Tuesday, September 6, 2016

Here Be Dragons

Text by Nancy Partlow©.  All photos taken at Capitol Lake by Nancy Partlow©, unless other wise noted.

In our community there is a magical kingdom.  Towered over by a castle on a hill, it is known by the mundane name of  Capitol Lake, but for the countless creatures  roaming its aqueous realm, it is a cradle of life.  Anyone who has ever peered through a microscopic lens at a drop of pond water has glimpsed this mysterious world. 

As Capitol Lake has slowly filled with sediment over the years, many native species have benefited from its increasingly marsh-like condition.   One group of insects  that has prospered greatly are members of the order Odonata, comprised of dragonflies (Anisoptera) and damselflies (Zygoptera). 
Dancing over the water at Percival Cove, zooming like sunlit fairies above the east lawn at Heritage Park, defending territories and fighting for mates along the  Marathon Park shoreline, dragonflies and damselflies are a consistent summer and autumn-time presence at Capitol Lake.  

Male Western Pondhawk on Heritage Park lawn

Odonates are creatures of freshwater wetlands, and the lake is perfect  habitat for them.  With its shallow depth, muddy bottom and summertime algal mats, the lake is a lentic lagoon and a dragonfly heaven.

I'd previously garnered some limited knowledge about odonates from Janet and Glen, but recently learned a lot more while attending a presentation by well-known expert Dennis Paulson at a Stream Team sponsored event at the WET Center.  Author of Dragonflies and Damselflies of the West, Paulson's comprehensive field guide is filled with fascinating and specific information about these charismatic mega-fauna of the insect world.   I was surprised to learn that beside their great diversity in appearance, each species has differing behaviors for hunting, mating, egg-laying and even perching. 

The language used to describe odonata reflects the way they have captured the human imagination:  dragons and damsels, jewelwings and emeralds, sprites and dancers, even the more explicative skimmers, darners, dashers and hawks.

Damselfly on emergent vegetation at Capitol Lake's middle basin

The immature forms of these insects are called nymphs, although the name hardly reflects the classical definition of the word - they are fierce-looking bugs.  The larval phase comprises the vast majority of the odonate life cycle, which is lived under water.  A nymph's sole purpose in life is to eat and grow through voracious predation upon other aquatic invertebrates. 

After several months and molts, the nymph crawls out of the water  and clamps its legs onto a piece of shoreline vegetation, where it bursts its exoskeleton and emerges into aerial form.  Although I've never seen any of these shed skins called exuviae, there must be many of them hidden in the vegetation around the lake. 

Bright red as an adult, this is an immature Autumn Meadowhawk, just recently emerged
from the lake.  It will gain adult coloration over a period of days or weeks.

Paulson refers to dragonflies as "Natures Rainbows", and they really are.  Their variety of colors and patterns are amazing.  As a wildlife photographer, I love to shoot dragonflies. They're beautiful and make excellent subjects since, unless they're twisting their swivel heads, they perch stock still.  

It's been really fun and interesting trying to discover just how many species of dragonflies breed in Capitol Lake.  I've documented eleven so far, out of the total 33 species recorded for Thurston County as a whole.  Here are their photographs:

Cardinal Meadowhawk near the entrance to the CLIC

Eight-spotted skimmer at the Interpretive Trail
 A Blue-eyed Darner suns in shrubbery along the CLIC trail. This species belongs to the genus Aeshna, whose members are known as Mosaic Darners for the decorative patterns resembling mosaics on their abdomens.

Variegated Meadowhawks mating in a copulation wheel at the CLIC.

Shadow Darner male

Female Western Pondhawk

A male Common Whitetail perching on the ground in the middle of the CLIC
main trail - a typical pose.

 Common Whitetails are highly dimorphic.  This female  was perched on
 a rock near the lower falls at Capitol Lake's south basin.

Blue Dasher male perched on reed canary grass at Marathon Park.

Male Blue Dashers waiting for females at a CLIC pond.

Juvenile male California Darner near south basin of Capitol Lake in May.  According to Paulsen's book, the California Darner is "...almost always (the) first dragonfly to appear in spring, throughout at least (its) northern part of range".

Female California darner ovipositing eggs in an algal mat near CLIC dock. The floating vegetation helps protect the eggs from foraging fish.  

As adults, dragonflies and damselflies are both predator and prey.  The lake which gives them life is also nursery to many other insect species that fly as adults, such as caddisflies, stoneflies, mayflies, midges and mosquitoes, to name a few.  Odonates eat them all. Beetles, flies and Lepidoptera are other common food items, as evidenced by this video I took of a female Western Pondhawk munching on a moth at the Interpretive Center, the scales from its wings floating away in the breeze:

In a terrific and highly unusual photo, local nature photographer Barry Troutman captured a Shadow Darner eating an insect being parasitized by a wasp at the CLIC.

Shadow Darners derive their name from their habit of conducting much of
their activity in the shade.
PHOTO: ©Barry Troutman

Odonates make a good meal for other animals.  Spiders and frogs take their share, and at least 40 species of birds, probably more, are known to consume odonata larvae and/or adults, including the Blue and Green Herons that haunt the shoreline of Capitol Lake.

Despite the name, this is the only Common Green Darner I've seen at Capitol Lake - caught in
a spider web.

Green Heron at Percival Cove.

A Cardinal Meadowhawk perches on a branch near an American Bullfrog near the entrance to the CLIC.  Several Blue Dasher dragonflies also flew near this frog, just out of reach.

I asked Dennis Paulson whether odonates could survive the transition of the lake to an estuary.  Sadly, the answer is no.  Like many magical kingdoms, this one would retreat into legend.  Until such a day comes however, I will visit as often as possible, and allow myself to be willingly spellbound by its mystery and beauty.
Many thanks to Dennis Paulson and Barry Troutman for their help.

Odonata Central records for dragonfly and damselfly species in Thurston County:

Nature's Deadly Drone, from the New York Times:

A female Western Pondhawk finds good camouflage on an Oregon Grape leaf


  1. I look forward to your posts and really loved this one! I have so many dragon flies in my yard and it's wonderful to have this information. Thanks!

  2. What if we made it like 200 years ago?

  3. Oh, this brought back fond memories from when I used to take my mother-in-law for slow walks around Capital Lake when she was sick. It really has filled in since I've last seen it. Are the plans to allow the salt water in still a go?

  4. Katie -- Maybe. This is still an unsettled discussion. Three links (you have to copy and paste)