Saturday, July 28, 2012

Dragonfly Hunt at Lake Monticello

Calico Pennant
Fresh from attending the Dragonfly Society of the Americas meeting in May, my husband and I were heading on a kayak trip.  We found out after we were all packed up and on the road that due to unforeseen circumstances (the trip leaders had just gotten home from the previous days' trip!) the Sunday trip was cancelled.  I suggested we head to Lake Monticello in Fairfield County.  Lake Monticello is a man-made lake created to support the nuclear power plant at Jenkinsville.  One portion called the "Recreation Lake" is designated for water craft with no motors.  We've had several good days of wildlife viewing there in the past.  But today, I was thinking about dragonflies.  I remembered that Fairfield County was one of the ones in SC with very few documented species.

As we unloaded the boats it was hard not to notice the birds in the area:  a couple of osprey soared over the dam, some northern rough-winged swallows looked like they might be gathering nest material and the red-winged blackbirds were singing among the tall grasses near the water's edge.  We also saw one solitary sandpiper running along the shore before we put in.

Once in the water, we stayed near the shore both because it was windy as well as because that was where I thought the best dragonfly and damselfly viewing would be.  This was true -- we didn't have to go far to begin to see species.  Now photographing them was another matter!

Currently, dragonfly species are documented on a database called Odonata Central.  Unlike eBird, you must submit photos of species you report and those are confirmed by an expert after submission.  So it is really important to get the best photos you can -- from several angles if possible. 

The first dragonfly I found was this teneral Banded Pennant clinging to a blade of grass.

Banded Pennant - teneral

A teneral dragonfly is a very new adult.  Often, their colors are more muted than fully mature specimens. When they have just emerged from their larval state, they are vulnerable until they have taken their first flight.  I was not sure if this specimen already had some damage, but I definitely did not want to inflict more.  However, it was difficult to keep my boat from crashing into the grass or sailing off while I was trying to get the camera ready.  This was probably the 12th photo I took (thank goodness for digital!) where I decided to hold the grass steady to try to keep us all somewhat still.  This specimen might be a female or an immature male based on the yellow spots on the abdomen.  In males the abdomen will become entirely black as they mature.  A Banded Pennant has a fairly distinctive pattern on the wings that when combined with body shape and color make it easy to confirm.  I now know that for this species, you don't have to have a lot of different photos and views. 

Unknown Clubtail

There are species, however, that are much more difficult to confirm.  This clubtail is an example.  This guy cooperatively sat on my boat  for some time and I felt sure I was able to get a photo that would sufficiently ID him.  You can tell that he is a clubtail (Gomphidae) because his eyes do not touch and the last abdominal segments widen before the tip into a sort of club.  I studied Giff Beaton's book, Dragonflies & Damselflies of Georgia and the Southeast for quite a while and decided this specimen is likely a Lancet Clubtail.  However, the Ashy Clubtail is very similar but more dull, and the Cypress Clubtail is so similar that only viewing the male appendages under magnification can confirm which is which.  So when I submitted this photo to Odonata Central it was reviewed and left as "Pending" (essentially unable to be confirmed).

The need for such careful identification of some species is the reason most who study dragonflies carry nets in the field.  There are some species that you simply must have in hand to identify.  Many practice a careful kind of "catch and release".  Others store and retain specimens for later study.  I have purchased a net, but have not become proficient with its use yet.  Many more hours of practice are needed.

In addition to dragonflies, I was able to find and document several species of damselflies.  Since I've been telling people I'm studying dragonflies, the most common question I get is: "What's the difference between a dragonfly and a damselfly?"  Dragonfly is often used generically for both, but technically these are two separate sub-orders:  Zygoptera and Anisoptera.  Damselflies are in Zygoptera which means equal wings (the front and hind wings are roughly the same size and shape).  Anisopetera means unequal wings.  These are the dragonflies whose forewings and hindwings differ in shape.

Fragile Forktail

The Fragile Forktail is one of the damselflies I spotted at Lake Monticello and it has rapidly become one of my favorites because it does have a characteristic that makes it relatively easy to identify:  a shoulder stripe in the shape of an exclamation point (it is in the lighter shade of green in this photo).  Once you learn how many damselflies are alike and how carefully you have to study them, you really appreciate the ones with a clear difference.  Luckily, these seem to be a common species in South Carolina and easy to find if you scan for movement near the edge of the water.  The length of this species is about 1 inch.

All in all on this day, we were able to get good photos of enough species to almost double the odonata records for Fairfield County.  There had been no damselflies documented at all.  It takes patience to find species and get sufficient photos, but it is also satisfying to know that you are contributing to the body of what is known about these amazing creatures.

1 comment:

Stephina Suzzane said...

I've been working on it all season and trying my shot better and Ellen Craven, who I played together with on travel team, she heard me yelling 'top of box' and she played a great ball back and I went for it.

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