Dragonfly Emergence

Freshly emerged dragonfly

My first real dragonfly outing of the year occurred on May 24, 2021, and as usual, took place at Roger’s Pond in Marlborough Forest. I invited a few friends to join me now that outdoor gatherings can include up to 5 people, and fellow OFNC members Derek and Gerald decided to join me. It was a warm, sunny day, and I hoped to find the usual common skimmers and clubtails, as well as a few uncommon species that I’d seen previously at Marlborough Forest such as the elusive Ebony Boghaunter and Harlequin Darner. I’ve already seen one boghaunter this season, but it’s been a few years since I’ve seen a Harlequin Darner, and the Cedar Grove Nature Trail has been a repeat site for this ode.

We met at 9:30 am, just early enough to get some birding in while waiting for the sun to rise higher in the sky. We had the usual Nashville Warblers, Black-throated Green Warblers, Great Crested Flycatchers, White-throated Sparrows, Veeries, and Yellow-bellied Sapsuckers on the walk in. At the pond itself we had Eastern Kingbirds, a Pied-billed Grebe, Common Yellowthroats and four Ring-necked Ducks. Many dragonflies were already flying along the open trail through the cedar forest, including a few teneral whitefaces and emeralds.

We detoured to the dump, as usual, spotting a perched baskettail along the way. The black colour behind the eyes and shape of the claspers identify it as a Spiny Baskettail. This member of the emerald family is most often confused with the similar-looking Beaverpond Baskettail, which has a similar abdominal pattern and is yellow behind the eyes instead.

Spiny Baskettail

This fresh Four-spotted Skimmer also posed nicely for us out in the open.

Four-spotted Skimmer

In the dump area we took turns flipping over boards and debris, looking for snakes and salamanders resting beneath. We found three garter snakes and three salamanders, including two Eastern Red-backed Salamanders under the same board and a Red Eft under a different board. The red-backed salamanders were the dark form, lacking the red stripe that gives this species its common name.

Eastern Red-backed Salamander

The Red Eft is an Eastern Newt in its terrestrial form. While adult newts can be found swimming in beaver ponds and wetlands, the juvenile form is not aquatic and lives in the forest instead. This is the only part of its life cycle that occurs on land; the eggs are laid in water, and develop into aquatic larva before transforming into the juvenile eft stage.

Red Eft (Eastern Newt)

Once we had finished looking for herps we continued on our way to the pond. An American Emerald circled us briefly before landing in the vegetation. This mature dragonfly has the bright green eyes characteristic of its name.

American Emerald

There were fewer dragonflies patrolling the trails than I would have liked; on previous visits I’d seen numerous baskettails zipping along the sunny gravel path, sometimes 20 feet up in the air. On one memorable occasion, the “baskettail” I was watching flying at about waist-height turned out to be a Harlequin Darner! There were no darners this time, but a fresh Dusky Clubtail perching on the gravel was great to see. These small dragons spend most of their time on the ground, and are usually spotted when disturbed, flying up only to land a short distance away.

Dusky Clubtail

A Silvery Blue was also in the area, nectaring on a wild strawberry blossom.

Silvery Blue

We saw more dragonflies once we reached the grassy area near the pond, mostly Chalk-fronted Corporals and teneral whitefaces. Several more were cruising over the pond, including pairs in tandem and females ovipositing. I looked for an adult whiteface and found this fresh-looking Frosted Whiteface on a blade of grass. It is similar in colour to the Belted Whiteface, which is larger and has red colouring between the wings and at the top of its abdomen, as well as the Chalk-fronted Corporal which has a second white patch at the front of the abdomen just behind the head.

Frosted Whiteface

One of the Chalk-fronted Corporals landed on my net while it was lying on the ground; I photographed it, then found one perching on a flower and photographed that too. You can see its similarity to the Frosted Whiteface in the photo above, as well as the eponymous white spot between the eyes and the wings. The white colour is produced by a waxy coating that develops as the dragonfly matures. Skimmers are well-known for becoming more pruinose as they age, although some dancers and spreadwing damselflies also develop white areas (or become entirely white in the case of the Powdered Dancer) at maturity.

Chalk-fronted Corporal

A few baskettails were zipping along the trail at about shoulder height; I caught one and identified it as a Common Baskettail.  This species is easier to identify than the Beaverpond and Spiny Baskettails as there is a large black patch at the base of the hindwings.  This black patch is much reduced in the other two species, noticeable only in the hand or with a clear photo.  The size of the patch in Common Baskettails is quite variable; in some regions it is quite small, making identification much trickier.  However, in eastern Ontario is it always large, making it a reliable field mark.

Common Baskettail

We spent some time on the metal bridge watching the wildlife in the pool below the small waterfall. There were several large tadpoles in the shallow water, but no frogs; I sometimes see Mink Frogs here in the summer. There were also no clubtails perching on the walls or the branches below the bridge, nor any water snakes basking in the sun. Derek did find one in the grass beyond the bridge, however, though it quickly escaped into the water.

