Saturday, September 12, 2020

Dragonflies of August

The first cold front that came through on Wednesday (September 9). The break from the heat made it easier for me to look back on August as part of the recent past, and not just part of the unending pandemic-induced present. It finally got cooler! That means summer is finally passing, right? I wanted to make this post an overview of all my nature observations in August, but I soon realized there were more than enough dragonfly observations for a long post. So here they are, an overview of my August dragonfly observations on Lake Creek Trail in northwest Austin (Williamson County).

Dragonflies can be found year-round in small numbers in central Texas, but their numbers peak in the summer. They love the heat and their activity and detectability increase in middle morning as bird activity deceases. So it can come naturally for birders who get out early on an August morning to switch from watching birds to watching dragonflies as the morning progresses. Numbers and diversity of dragonflies on Lake Creek Trail seemed lower this summer, but here some favorites I found.

In early August Halloween Pennants were common, perched at the top of bare twigs or old cone flowers in the low grassland on the east end of the trail. You can see the bright red spots near the ends of the wings called pterostigmas on this male:

Halloween Pennant - 2

The dragonfly below is an Eastern Amberwing. It's the smallest dragonfly in north America, only a little over 1 inch long. It's superficially similar to the Halloween Pennant above but it's so much smaller. It was in the same grasslands area.

Eastern Amberwing - 1 - 1

Along the banks of Lake Creek, the most common dragonfly was usually the Comanche Skimmer. The males are blue with white faces and bi-colored pterostigmas. This one was perched on some reeds by the creek where it goes through the Town and Country playing fields:

Comanche Skimmer - 2

The most common dragonfly both near and far from the creek has been the Eastern Ponhawk. the males are also blue, but with green faces. The females are green and black. Here's a female near the last dam on the creek:

Eastern Pondhawk

Wandering Gliders were common in August (and still are now) but they are hard to photograph since they are "fliers." They hunt on-the-wing instead of from a perch. When they do rarely perch during the daytime, it's to rest. I got a few photo ops of perched Wandering Gliders, and my best was probably this bright yellow male. See how it hangs vertically compared to the other dragonflies which perch more horizontally:

Wandering Glider - 3

Another common "flier" species in August is Common Green Darner. This is also the largest dragonfly that commonly occurs here. You can see the bright blue abdomens of the mature males as they fly by. Here's one that briefly perched in the reeds near the last dam on the creek:

Common Green Darner

Here are some of the less common species I found in August on the trail.

Gray-waisted Skimmers are a small elegant perching dragonfly that is present some years in the woods on the west end of the trail. I only found one male and one female this summer, at one spot in the woods off the trail. Here's the female:

Gray-waisted Skimmer

Red Saddlebags and Black Saddlebags are two common species on the trail. (The "saddlebags" part of their name comes from the large dark patches on their hind-wings shaped sort of like saddlebags on a horse.) I wasn't very successful in photographing them last month. (They are both "fliers.") But I was surprised one morning near the last dam when what I thought was a perched Red Saddlebags turned out to be the much less common Striped Saddlebags. You can see the strips on its thorax:

Striped Saddlebags - 1 - 1

My favorite dragonfly observation of August was this female Great Blue Skimmer. I've only seen a handful of these on the trail, and I've never seen a bright blue male. This female posed for me in almost perfect conditions. It was in the tall grass on the west end of the trail:

Great Blue Skimmer - 2

Many dragonflies are migratory, including Wandering Gliders and Common Green Darners pictured above. We don't know a lot about dragonfly migration yet. But in the fall there are sometimes large dragonfly migration events, with hundreds or thousands of individuals moving south in the early morning or early evening. I was lucky to see some minor movements last month just sitting in my backyard in the morning or evening. I would start to notice that dragonflies would be flying over the trees mostly in the same southeast direction. See if you can notice movements like this as the fall progresses!

Here are all of my neighborhood photos from August on Flickr. Other nature highlights included a family of Mississippi Kites in my yard, and the start of fall bird migration, with a few south-bound songbirds showing up. I hope to make a separate post about these soon.


cricket said...

I did not know Wandering Gliders ever perched, let alone that they do so vertically!

Mikael Behrens said...

Yes! Most of the "flier" species hang vertically when they perch. And the "perchers" perch mostly horizontal, ready to dash off after flying prey!

Chip B said...

Very well shot Mikael. I'm impressed with the Leica/Olympus combo.

Monica Solomon said...

Thank you so much. I really enjoy the dragonflies and your photos are wonderful

Birdability said...

Thanks, Mikael. I really enjoy your photos and your commentary.

Unknown said...

We've seen so many this year in our backyard. Thanks for posting this!

Pam and Mike said...

Mikael, Thanks so much. Mike and I really miss getting to go on your walks since we have moved. Really look forward to seeing what jewels you have had in your piece of paradise.
Pam and Mike Goolsby