Explorations of an Ecologist: Search for Sedge Skippers (July, 2018)

In 2018 I made an effort to focus more on Lepidoptera, the butterflies and moths. Butterflies especially became a main interest throughout the summer and I always kept an eye out for different species while completing field work throughout southern Ontario. On a handful of occasions I went out of my way to search for particular species, especially species I had never seen or photographed before.

Spurred on after seeing some of Reuven Martin's recent sightings on iNaturalist, I decided to spend the morning of July 17 searching for sedge skippers at a few different locations found between Hamilton and Guelph.

I arrived at the Turner Tract, a component of the Halton Region Forest, just before 9:00 AM. The morning was warming up and quite a few butterflies were on the wing already as I pulled into the parking lot, including some of "the usuals" - Cabbage White, Northern Pearly-eye, Little Wood-Satyr, Eastern Tiger Swallowtail.

Eastern Tiger Swallowtail - Turner Tract, Halton Regional Forest

Little Wood-Satyr - Turner Tract, Halton Regional Forest

Northern Pearly-eye - Turner Tract, Halton Regional Forest

I had never properly explored the Turner Tract before, and I had certainly never devoted a full morning to searching for insects there. There were several species in particular that I was hoping to encounter. Of primary importance were some "sedge skippers"; that is, several skipper species that find habitat (and foodplants) within sedge meadows and other similar habitats, and which are rarely seen outside of these habitats. Mulberry Wing and Black Dash in particular I had never seen before, and both could be found in some of the wetlands at the Turner Tract. I was also hoping to find Appalachian Brown, a species I had seen before but never photographed. The sedge skippers in particular have a relatively short flight season and I wanted to observe them before it was too late in the summer.

As I walked along a forest path south through the Turner Tract I got on my first Eyed Brown, a similar species to the Appalachian Brown but one which is usually a bit more common, and found in more open wetland habitats.

Eyed Brown - Turner Tract, Halton Regional Forest

Butterflies were not the only insects vying for my attention; several different odonates also flew past, the warm morning sun powering them up.

Enallagma Bluet sp. - Turner Tract, Halton Regional Forest

Canada Darner - Turner Tract, Halton Regional Forest

Slender Spreadwing - Turner Tract, Halton Regional Forest

My plan of attack was to hike through several of the "sedgiest" looking wetlands at the Turner Tract in hopes of turning up my main quarry. But even before getting to the wetlands I kept getting distracted by insects. A few Banded Hairstreaks were a welcome sight; this species may be locally common at times, but it only flies for a brief period in the summer, making it a treat whenever I come across a few individuals.

Banded Hairstreak - Turner Tract, Halton Regional Forest

Skippers adorned many of the trailside plants wherever there were sunny patches. The vast majority were Dun Skippers, but I also singled out a few Northern Broken-Dash.

Northern Broken-Dash - Turner Tract, Halton Regional Forest

Dun Skipper - Turner Tract, Halton Regional Forest

Along the forest trail I added more species to the day list - Red-spotted Admiral, Northern Crescent, Viceroy, Least Skipper and Monarch.

Red-spotted Admiral - Turner Tract, Halton Regional Forest

Northern Crescent - Turner Tract, Halton Regional Forest

I hadn't yet arrived at my first wetland to search and I was still deep in the forest when one of the Lethe species went past and eventually settled on a unit branch. An Appalachian Brown! Unfortunately it was quite skittish and this was about the best I could do for photos, but it was fun to finally have a chance to study one for the first time in several years. Compared to the Eyed Brown, the Appalachian Brown has less jagged postmedian lines on the underside of the forewings and hindwings, while the middle two eyespots on the forewing are usually a bit smaller than the outer spots. It prefers more wooded habitats than the Eyed Brown, though both species overlap in habitat near the borders of wetland and woodland.

Appalachian Brown - Turner Tract, Halton Regional Forest

I found a nice spot to enter the first sedge meadow and began searching. The morning was quite warm by this time, and sedge meadows seem to collect the heat and humidity, but fortunately the mosquitoes were not too bad at all. Many additional Eyed Browns appeared but sedge skippers were being trickier to find than I expected. The few skippers I did see all happened to be Dun Skippers.