As we headed toward the woods I noticed a dragonfly emerging from its larval shell in the grass right next to the path. Derek and Gerald noticed a few more, and then we started seeing them everywhere! It looked as though we had walked right into the middle of a mass emergence of dragonflies.

Teneral Dragonfly Emerging

Dragonflies begin their lives in the water as eggs laid directly onto the water’s surface or inserted into the vegetation growing close to the shore. It takes about a month for the eggs to hatch, birthing the larvae (also called nymphs) that will eventually become the familiar flying predators in their adult stage. The nymphs spend most of their lives below the water, crawling on the bottom of the pond or river searching for food. Even in the larval stage dragonflies are predators, feeding on worms, snails, leeches, tadpoles, small fish and other insect larvae – including mosquitoes! During this time the nymphs will grow and molt numerous times, increasing in size each time. Most dragonflies spend between one and three years in the nymph stage, although some species take longer than that to mature, and others spend a much shorter time underwater. The Wandering Glider, for example, spends as little as four weeks in the larval stage, which explains its success as a migratory species. In Ottawa the Wandering Glider typically arrives in July and August, then breeds in ponds, wetlands, and in shallow pools along rivers. Because this species is unable to overwinter here, the nymphs transform into dragonflies during the same season and fly south before the cold weather sets in. September is good time to see this species forming swarms with other migratory dragonflies, particularly Common Green Darners, hunting over fields and open pastures.

Dragonfly nymph crawling along the ground

Day length and temperature are the key factors in triggering emergence. Transformation usually takes place very early in the morning, although it was late in the morning when we found several nymphs emerging all along the same section of the trail. We actually saw a nymph walking along the ground looking for a safe spot to complete its transformation. The nymphs leave the water and look for a strong, upright surface such as a plant stem, rock face, tree trunk, or dock support to grip on to. When it finds a suitable spot, the larva hooks its claws into the structure, and takes a short rest.

First the larval shell at the back of the head cracks open, allowing the dragonfly’s head to emerge. The split enlarges down the back, and the head, compressed wings, legs and part of the abdomen are forced out. After another rest, the dragonfly arches backwards and hangs upside down, its emergence only half-complete. During this time, the legs harden, and the dragonfly uses them to grab the larval case in order to pull its abdomen free. Once it has been fully freed from its shell, the abdomen extends to its full length, a fluid called hemolymph (similar to blood) begins to circulate throughout the body and wings, and the wings unfurl and straighten out. The dragonfly rests for at least an hour, letting the wings dry before it flies for the first time.

Dragonflies emerging

A newly emerged dragonfly is called a teneral, and in its first hour or so it lacks the bright colours of the mature adult, appearing pale and translucent. Although some markings are present, it can be difficult to identify them to species at this time (I usually don’t even try). However, most can be identified to family based on the shape of the body, the shape of the claspers, wing shape and venation (once they are fully open), and whether their eyes are widely separated, meet along a broad seam, or meet at a single point. This is something I would like to delve into when I have some time. The thick hindwings and shape of the eyes indicate this is a skimmer, likely a Chalk-fronted Skimmer based on proportions and overall abundance at Roger’s Pond.

Dragonfly emerging

After watching and photographing the teneral dragonflies in the grass, Derek, Gerald and I headed into the woods. It was a bit quieter than usual, and there were no Blue-headed Vireos singing or Ebony Boghaunters flitting through the sun-dappled woods. We reached the stream at the back where we saw a Racket-tailed Emerald resting in a sunny spot, but there were no Ebony Jewelwings and no spiketails flying up and down the stream – perhaps it was still too early. We heard several Ovenbirds, a Scarlet Tanager, a couple of Black-throated Green Warblers, a couple of Black-and-white Warblers and two Golden-crowned Kinglets as we made our way around the pond; although it seemed unusually quiet in some spots, there was plenty of activity in other spots. Best of all, I added a new flower species to my life list when Derek pointed out a Ram’s Head Lady Slipper growing just beyond the edge of the trail:

Ram’s Head Lady Slipper

We also saw a couple of Yellow Lady’s Slippers, while Fringed Polygala (aka Gaywings) were growing everywhere.

Yellow Lady’s Slipper

Fringed Polygala (Gaywings)

I also found a bright male Common Green Darner flying about a sunny clearing. I was thrilled when it landed, and got a few photos. Derek and Gerald had gotten ahead of me, and by the time they returned to see it the Common Green Darner had flown off. Darners don’t perch very often, and I usually have better luck with them in the fall when I scare them up from the long grass in the mornings when it is still cool out.

Common Green Darner

The three of us had a great time exploring Marlborough Forest and discovering its treasures; there were enough birds, bugs, herps, and flowers to keep us all engaged. Even if we didn’t see any of the rarer dragonflies on our visit, the emerging tenerals, the cooperative emeralds, the two salamander species, and the new orchid species definitely made the visit a success!