Unicorn Clubtail dragonfly (male)

A Unicorn Clubtail dragonfly (Arigomphus villosipes) was photographed near the shoreline of a small pond at an undisclosed location in Fairfax County, Virginia USA.

This individual is a male, as indicated by his terminal appendages. Male dragonflies have three terminal appendages, collectively called “claspers,” that are used to grab and hold female dragonflies during mating: an upper pair of cerci (“superior appendages”); and a lower unpaired epiproct (“inferior appendage”).

For those of you keeping score at home, notice male Unicorn terminal appendages have four points/prongs. Does that mean A. villosipes is an exception to the rule of three terminal appendages for male dragonflies? In a word, no.

05 JUN 2021 | Fairfax County, VA | Unicorn Clubtail (male)

The preceding photo shows a clear view of the male’s terminal appendages. Zoom-in on the full-size version of the photo and you should notice that the epiproct for Unicorn Clubtail is essentially a wide plate with two points/prongs.

Related Resource: Odonate Terminal Appendages – a permanent reference page in my blog featuring identification guides for most of the common species of odonates found in Virginia, and even some of the uncommon to rare species.

Copyright © 2021 Walter Sanford. All rights reserved.

 

Unicorn Clubtail (female terminal appendages)

Two field marks can be used to identify female Unicorn Clubtail dragonflies (Arigomphus villosipes), as shown in the following annotated image: 1) they have two terminal appendages (cerci) rather than three (males); and 2) their hind wings are rounded rather than “indented” (males).

Image used with permission from Bob Blakney.

Editor’s Notes

In my experience, female Unicorn Clubtail dragonflies are seen uncommonly. Sincere thanks to Bob Blakney for kindly granting permission to use his excellent photograph of this uncommon beauty for instructional purposes.

Bob’s photo was taken on 18 May 2012 at Occoquan Bay National Wildlife Refuge using a Canon EOS Rebel T2i digital camera and Tamron AF 18-270mm macro lens.

Copyright © 2018 Walter Sanford. All rights reserved.

Unicorn Clubtail dragonflies (males)

Unicorn Clubtail dragonflies (Arigomphus villosipes) were spotted at several locations along the shoreline of Painted Turtle Pond, Occoquan Bay National Wildlife Refuge, Prince William County, Virginia USA.

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

All of these individuals are males, as indicated by their terminal appendages.

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

The title of the preceding photograph is “The Miracle Shot,” so named because I was able to take one and only one photo of this male before he flew away and the subject is actually in focus!

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

The last photo shows an especially clear view of the male’s terminal appendages. Zoom-in on the photo and you should notice that the epiproct (“inferior appendage”) for Unicorn Clubtail is essentially a wide plate with two prongs.

20 JUN 2017 | OBNWR | Unicorn Clubtail (male)

Copyright © 2017 Walter Sanford. All rights reserved.

Unicorns in unexpected places (Part 2)

I visited Mason Neck West Park, Fairfax County, Virginia USA for the first time on 02 July 2016. There is a small, shallow man-made water retention pond at the park that provides perfect habitat for Unicorn Clubtail dragonflies (Arigomphus villosipes), like the one featured in this photo gallery.

02 JUL 2016 | Mason Neck West Park | Unicorn Clubtail (male)

This individual is a male, as indicated by his unique terminal appendages.

02 JUL 2016 | Mason Neck West Park | Unicorn Clubtail (male)

Mud flats (shown above) and algal mats (shown in the first and last photos) — sounds like a haven Unicorn Clubtails!

02 JUL 2016 | Mason Neck West Park | Unicorn Clubtail (male)

Notice the gas bubbles in the preceding photo. Algal mats release oxygen gas. I wonder whether Unicorn Clubtails enjoy the oxygenated air directly above algal mats, much like football players are refreshed by breathing from an oxygen mask on the sidelines after a long run.

Related Resource: Kevin Munroe, former manager at Huntley Meadows Park, provides good guidance regarding the right habitat for Unicorn Clubtails at his excellent Web site, Dragonflies of Northern Virginia.

Copyright © 2016 Walter Sanford. All rights reserved.

Unicorns in unexpected places (Part 1)

I visited Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA for the first time on 18 June 2016. I found the Calico Pennant dragonflies (Celithemis elisa) that I was looking for at Painted Turtle Pond; I was surprised when I spotted one or more Unicorn Clubtail dragonflies (Arigomphus villosipes) at the same pond!

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

All of the individuals in this gallery are males, as indicated by their unique terminal appendages: the epiproct is a large “plate” that spans both cerci.

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

Like all male clubtail dragonflies, the hind wings of male Unicorn Clubtails are “indented” near the body; this distinctive field marker isn’t shown well by any of the photos in this gallery except the following shot.

