Thursday, July 26, 2018

A Dazzle of Damselflies

We all know about colorful names for groups of animals—like a murder of crows, or a parliament of owls. For dragonflies and damselflies, a group can be referred to as a "dazzle," which seems like an appropriate name.

At the retention pond described in the previous post we saw a dazzle of damselflies. It was a dazzle both in terms of the number of individuals, and in terms of the number of species, many of which were new to us. Here's a sampling of our damselfly observations at the pond.

First up is the Slender Bluet:

Notice the "slender" black stripe on the side of the thorax.

Along with these bluets we saw another species, the Skimming Bluet:

This species has a broader black stripe on the side of the thorax. It also has a different pattern of blue on the abdomen.

Another new bluet species for us has a name that is basically the definition of an oxymoron—the Orange Bluet:

We also saw a couple of new forktails. Here's the Fragile Forktail:

Not sure where the name comes from on this species, unless it's the "fragile" appearance of the "broken" thorax stripe that looks like an exclamation point. Also note the dark tip of the abdomen.

In addition, we saw Eastern Forktails that are very similar to the Western Forktails we see here in the West:

Notice the solid thorax stripe in this species, and the blue tip on the abdomen.

A surprise species of damselfly was the Powdered Dancer, which so far we have seen only in Arizona:

All in all, we were kept busy identifying the dazzle of damselflies at our hotel.

Thursday, July 12, 2018

Species Spotlight: Eastern Amberwing

In Arizona we have a small, orangish red dragonfly known as the Mexican Amberwing. Its small size and color make it a bit of a wasp mimic—presumably it is left alone by birds who have had unpleasant experiences with wasps in the past. Here's the Mexican Amberwing:

This is a male, as you can see by the hamules projecting downward below segment 2 of the abdomen. Also notice the amber-colored wings, from which the species derives its name.

Now, on the east coast there is also an amberwing dragonfly, but a different species—the Eastern Amberwing. Its color and size are similar to the Mexican Amberwing, though it's a bit darker red. Here's an Eastern Amberwing at the retention pond mentioned in the previous post on the Slaty Skimmer:

In amberwings, males select an appropriate egg-laying site, guard it from intrusions by other males, and escort females to their chosen spot for her approval. The males make dipping motions—touching the water with the tip of their abdomen—in an effort to entice the female to accept the location and begin laying eggs herself. It's an interesting bit of behavior to observe.

When the female isn't going about the business of laying eggs, she's generally perched in nearby vegetation. Here's a female Eastern Amberwing resting in bushes along the shore of the retention pond:

Notice the wing patches, as opposed to the amber wings of the male, and the broad abdomen. Quite a striking dragonfly.

Friday, July 6, 2018

Species Spotlight: Slaty Skimmer

We just returned from a trip to New England, where we saw a lot of dragonflies and damselflies that we don't see here on the west coast. We saw a lot of them right across the street from our hotel, in a little retention pond:

Even the most inconspicuous habitat can be a great place to do some dragonflying. One of the many species we saw there was the Slaty Skimmer, a large dark blue dragonfly with clear wings and black eyes:

Here are a couple more photos of this species:

These dragonflies were just a few miles from historic Lexington, MA, where I lived while I was a post-doc at MIT. Here are a couple views from around the village green in Lexington:

We then traveled just a few miles farther to Cambridge, and the campus of MIT:

A great trip for history, memories, and dragonflies!