Flora and fauna of the Athens County area, and occasionally habitats outside Ohio. Subject matter will consist of both interpretive material and taxonomic issues in plant and animal identification.

Thursday, March 20, 2014

Skipper Butterflies

Whenever I do a large post on a particular group of plants or animals, I always seem to start with a disclaimer. Not all of the skippers are illustrated here. I simply haven't seen all the species in Ohio. But in the interest of keeping my posts going, here are a few.

Lepidoptera are the Butterflies & Moths. There are those who like to add AND the Skippers. Like Hymenoptera, the bees, wasps, ants, and Sawflies. Sawflies are a type of wasp, but with fat bodies. Same goes for the Skippers. They are a "type" of butterfly, but have fatter bodies. They are extremely fast fliers, which means they have strong wing muscles. As any collector can tell you, pinning and spreading their wings is quite a challenge. Another difference is many species sit with their upper wings folded, and the hindwings open.

Also look at their antennae. Most don't end in a club. They are swollen, but then form a fine tip. These tips are often curved on many species. There are about 50 different Skippers in Ohio. Over 40 of them are known to breed here. The others are strays, having been recorded only once or twice in the state.

I have collected over 30 of them found in Ohio. My goal now is to photograph them. I could expand this post and illustrate mounted specimens, but as I have been fond of saying, a post that size could go on forever. This is the most difficult family of Butterflies to identify by photos, many of them you need to have 'in hand' to examine fine details. For now I will stick to live shots, but hope to add more on the subject at a later date.

One of our largest and most common species is the Silver-spotted Skipper, Epargyreus clarus. If all you see is the inside of the wings, it could be mistaken for the slightly smaller Golden-banded Skipper.


A quick look at the backside, and the silvery-white patch in the middle of the wing is unmistakable. This species is found statewide.


At the other end of the size spectrum is our smallest species, the Least Skipper, Ancyloxypha numitor. It has a longer body than other skippers. The wings are all orange on the outside, and darker orange inside. These are weak fliers when compared to other members of the family, so look for them in low vegetation near the ground.

The Least Skipper ranges all the way down to Florida, where this shot was taken. It's nectaring on Lippia flowers. In Florida there is a similar looking species called the Skipperling. That species has a broad white band across the back of the hindwing.

Some of the earliest skippers to come out in the spring are the Dusky Wings. These are medium sized skippers that are brown with mottled hindwings. That pretty much describes all of them, as they look quite alike.

One of the things I use to narrow down the species is the gray line bordered by black dots. That makes this either the Dreamy Dusky Wing, Erynnis icelus, or the Sleepy Dusky Wing, Erynnis brizo. Sleepy tends to be found more in dry oak woods, while Dreamy prefers Willows and Poplars and a wetter area. Dreamy usually has much larger gray patches on the forewings than you see here. To me this looks more like a Sleepy, but I have been told this photo is a Dreamy, so I defer to the experts.


Another group of similar looking species include Juvenal's, Horace's, and Mottled Dusky Wings. These  can be recognized by the silvery white spots in the upper wings. The Mottled Dusky Wing, mostly found in southern Ohio, has large black 'mottling' on the hindwings.

These are photos of Juvenal's Dusky Wing, Erynnis juvenalis. Notice the two light spots on the hindwing. If these are present on the back of the wing, it's Juvenal's, if absent, it's Horace's Dusky Wing. Also, Juvenal's flies only in the spring months. Horace's can be found all summer. Another thing this group of skippers have in common, the margin of the wing appears indented along the top. Dusky Wings commonly bask on the ground in open sunlight.

Here are the two spots I mentioned. Yes, the specimen is posed, but I wanted to make sure you saw the spots I was referring to.

Wild Indigo Dusky Wing, Erynnis baptisiae. I found this species flying among the Blue and White False Indigos (Baptisia) on our prairie. I recognize this species by looking for the several large silvery white cells in the upper part of the forewing, followed by a couple tannish-brown rectangle cells below.

Historically, this species was restricted to fields and open prairies. The flower Crown Vetch, Coronilla varia, has been planted throughout the state, and has broadened the range of this butterfly. Crown Vetch is now the primary host for the caterpillars.


This is the Northern Cloudy Wing, Thorybes pylades. Sometimes mistaken for a Dusky Wing, they lack the mottling of that group. Essentially the wings are a chocolate brown. Look for two rows of 3-4 small white dots coming down from the wing margin. The center of the wing will contain one or two other silvery white spots. The markings are the same on the back. In the similar Southern Cloudy Wing, those little spots are large broad rectangles. Look for this flying along forest edges.


The Little Glassy Wing, Pompeius verna, is one of the smaller, rapid flying skippers. Dark like the Cloudy Wing, it has only one row of small spots coming down from the wing margin. The center spots of the Cloudy Wing are highly separated, in the Glassy Wing they are crowded together. The spots are somewhat translucent.


The backside shows the same spot arrangement, but the hindwing often hides them. The hindwing may or may not show faint spots. Look for the white spot behind the swollen portion of the antennae.

Common Sooty Wing, Pholisora catullus. This butterfly is all black. Look for the S shaped row of white spots. A few pin hole sized spots may also be present. On females, the spots are more obvious. The speckled white head may also aid in identification. These are found state wide in open fields.



