Tuesday, June 20, 2017

Species Spotlight: Four-spotted Skimmer

We saw our first Four-spotted Skimmers of the year a few days ago at Cranberry Lake. Curiously, we have never seen one at Heart Lake, even though it is only a few miles away and is very similar to Cranberry Lake. Eight-spotted Skimmers haven't been seen yet.

Heart Lake and Cranberry Lake are very similar, but have distinctly different dragonfly populations.

Here's a male Four-spotted Skimmer:

Four-spotted Skimmer, male.  Notice the dark spots at the nodus (center of leading edge) that give this dragonfly its name.  The dark spots near the wing tips (the stigma) don't count, since all dragonflies have them.  Also, note how the front two legs are folded up and tucked behind the head, just as they are in flight.

Males and females are practically identical in this species. The best way to distinguish them is by behavior—males patrol the shoreline looking for mates; females perch on vegetation when not dipping the tip of their abdomens in the water to lay eggs—and by the presence (males) or absence (females) of hamules under segment 2 of the abdomen.

Here's a female Four-spotted Skimmer, showing the lack of hamules, and the presence of a small egg scoop:





Here's a male Four-spotted Skimmer, clearly showing the hamules under segment 2 of the abdomen:





The hamules are like latches that hold the abdomen of the males and females together in the wheel position.

Four-spotted Skimmers have a high perching index (about 80 – 90%), and hence are easy to observe and photograph.  If you see a golden brown dragonfly in our area it's almost certainly a Four-spotted Skimmer, so the ID is fairly easy as well.

Mating is a rapid affair with these dragonflies.  Their short, pudgy abdomens aren't particularly flexible, and hence they stay in the wheel position for only about 10 to 15 seconds.  After mating, the female dips the tip of her abdomen repeatedly into the water to lay eggs while the male hovers above for protection.  They don't stay attached in tandem during egg laying, as do many meadowhawks, because their inflexible abdomens aren't well suited for that kind of maneuver.

Thursday, June 15, 2017

Species Spotlight: Dot-tailed Whiteface

Just a few days ago Betsy and I went to Heart Lake in Anacortes on a nice sunny, warm day. The dragonfly activity is picking up there now. We saw Common Green Darners, California Darners, a Variegated Meadowhawk. We also saw several Dot-tailed Whitefaces, our first of the year.

Here's the location of Heart Lake:



The Dot-tailed Whiteface is a mostly black, small dragonfly that loves to perch on lily pads. It's key field marks include a yellow dot on the abdomen (tail), and a chalk white face.



Not often noted, but also an interesting field mark, are the white wing tips, which are formed by light-colored wing veins that extend beyond the stigmas. You can see the white tips on three of the wings in the photo above, but the fourth wing tip is hidden in the shadows.

Here's another look at the Dot-tailed Whiteface:



Females look much like males, though more brownish in overall color.

The eyes of the Dot-tailed Whiteface are so black, and so shiny, that they show interesting reflections. The next photo shows a Dot-tailed Whiteface looking at the camera:



The two bright, almost circular, spots are reflections of the sun, much as you would see in a football helmet, as indicated below:



The broader, paler white patches in the eye are reflections of the bright white face.

Take a look for this interesting dragonfly on a lily pad near you!

Monday, June 5, 2017

Nice Dragonfly, Nice Day!

Some time ago, on a beautiful crisp Fall morning, Betsy and I took a short ferry ride from our home in Anacortes, WA to San Juan Island, in the heart of the San Juan archipelago of northern Puget Sound. In the photo below, we're coming into Friday Harbor, where the ferry terminal is located. After disembarking, we spent the day exploring the island by car—with an eye out for interesting dragonflies, of course.  We weren't disappointed.

Pulling into Friday Harbor on San Juan Island.

One of our first stops was Roche Harbor, where we had a nice lunch on the pier. Lots boats anchor in this harbor, and you can see many of their shore boats docked in the photo below. The name of the large boat in the foreground pretty well sums up the feeling of the place.

