Monday, July 25, 2016

Butchart Gardens

A couple days ago, Betsy and I visited Butchart Gardens on the way back from our cruise to Alaska.



It's a lovely place, and the weather was perfect.  Flowers everywhere, of course.







Many darners were flying over the open grassy lawns, but no other odonates were seen for a while – until we came to the "Star Fountain," shown above.  There we saw lots of Tule Bluets, including one that liked to perch on the begonias:





Notice the almost equal-width bands of black and blue on the abdomen, with the black bands actually a bit wider than the blue ones.  The Northern and Boreal Bluets differ in having mostly blue on the abdomen, with small black rings separating them.

In addition, we saw a darner fly in and land on one of the "frogs" that shoots out streams of water.  Here it is:



It's clear that this is a female, due to its overall brownish and greenish color, and the expanded tip of the abdomen that holds the ovipositor.  Females are generally a bit more difficult to identify than males, but in this case the identification was easy.  Notice the small "bump" – or tubercle – below segment 1 of the abdomen.  Here's a better view of the bump:



The interesting thing about this bump is that it's a distinctive field mark for the female Blue-eyed Darner.  None of the other mosaic darners in our area have this bump.  It's a good field mark to look for, though it's not always as easily seen as it is in this view.

Sunday, July 10, 2016

Lower Crab Creek, Dragonfly Eden: Emma's Dancer

Betsy and I went to Lower Crab Creek in Eastern Washington a few days ago.  The dragonfly activity there is astounding – dragonflies are definitely the most common form of wildlife in the area.  The location is about 4 miles east of the tiny town of Beverly, Washington, on Road 17 SW.  Here's a map showing the site:


The setting is spectacular, as you can see from the background of this picture of Betsy looking for dragonflies in the bushes:


We saw a number of beautiful species there, including some we don't see in Puget Sound, and a few that were new for us.  I'll start with a damselfly species that we've seen before, Emma's Dancer, but never in these numbers.  Here's the male of the species, easily identified by its lovely lavender color, and blue-tipped abdomen:



The female is a tannish-brown color:


What a beautiful damselfly.  It was so nice to have them everywhere we looked.

Wednesday, June 22, 2016

Heart Lake Dragonflies

We had a great time dragonflying at Heart Lake a few days ago.  Lots of individuals, and several species, were seen – including species we never see at nearby Cranberry Lake.

Heart Lake gets its name from its roughly heart-shaped outline, as can be seen in the following map:

Heart Lake (center, bottom) in relation to downtown Anacortes.  Cranberry Lake is just above center.

Perhaps most striking dragonfly at Heart Lake was the Cardinal Meadowhawk, with its intense red colors showing off nicely in the bright sun.  Here's an example of one of the males:

Male Cardinal Meadowhawk at Heart Lake.

In this next view you can see what I regard as its best field mark, the intense concentration of red color near the wing bases.

Male cardinal Meadowhawk.  Notice the dark red, opaque regions in the wings near the base.  An excellent field mark.

This field mark is completely diagnostic, and visible from almost any angle.  It will be featured prominently in my forthcoming field guide.

Notice also the intense red color on the abdomen.  It almost over saturates the eyes.

The Cardinal Meadowhawks were also laying eggs, which they do while attached in tandem.  Here's an example:

Cardinal Meadowhawks laying eggs in tandem.  The female dips the tip of her abdomen in the water to deposit her eggs.

While this pair was laying eggs, a lone male was trying to break them apart so he could replace the current male, as can be seen below.  It didn't work, though he was pretty persistent.

A lone male Cardinal Meadowhawk unsuccessfully attempting to break apart an egg-laying pair.

We also saw numerous Dot-tailed Whitefaces – more than I've ever seen before.  They were everywhere, flushing from the ground or grass with every step, and also sitting on their favored perches – lily pads.  Here are a couple photos:

A male Dot-tailed Whiteface showing off its yellow dot.

In this photo you can see the chalk white face reflecting from the jet black eyes.

Notice the cute little yellow spot, or "dot," on the abdomen, the reason for its common name.

Friday, June 3, 2016

Ship Harbor Interpretive Sign

A couple days ago we went to the Ship Harbor Interpretive Preserve, which is here in Anacortes, near the ferry terminal.  Here's the location on a map of Anacortes:



When you get to the preserve you see this welcoming sign:



It's a very nice little park, with extensive boardwalks through the wetlands.  It also has nice views of Mount Baker and the ferries coming and going:



Lots of birds can be found in the wetlands:





In addition, Ship Harbor is home to a good-sized colony of Purple Martins nesting in boxes that have been provided for them.  The boxes are located on pilings in the water that are left over from a cannery that was at this site many years ago:



The martins are very active this time of year.  We saw several females coming to the beach to get grass stems for their nests.  In addition, we saw lots of interaction between the birds in flight:





Of particular interest to us were the interpretive signs along the trail, pointing out interesting plants and animals that can be seen in the preserve.  Here's a group of three such signs that was especially interesting to us:



If you look carefully, you may notice that the top sign looks a bit familiar.  Here's a closer view of these signs:



Now you can see the focus of our attention – the Happy-face Dragonfly.  Here's a closer look at the sign:



It's nice to know that people visiting the preserve, many of them taking a quick walk as they wait for the ferry, will have the opportunity to learn about the Happy-face Dragonfly.

