Species Spotlight: Spot-winged Glider

Well, it seems only appropriate that the Spot-winged Glider should have a turn in the "spot"-light.

Betsy and I made a number of observations of this species on our recent trip to the East coast. Our first sightings were at the Back Bay Wildlife Refuge near Virginia Beach, VA. We saw many of these dragonflies at the refuge, where they were immediately identifiable by the small dark spots next to the abdomen on the hindwings. Here's a look at one:



The dark spots are small, but they're clearly visible in flight as the dragonflies zip by. Here's another look at the spots:



At Back Bay, we saw a pair in tandem dipping repeatedly as the female deposited eggs in a small mud puddle, maybe 6 feet square. The next day we returned to the same spot, to look for interesting birds, and noticed that the puddle had dried up. This species is known for laying eggs in temporary bodies of water that are free of fish, and small puddles are one example. Presumably, the eggs can survive out of water until Fall rains return to fill the puddles for a longer period of time—or perhaps this is just one example of egg laying in inappropriate locations that simply won't support the next generation.

Another example of inappropriate egg laying was observed on our second trip, this time to Cape Cod, where we again saw Spot-winged Gliders. In this case, we observed female Spot-winged Gliders laying eggs repeatedly on the hood of cars in the parking lot of a wildlife refuge. This is know behavior for this species. Presumably, the polarized reflected light from the car hoods make the females treat the surfaces as being pools of water. We saw the females make many dips onto the hoods, and a number of eggs were deposited. Here's a photo of one of the hoods. The tiny yellow spots are Spot-winged Glider eggs:



Here's a closer look at one cluster of eggs:



The dragonflies were so determined to lay eggs on the cars that they were even doing so as the cars moved about in the parking lot. I've read that in the Middle East they like to lay eggs in pools of oil, which apparently give even stronger reflections of polarized light. Lots of strange things are going on out there in our world.

Dragonflies and a Presentation in Winthrop

Betsy and I gave a dragonfly presentation last week at the Merc Playhouse in Twisp, near Winthrop, WA, for the Methow Conservancy. The presentation was well attended, and there were lots of good questions—it was a lot of fun. Thanks to all who came out on a smoky evening to learn more about dragonflies.

The next day, we led a field trip to Beaver Pond, near Sun Mountain Lodge. Later in the day we also stopped by Twin Lakes for a few additional species.

Here's a view of Beaver Pond from the wooden footbridge.

The view from the wooden footbridge at Beaver Pond near Sun Mountain Lodge in Winthrop, WA. This is a good place to see lots of dragonflies, and to watch for the splash-dunk/spin-dry behavior. We saw a few examples during our field trip.

This is the other end of Beaver Pond. Notice the darner flying by at the top of the photo.



We saw lots of darners flying back and forth over the water. A few meadowhawks were in the bushes along the shoreline, in addition to many damselflies.

We were also fortunate to see the splash-dunk/spin-dry behavior a couple times. The footbridge is a great place to see the behavior—in fact, the spin-dry at this location is performed at eye level, making it particularly easy to observe. We had a couple good views of this rare phenomenon.

Here's our species list for the field trip:

Damselflies
Spotted Spreadwing
Northern/Boreal Bluet
Tule Bluet
Pacific Forktail
Western Forktail

Dragonflies
Paddle-tailed Darner (Happy Face)
Canada Darner
Blue-eyed Darner
Variable Darner
Striped Meadowhawk
White-faced Meadowhawk
Black Meadowhawk
Cherry-faced Meadowhawk
Eight-spotted Skimmer

At the end of the trip we encountered an interesting situation at Twin Lakes. It was a female damselfly with the abdomen of a male attached to her. What likely happened is that a dragonfly at the lake captured a pair of damselflies flying together in tandem. It then snipped off the thorax of the male for a nice snack, dropping the rest of the pair into the vegetation. Here's a detailed discussion of a similar event observed at Cranberry Lake:

http://thedragonflywhisperer.blogspot.com/2012/09/15-damselflies-darner-predation-in.html

This was truly a damsel in distress, but one of our participants kindly removed the male's abdomen, freeing the female to continue her life unencumbered.

Here's the poster advertising the talk:

The Dark Side Of Blue Dashers

On a recent trip back east, we noticed that the Blue Dashers there often have quite a bit of wing coloration—specifically, dark patches near the tip. Here are a couple examples:





In our area we only see wing coloration near the base of the wings. Interesting variability in this species.

The Dot-tailed Whiteface Does A Body Slam

On a recent trip to Heart Lake here in Anacortes, I observed a new behavior exhibited by the Dot-tailed Whiteface. Here's a picture of an individual of this species from Heart Lake:



Notice the chalk-white face, black eyes, clear wings, and black body with a yellow dot near the tip of the abdomen. This is surely one of the easiest IDs to make in dragonflying.

Getting back to the behavior, I was taking a video of general dragonfly activity at the lake. When I got home and viewed the video on the computer I noticed some unusual movement in the lower right corner. On closer inspection, I saw that a bluet was harassing a Dot-tailed Whiteface, eventually grabbing its abdomen. The whiteface immediately did a spin move—similar to what dragonflies do in a spin-dry, only in this case it was "shedding" the damselfly rather than water.

Here's a video clip showing the body slam. It's grainy because it's an enlargement of the lower right corner of the full video:

You can see the full video at the following link:

https://www.youtube.com/watch?v=QuY34erRHpY

Fascinating behavior, where the dragonfly adapts one behavior—spin-dry to shed water—to another ver different situation—spin-dry to shed a damselfly.

Find out more about the splash-dunk/spin-dry behavior, as well as about the Dot-tailed Whiteface, in my new field guide, Common dragonflies and Damselflies of the Pacific Coast. You can find the book at the following link:

https://www.amazon.com/gp/product/1934199265/ref=s9u_simh_gw_i1?ie=UTF8&fpl=fresh&pd_rd_i=1934199265&pd_rd_r=4Q8FNWQMZKPZ7GYWQB31&pd_rd_w=c79uB&pd_rd_wg=lb3xg&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=&pf_rd_r=038QHD1N13Z2D7NWAP1Q&pf_rd_t=36701&pf_rd_p=1cf9d009-399c-49e1-901a-7b8786e59436&pf_rd_i=desktop

You never know when a trip to the field will result in new behavior.