I went into an old Mom-and-Pop general store with wooden floors, crab traps, fishing gear, as well as groceries and snacks. I picked up a delicious ice cream bar for us.  It was wonderful on a pleasant day like this.

Roche Harbor, on San Juan Island, WA.

After lunch we headed for Lime Kiln Park on the western shore of the island. The land you see in the distance is Canada's Vancouver Island. The passage of water between the islands is the Haro Strait, known for frequent visits by pods of killer whales. We saw groups of porpoises, and a pod of whales in the distance.

A lighthouse overlooking Haro Strait on the west shore of San Juan Island.

Next, we dropped by a small pond that looked like good dragonfly habitat. Sure enough, we saw lots of Cardinal Meadowhawks, a few Striped Meadowhawks, and some Spotted Spreadwings. The activity level was quite good.

The pond was in the middle of a large sculpture garden. The photo below shows a dragonfly sculpture we found there. It was quite detailed, even in the wings and the eyes, and it made me think of the large dragonflies that flew during the Carboniferous period.

Dragonfly sculpture on San Juan Island.

This dragonfly was a bit large to hold in one's hand, but worth the try anyway.

"Nice dragonfly."

A beautiful day with fun adventures!

Thursday, June 1, 2017

Species Spotlight: California Darner

I went to Cranberry Lake yesterday to have some pictures taken for an upcoming issue of Fidalgo Living. It will be a cover story about the dragonfly whisperer, and the wonderful dragonflies of Anacortes. The article will appear in the August issue.

It's still fairly early in the season, and it was mostly cloudy yesterday, but I still saw one dragonfly at the lake—the California Darner. This is a small darner (the smallest in our range) and the earliest flyer. If you see a darner around here in May it's almost certainly a California Darner.

Here's what this charming little fellow looks like:

California Darner, male.  You can clearly see the "egg tooth" on the front of its thorax, which it uses to break through the larval skin when it emerges as an adult.

Notice the lack of a front stripe on the thorax, the cream-colored spots on the tenth segment of the abdomen, and the simple (blade shaped) appendages—all key features of the California Darner. Also notice that it is perched on the ground, another characteristic of these darners. The other common darners in our area – Blue-eyed Darner, Paddle-tailed Darner, Shadow Darner – almost always perch in a bush at hip to shoulder height. In our area, a darner on the ground is quite likely to be a California Darner, especially early in the season. Here's another example of one perched on the ground:

Notice the lack of front stripes on the thorax, the cream-colored spots on segment 10 of the abdomen, and the simple-shaped appendages.

Of course, they do sometimes perch on vegetation, which usually makes photography a bit easier.



As pointed out in a previous post, this darner lacks the eyebrows of the Happy-face Dragonfly, but it's eyes are beautiful nonetheless.



There are a lot of young California Darners out this time of year. Their eyes are brownish before they mature. Below is an example of a young male.

This is a young male California Darner. Notice the "wasp waist" that is characteristic of males.

In the next shot we are looking into the dorsal fovea of the eyes. This means that we see very large pseudopupils, giving the eyes a dark appearance.



These darners will have the place to themselves for a while longer before the next darners to appear—the Blue-eyed Darners—show up.

The flight season for the California Darner shows its early arrival and fairly early departure:



You don't see many of them after July.

As you might imagine from their name, their range is concentrated in the western United States.



From the range, you might almost want to change the name to the Washington Darner.

Tuesday, May 30, 2017

Species Spotlight: Blue-eyed Darner

One of the most striking dragonflies in the western United States is the Blue-eyed Darner. It is large and brilliantly blue in color. In fact, it's one of those dragonflies that you can easily identify on the wing.



Its range is primarily the western half of the United States, but one has to wonder about those errant reports from Cape Cod and Mexico.



Blue-eyed Darners perch in bushes at about chest height, typical hanging vertically like a Christmas ornament.