Wednesday, May 25, 2016

Male-Male Interactions in Darners

Here's an article I've just submitted to Argia, the journal of the Dragonfly Society of the Americas.  The article details my observations of darners interacting more and more aggressively as the end of the flight season nears.


Male-Male Interactions in Darners
James S. Walker
Anacortes, Washington

Cranberry Lake in Anacortes, WA (Figure 1) is a wonderful place to observe dragonflies – especially darners.  The first species to start flying is the California Darner (Rhionaeschna californica), followed in short order by the Blue-eyed Darner (Rhionaeschna multicolor).  Later in the season, in October and November, the darner population shifts to Paddle-tailed Darners (Aeshna palmata), with a few Shadow Darners (Aeshna umbrosa) tossed in for good measure.  As a result, Cranberry Lake is an excellent place to observe darner behavior throughout the flight season. 











Figure 1 Cranberry Lake, home to many darners.

Over the years, it has become apparent that the way darners interact with one another evolves as the season progresses.  Early in the season, darners fly in mixed flocks – though comprised mostly of males – at convenient hill-topping locations, where the individuals hunt for prey peacefully with little interaction (see the online video links at the end of this article).  This is the time when the darners are feeding to attain maturity, after which they return to nearby ponds or lakes to mate.

As the season progresses, and more and more darners are present at local waters, the interactions begin in earnest.  In what follows, I describe the types of interactions, and the changes in behavior, observed at Cranberry Lake – both during the peak of the season, and extending well into the final days of flight.

Peak Season Interactions

Interactions during the peak of the season are observed to be rather benign and, one might almost say, gentlemanly.  Darners patrol the shoreline of their territory, looking for rivals, mates, and prey.  When a second darner flies into the territory of a resident darner, the resident flies toward the intruder.  Typically, what happens next is a respectful assessment of the situation, in which the intruder changes course to navigate out of the disputed territory.  Once the resident darner observes the change in trajectory of the intruder, it changes course as well, and returns to its territory.

As mentioned, these interactions are usually peaceful affairs, with no physical contact between the competing darners.  The darners approach to within a few feet of one another, veer off as they change course, and go their separate ways.  As the season progresses, the situation changes.

Late Season Non-Contact Interactions

Late in the season, when the days are growing shorter, the air is getting cooler, and the biological imperative to mate is intensifying, the interactions between darners takes a decidedly aggressive turn.  The first signs of change are apparent in the way a resident darner interacts with an intruder.  Often we see that instead of veering away from the intruder once the intruder is heading out of the territory, the resident keeps up a prolonged chase – though, again, generally without physical contact.  

In such cases, I’ve observed the resident male persist in chasing the intruder to an extent that seems, to a human observer, beyond all reason.  Even though the intruder is clearly departing the area, and seems no longer to pose a threat, the resident darner expends a great deal of energy and time in an extended chase.

Sometimes, the intruder is so pressured by the resident that its wings clip the water as it zigs and zags trying to escape.  In other occasions, the intruder intentionally plunges into the water in a splash/dunk (Walker 2011-2014, and online video), and then, as the pursuing resident continues on its course, the intruder emerges from the water and takes off in the opposite direction.  Clearly, drastic circumstances result in drastic measures.

The aggressive harassment described above still results in no physical contact.  Cases that do involve contact become more and more common as the season progresses.

Late Season Contact Interactions: The Final Days of Flight

As the end of the flight season approaches, the interactions between darners become more frequent, and more physical.  Males are seen to attempt to attach in tandem with other males, and to grapple with one another in flight for extended periods of time.  The whole tenor of their interactions changes.

The first sign of contact interactions is observed in perched darners.  Even though darners are flying dragonflies, they do perch from time to time to rest, eat large prey, or sunbathe.  They hang vertically in a bush with full exposure to the sun, as shown in Figure 2.  It’s common to find 3 or 4 darners perched at a time in the bushes near the shore of Cranberry Lake in peak season, but the number roughly doubles or triples near the end of the season, as more darners seek to warm themselves in the sun. 



Figure 2  A perched Paddle-tailed Darner at Cranberry Lake in its usual vertical orientation.

In late season, there may be a dozen darners perched in the bushes, but still with plenty of room to accommodate all of them.  Even so, they are often seen perched near one another, as in Figure 3.  What’s really odd, though, is that a darner coming in to perch often lands on an already perched darner.  Close observation reveals that the incoming darner lands on the thorax of the perched darner, and bends its abdomen downward and forward in an apparent attempt to attach in tandem.  At this point the perched darner takes off, and the two darners continue their interaction in flight.



Figure 3  Two darners, a Shadow Darner on the left and a Paddle-tailed Darner on the right, perch near one another.

