Thursday, June 7, 2012

Anacortes – The New Emerald City?

It's well known that Seattle goes by the nickname "The Emerald City," but yesterday Anacortes had reason to use that name as well.  It was home to at least two American Emeralds, a small dark dragonfly with beautiful green eyes.  Here are a couple photos:

American Emerald, male.  Notice the single white ring hear the base of the abdomen.  Ringed Emeralds have white rings at the base of each segment along the abdomen, and Mountain Emeralds have no white rings at all.

American Emerald, male.  Notice the shape of the abdomen – it starts narrow, widens out, and then narrows again near the tip.

The emeralds were at Cranberry Lake, where I saw my first dragonflies in Washington State this year.  In addition to the emeralds, there were several Four-spotted Skimmers, and a dozen or more California Darners.

The emeralds are about the same size as Four-spotted Skimmers, but they are much darker and skinnier in flight.  Also, they look "deep chested" – that is, the thorax seems oversized in comparison with the rest of the body.  When they fly toward you their eyes give an unmistakable flash of green.

The common emeralds in our area are the American Emerald, the Ringed Emerald, and the Mountain Emerald.  The American Emerald is distinguished by having a single white ring near the base of the abdomen, as you can see in the photos above, whereas the Ringed Emerald has white rings at the base of each segment of the abdomen.  See the following link for a look at a Ringed Emerald:

In contrast, the Mountain Emerald has no white rings on the abdomen, but instead has golden stripes on the sides of the thorax.

As you can see in these photos, American Emeralds like to perch on the ground.  They have a rather low perching index (perhaps around 50%), but with patience you can follow them until they land and get a great view.  Seeing those eyes close up is worth the wait.

No comments:

Post a Comment