Eyed Brown - Turner Tract, Halton Regional Forest

After an hour or so of searching, I finally ran into my first sedge skipper. It appeared to be a Mulberry Wing when I first saw it, but it perched with its wings spread open, making it impossible to see the underside of the wings to clinch the ID. I only managed a few photos before it took off and disappeared further into the wetland.

Possible Mulberry Wing - Turner Tract, Halton Regional Forest

Eventually I gave up my search, feeling a little disheartened as I made my way back to the forest trails to hike to the next wetland. Along the way, a few more interesting insects made appearances.

Hummingbird Clearwing - Turner Tract, Halton Regional Forest

Gray Comma - Turner Tract, Halton Regional Forest

Mourning Cloak - Turner Tract, Halton Regional Forest

Azure sp. (Celastrina) - Turner Tract, Halton Regional Forest

By now it was the early afternoon and the day was quite warm. Fortunately the butterflies were still fluttering-by, and the second wetland proved to be much more successful.

A few stunning Baltimore Checkerspots were acting territorial in this wetland, frequently duelling with each other in mid-air. It had been years since I had last seen a Baltimore Checkerspot. They rely primarily on Turtlehead (Chelone glabra) as their foodplant, and only occur in wet meadows where that species grows.

Baltimore Checkerspot - Turner Tract, Halton Regional Forest

I walked a loop of the perimeter of the wetland, spotting a number of butterfly species along the way, while a Yellow-billed Cuckoo flew into a small tree and began vocalizing. I was focused on a large patch of Swamp Milkweed when a medium-sized skipper with a distinctive wing-pattern appeared. A Black Dash!

Black Dash - Turner Tract, Halton Regional Forest

I ended up finding several Black Dashes in the wetland and enjoyed photographing them. Black Dashes can be identified from underneath by their reddish brown base colour with a distinctively shaped lighter band on the hindwing.

Black Dash - Turner Tract, Halton Regional Forest

A Mustard White was a welcome find at the edge of the marsh. Superficially similar to the abundant and introduced Cabbage White, the Mustard White has clean white wings with prominent veins, finding habitat in rich deciduous forest, which is one of the few habitats that Cabbage Whites are not usually abundant. I have not seen too many Mustard Whites and this was the first one that I managed to photograph in southern Ontario.

Mustard White - Turner Tract, Halton Regional Forest

Happy with my success at the Turner Tract, I snapped a few more photos of a Baltimore Checkerspot and a Twelve-spotted Skimmer and then made my way back to the car, photographing an obliging Clymene Moth on the way. Even though I had not been able to confirm a Mulberry Wing, I lucked out with encounters with Black Dash, Appalachian Brown, Baltimore Checkerspots and a bonus Mustard White. It had been a great day!

Baltimore Checkerspot - Turner Tract, Halton Regional Forest

Twelve-spotted Skimmer - Turner Tract, Halton Regional Forest

Clymene Moth - Turner Tract, Halton Regional Forest

By now it was nearing 2:00 PM, meaning I still had time to check out one more spot. I targeted an area near Puslinch called the Fletcher Creek Ecological Preserve. I had never been there before but noticed on iNaturalist that there had been a number of recent records of sedge skippers from there.

Near the northwest corner of the reserve I parked on the side of Concession Road 7, as a number of Tufted Vetch, Spotted Joe-Pye Weed and Swamp Milkweed were flowering near the edge of a small watercourse. This proved to be "the spot" and I quickly spotted a Mulberry Wing nectaring on some Tufted Vetch!

Mulberry Wing - Fletcher Creek Ecological Preserve, Wellington County

Along with several Mulberry Wings there were good numbers of Broad-winged Skippers (another species of "sedge skipper") and a few Black Dashes thrown in for good measure. The Mulberry Wing has a very distinctive airplane-shaped mark on the underside of its hindwing.

Broad-winged Skipper (left) and Mulberry Wing (right) - Fletcher Creek Ecological Preserve, Wellington County

Black Dash - Fletcher Creek Ecological Preserve, Wellington County

Broad-winged Skipper - Fletcher Creek Ecological Preserve, Wellington County

Even a worn Baltimore Checkerspot was in attendance. There was a flurry of butterfly activity, though the strong breeze made photography a little challenging as the flowers they were nectaring on would not stop moving!