At the same time, many in-flight interactions can be seen along the shoreline.  Competing darners no longer veer off in different directions, or engage in extended pursuits, but aggressively grab one another in flight.  In some cases I’ve captured in slow-motion videos (see online videos), the two darners hang on to one another and spin round and round in flight – much as two eagles locked together with their talons.  In one particular case, they grapple with one another for 1.9 seconds as they fall toward the water, only releasing their grip just before splashdown.  They gain altitude for 0.75 seconds, and then go back at one another, clenching for another 2.3 seconds, before taking off for more interactions.

In another case, the two darners actually landed in the water as they struggled.  While floating there, the top male repeated banged the tip of its abdomen against the head of the darner below it for over 4.5 seconds, as it tried mightily to attach in tandem.  It finally gave up, flew upward to gain altitude, and 0.9 seconds later the other darner managed to escape the water as well.  Interactions like this were common at this time of year.

These observations are only anecdotal, and may not present an accurate picture of darner behavior throughout a season.  Additional observations will form a more complete picture, but so far it seems that darner interactions are much more aggressive and physical late in the season, when the darners only have days left to fly.

Conclusion

Darners interact with one another frequently all year long, but their interactions become more intense and physical in the waning days of their flight season.  Males land on one another, or grab one another in flight, and appear to attempt attachment in tandem.  Late season interactions lead to explosive events at Cranberry Lake in October and November, and likely the same type of behavior can be observed at any location with a healthy darner population.

Acknowledgements

I would like to thank Betsy Walker for her support and help with these observations.

Literature Cited

Walker, J. S. 2011.  Spin-Dry Dragonflies.  ARGIA 23(3): 29-31.

Walker, J. S. 2011.  Splash-Dunk Analysis.  ARGIA 23(4): 29-30.

Walker, J. S. 2014.  Splash-dunk Analysis for 2011-2013, Including Temporal Distribution.  Argia 26(1): 33-34.

Walker, J. S. 2014.  Splash-Dunk Analysis for 2011-2014.  Argia 26(4): 32-33.

Online Video Links

A number of slow-motion videos showing various aspects of dragonfly behavior can be found on the Dragonfly Whisperer channel on YouTube.  Here are a few that are pertinent to this article:

Non-interacting darners in a feeding group.
Soaring Darners with Mount Baker

Gentle, non-contact interaction with zig-zag flight.
Darners interact, by The Dragonfly Whisperer

Non-contact chasing.  The pursued darner escapes with a splash-dunk.
Darners interact with splash-dunk escape, by The Dragonfly Whisperer

Contact interaction.  Darners hold on to one another until they hit the water.
Darners grab one another and fall in the water, by The Dragonfly Whisperer

Extended contact interaction.
Male darners interact big time, by The Dragonfly Whisperer

Males struggling in the water as one attempts to attach to the other.
Male darners struggle in water, by The Dragonfly Whisperer

Tuesday, April 26, 2016

Dragonflying at Tortilla Creek

One of the places we like to dragonfly in Arizona is Tortilla Creek, in the little tourist town of Tortilla Flat.  The town consists of a few small "cowboy"-type businesses along the road.  Here's a picture of the town:



Most of the visitors to Tortilla Flat are probably not even aware of the small creek, Tortilla Creek, just across the street from the town.  Here's a view of the creek:



Everywhere you look when you visit Tortilla Creek you see incredible desert vistas, like the one below.



Dragonflies are out and flying at Tortilla Creek, though not nearly in the numbers that will be seen in about a month.  Even so, we had some good views of Common Green Darners, Flame Skimmers, Roseate Skimmers, Blue Dashers, and a Mexican Forktail.

The Flame Skimmers seemed particularly vibrant.  Here's one that landed right in front of us:



Notice the intense red colors in the wings, including the dark rectangular concentrations (opacities) near the wing bases – an important way to distinguish the Flame Skimmer from the similar Neon Skimmer.  I also like the yellow cross veins near the leading edges of the wings, and the contrast they make with the red colors elsewhere.

A Blue Dasher landed near us, and offered an unusual rear view:



Later, it turned around to give us some more common perspectives:





One other dragonfly gave us some nice close views – a male Roseate Skimmer.  It looked quite young and fresh, with lovely colors, and fairly clean wings.  Here are a few looks at it:





What a treat!

Tortilla Creek may not be well known, and it may be overlooked because of the tourist attractions across the road, but it's a nice place to view birds and dragonflies.

Saturday, April 23, 2016

Plateau Spreadwing at Bosque del Apache

One of the fun things about our recent visit to Bosque del Apache was seeing a new "life ode."

We were driving along the north loop road when we noticed a nice pond with lots of emergent vegetation.  It looked like a good spot to see some damselflies, so we stopped to check it out.  I saw some forktails there, and almost immediately saw some spreadwings as well.  Looking at them through my binoculars I could tell they were a species I wasn't familiar with, so I took some pics for later research.  It turns out they were Plateau Spreadwings, a new odonate for us.

Here's one of the first pics I got of this species.  This individual was some distance away, but my point-and-shoot camera did a pretty good job of getting a shot.



I like the iridescence in the wings.

Here's a closer shot, showing the distinctive thorax stripes – a light-colored stripe on the "shoulder", and a broad brown stripe below it.



As seen in this picture, spreadwings do sometimes perch with their wings held together, though the usual pose is with the wings spread, as in the first picture.