makes its appearance:

Soon thereafter the adult is fully emerged from its larval skin, and it now begins to pump up its abdomen and wings to their final size.

Ah, such is the life of an odonate!

Tuesday, April 3, 2018

Dragonfly Alley

A few days ago we visited an area that was new to us, referred to locally as "Dragonfly Alley." On the map its proper name is Queen Valley, and it lies about midway between Gold Canyon and the Boyce Thompson Arboretum. Here's a map of the general area:

Here's a close-up view of the community itself:

Queen Valley is a small little town, centered around a source of water and a golf course. There's nothing else near it—just wild desert.

It also happens to be a great place for dragonflies and damselflies. Over the year, a total of 59 species have been seen in Queen Valley. We went early in the season, so our species list was more like 15 or so. And since this is an early-season population, it consisted of about twice as many damselflies as dragonflies—more or less the reverse of what is typically seen in mid season.

The first odonate we saw as we got out of the car was the Aztec Dancer.

What lovely, intense blue colors it has on both the body and the eyes. Here it is taking off:

This species preferred the shoreline of one of the ponds on the edge of the golf course. Also prominent in the same area was the Familiar Bluet:

Notice how the bluet folds its wing along the abdomen—almost forming a "tent" over the abdomen. In contrast, the wings of dancers are held high above the abdomen.

At a nearby stream, we found the Springwater Dancer.

We were looking for an American Rubyspot here as well, since this is their preferred habitat. After a few minutes one indeed showed up:

One of the most interesting odonates we saw that day was a female Filigree Skimmer. Here she is perched in the sun:

She blends in to the surroundings so well with her wings that look like dried-up leaves and her abdomen that looks like a twig. Notice also her boldly-striped eyes and prominent egg scoop under the abdomen near the tip. Quite the dragonfly.

Queen Valley was a fun place to explore. It's just a small valley in the middle of the desert, hot as blazes, but a great spot for dragonfly watching.