If you see one perched, try to get a good look at its wonderful blue eyes. Notice that its face is also blue, as are the stripes on the thorax.



As if all of these characteristics weren't enough to identify the Blue-eyed Darner, it has another unique feature—forked appendages.





One additional interesting feature is a small bump—tubercle—on the underside of segment 1 of the female. Here's a view of the bump:



This picture was taken at a fountain in Butchart Gardens last July.

Here's a pair of Blue-eyed Darners in the wheel position.



Be sure to look for this dragonfly in the coming few months. It's an early flyer, and is not seen very often after mid to late summer.

Monday, May 29, 2017

Happy Happy Happy-Face!

Over the years I've taken literally thousands of photos of the Happy-face Draongfly (aka, the Paddle-tailed Darner).  Here's a small sampling:


The two photos on the bottom right of the grid were taken on the deck in our backyard.  All of the rest were taken at Cranberry Lake, where we see the Happy-face Dragonfly all the time in the late summer and early fall.

The photo in the center is still my favorite.  In fact, it was the first one I ever took of the Happy-face Dragonfly, on October 22, 2006.  I reached into the bushes with my camera and took a shot of a dragonfly perched there without even looking at the viewfinder.  When I loaded the photo onto my computer at home I was amazed, and I called to Betsy.  "Take a look," I said, "this dragonfly has a happy-face!"  This discovery launched my interest in dragonflies, which has given me great pleasure ever since.

The following quote from Henri Poincaré summarizes my feelings about science and nature quite well.


I might add to this thought, however, that the scientist also delights in nature because it is infinitely intriguing and surprising – just take the Happy-face as an example!

I'm nearing completion of my dragonfly field guide, Common Dragonflies and Damselflies of the Pacific Coast, and one of its features will be spreads on things I've discovered in my days as a dragonflier, like the Happy-face Dragonfly, Splash-Dunk/Spin-Dry, Autumn Meadowhawks egg laying behavior, etc.

Below is the first draft of the left side of a spread on the Happy-face Dragonfly. It provides a view of a variety of Happy-face individuals, showing the variation in their facial features.



On the right side of the spread I compare the Happy-face of the Paddle-tailed Darner with the face of other species of darner. The Shadow and Variable Darners are in the same genus (Aeshna) as the Paddle-tailed Darner, and their faces are quite similar—including eyebrows that are actually pigments on the eyes. On the other hand, the California and Blue-eyed Darners are in a different genus (Rhionaeschna) and their eyes lack the eyebrows, giving them quite a different look.



It's fortunate that my first face picture of a dragonfly's face was of a Paddle-tailed Darner, since it has the most dramatic "Happy-face" look.

Tuesday, February 21, 2017

Species Spotlight: Blue Dasher

Well, we've finished up with the dragonflies with "black" in their name, and are now onto the "blue" dragonflies. First up, the Blue Dasher.

This is one of my favorite dragonflies for a number of reasons. First, it's very widespread in its distribution, so you're likely to see one almost anywhere you go dragonflying. Here's it's range map:


The only blank areas are the upper plains and Rockies.

Second, it's very cute and photogenic. The Blue Dasher strikes delightful poses for the photographer, and lands repeatedly on favorite perches. Here are a couple shots of the male Blue Dasher:




The blue color of the Blue Dasher is produced not by pigments, but by light scattering from the microscopic structures on its body—in much the same way that the scattering of light gives the sky its blue color.

The large area on the top of the Blue Dasher's eyes, where you can just make out the lattice of individual eyes (the ommatidia), is known as the dorsal fovea. It is the part of the eye that gives the dragonfly its highest resolution vision. If you look straight down on the dorsal fovea you see large black pseudopupils, as shown below. (By the way, the white spots are reflections of the sun.)



Female Blue Dashers are completely different in appearance. They are cryptically colored with a brown background and numerous yellow stripes:



The Blue Dasher—beautiful, widespread, easy to photograph. This species has it all.