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

The juxtaposition of man-made and natural objects is visually appealing in the next photo.

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

18 JUN 2016 | OBNWR | Unicorn Clubtail (male)

Related Resources:

• Calico Pennant dragonflies (males) by Walter Sanford
• Calico Pennant dragonflies (females) by Walter Sanford
• CalicOdonart© by Walter Sanford

Copyright © 2016 Walter Sanford. All rights reserved.

Unicorn Clubtail dragonflies (males)

During a recent photowalk at Huntley Meadows Park, I was reminded that Unicorn Clubtail (Arigomphus villosipes) is one of my favorite species of dragonflies. C’mon, just look at the color of those eyes — you gotta love that!

I was also reminded Unicorn Clubtails are very skittish. Apparently I’m not the only odonate-hunter who noticed.

It commonly rests on wet pond edges, rock and logs, where it can be extremely difficult to approach. Source Credit: Unicorn Clubtail, Odonata Central.

In my experience, you see more Unicorns by letting them come to you rather than by actively looking for them. Find the right habitat for Unicorn Clubtails, sit down and let the game come to you (to use a sports metaphor). Patience is the key. I shot 16 photos during a two-hour period — far fewer shots than a typical photowalk, but hey, it was a beautiful day to sit under a shade tree and wait for one of my favorite dragonflies to appear!

09 JUN 2016 | Huntley Meadows Park | Unicorn Clubtail (male)

The preceding Unicorn Clubtail appears to have a slightly malformed wing and abdomen. Both individuals are males, as indicated by their unique terminal appendages: the epiproct is a large “plate” that spans both cerci.

09 JUN 2016 | Huntley Meadows Park | Unicorn Clubtail (male)

(See a full-size version of the original photo, without annotation.)

Related Resource: Kevin Munroe, former manager at Huntley Meadows Park, provides good guidance regarding the right habitat for Unicorn Clubtails at his excellent Web site, Dragonflies of Northern Virginia.

Copyright © 2016 Walter Sanford. All rights reserved.

Green Heron (eating a fish)

The following brief time-series of photos shows a Green Heron (Butorides virescens) preying upon a small fish in the wetlands at Huntley Meadows Park. Now you see it, …

10 JUN 2015 | Huntley Meadows Park | Green Heron (eating a fish)

…now you don’t! (The bird raised its head in order to swallow the fish.)

10 JUN 2015 | Huntley Meadows Park | Green Heron (eating a fish)

The Backstory

The Green Heron appeared while I was hunting Unicorn Clubtail dragonflies (Arigomphus villosipes). [See related post: Unicorn Clubtail dragonfly (male).] Green Herons can quite skittish. The bird may not have noticed me as I was sitting quietly on my Coleman camp stool, “waiting for the game to come to me” (one of several strategies for stalking odonates).

Copyright © 2016 Walter Sanford. All rights reserved.

Unicorn Clubtail dragonfly (male)

The following dragonfly was spotted on 10 June 2015 during a photowalk alongside the wetlands at Huntley Meadows Park. One look at those widely-separated eyes, …

10 JUN 2015 | Huntley Meadows Park | Unicorn Clubtail (male)

those distinctively-shaped yellow terminal appendages, …

10 JUN 2015 | Huntley Meadows Park | Unicorn Clubtail (male)

plus the profile of this dragonfly perching horizontally on the ground, …

10 JUN 2015 | Huntley Meadows Park | Unicorn Clubtail (male)

and you know this is a male Unicorn Clubtail dragonfly (Arigomphus villosipes). OK, Lilypad Clubtail (Arigomphus furcifer) looks similar to Unicorn Clubtail, but my location in Northern Virginia is far outside the range map for Lilypad Clubtail.

The Backstory: How the Unicorn Clubtail got its name

All members of the Clubtail Family of dragonflies, including Unicorn Clubtail, have widely-separated eyes; the space between the eyes, on top of the head, is called the occiput.

occiput: posteriormost area on top of head, behind vertex and ocelli. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Location 11671). Princeton University Press. Kindle Edition.

Look closely at the full-size version of the following annotated image. Notice there is a small “horn” located in the center of the Unicorn Clubtail’s occiput, hence the first part of its common name. Also notice the tip of its abdomen is slightly club-shaped  — now you know the rest of the story.

10 JUN 2015 | Huntley Meadows Park | Unicorn Clubtail (male)

The occiput and “unicorn horn” are clearly visible in the following photopraphs of a captive Unicorn Clubtail dragonfly.

Photo used with permission from Molly Jacobson.

See more photos by Molly Jacobson at BugGuide.com.

Photo used with permission from Molly Jacobson.

Editor’s Note: Collecting specimens is prohibited at Huntley Meadows Park.

Copyright © 2015 Walter Sanford. All rights reserved.