Broken-dash Skippers. The top one is the Northern Broken-dash, Wallengrenia egeremet. South of Ohio is the Southern Broken-dash, W. otho. These are orangish-red butterflies when looking from behind. The hindwings have a semi-circular pattern of yellow spots. The forewings are edged in gray.

The inside usually has at least one large light colored rectangular spot. The arrow indicates where the common name comes from. There is a black line near the base of the hindwing. It appears busted in half, like a broken bat. Click on the photo for a closer look. This is a summer species found statewide.


The Sachem Skipper, Atalopedes campestris. Look for white squares randomly placed on the backside. The largest one, out near the edge of the forewing, is transparent. This is especially noticeable on these females. She also has a transparent spot on the inside, right behind a black dash. Both sexes have a black mark inside, but it is not broken like the previous species. In males, the black mark (or stigma) may be square, and half black, half gray. Look for these in open fields, as the  caterpillars are grass feeders.

Here is another species I find difficult to identify when looking at the inside of the wings. It's the Peck's Skipper, Polites peckius. They too have a black dash inside the forewings. It is shaped like a skinny S, but not visible when they hold their wings like this.



I posted several of these because the underside is so distinct. Two semi-circular rows of yellow spots. The inside one narrow, the outside patch broad. It's one of the most common of our small skippers, having been found in every county.

Inside and outside wings.


Zabulon Skipper, Poanes zabulon. A very sexually dimorphic species. Male above, female below. The rusty colored female is recognized by the thin white streak at the top of the hindwing.

The male has one big round yellow patch interspersed with dark spots. This yellow patch fills up most of the hindwing.

Here is Sachem, Peck's, and Zabulon side by side. If you are specifically in the field to identify skippers, and it takes too long to sort through pages in a book, simply create your own field guide. Make plates of species you have identified and print them out. It can serve as a quick reference guide.



Flying low to the ground is the Hobomok Skipper, Poanes hobomok. It prefers sunny openings in woodland forests. Both the front and hind wing show large solid patches of yellow-orange. It most closely resembles zabulon, but without the pepper marks in the wings.


There is one skipper called the Whirlabout. That's what all of these do. When disturbed they whirl in a very erratic pattern. First they are flying in front of you, and suddenly they disappear.  Don't worry, just turn around, they probably landed six feet behind you.

Tuesday, February 25, 2014

Warblers of Ash Cave State Park

Ash Cave is one of the Hocking Hills State Parks located in Hocking County Ohio. It's known for its geological formations and a spectacular waterfall. The Hocking Hills contain glacial remnant forests usually found much further north. The gorge is full of towering Tuliptree, Liriodendron tulipifera, Eastern Hemlock, Tsuga canadensis, Sycamore, Platanus occidentalis, American Beech, Fagus grandifolia, and Sugar Maple, Acer saccharum. The rim is blanketed with Hemlock trees, and the upper slopes are a mix of Oak and Hickory. I've recorded 70 species of woody plants and nearly 100 spring wildflowers at Ash Cave.

                               Black and White Warbler
While working at the park back in 1980, I noticed a high number of Northern Parula Warblers, Setophaga americana, and Black-throated Green Warblers, Setophaga virens. They weren't just passing through, but apparently nesting. These two species are few to absent in many of the other forest types in the surrounding counties, at least in the numbers found here. I wondered what other species might be present, so I decided to make a count of all the warblers found at Ash Cave.

                                Black-throated Green Warbler
Surveys were conducted in 1980 and again in 1981 between 7:00 and 9:00am. The route included the picnic area, gorge trail, rim trail, and part of the Buckeye trail behind the falls. Birds were recorded by both sight and song. Soon after the project I moved out of state, and never did anything with the data.

                                Canada Warbler
Years later I returned to the area and asked Pat Quackenbush, naturalist for Old Man's Cave and surrounding parks, if he would like to participate in repeating the surveys. I wanted to see if the diversity had changed over the 25 years. We gathered data using the same methods as before. With both of us busy with other projects, we hem-hawed on what to do with the results. Before we knew it, another 5 years had passed. So in 2013, we did it again. Now we can compare over a 30 year period.

                                Common Yellowthroat
19 species of warblers were recorded over the five survey years. The most frequently encountered species include, Black-throated Green, Parula, Ovenbird, Louisiana Waterthrush, Yellow-throated, Black and White, Hooded, and Worm-eating.

Those that were occasional or uncommon were Pine, Yellow, Blue-winged, Blackburnian, Cerulean, Canada, Kentucky, Common Yellowthroat, Prothonotary, American Redstart, and Tennessee.

                                Hooded Warbler
The three most common species were Black-throated Green, Parula, and Ovenbird, Seiurus aurocapillus. If we were to compare 1980-81 to 2005-06 & 2013, their numbers have declined by over 50%. The Cerulean Warbler, Setophaga cerulea, has gained a lot attention, showing the most rapid decline of all in North America. In 1980-81 there were 14 records. In 2005-06 we saw 2, and last year zero. Cerulean, like the Kentucky Warbler, prefer broken canopies, and a multi-layered understory. With the maturity of Ash Cave forests, it may no longer be favorable to these species. (Jim McCormac personal comm.)

                                Kentucky Warbler
There were four birds in particular that showed the most drastic results. Yellow-throated Warbler, Setophaga dominica, and Kentucky Warbler, Geothlypis formosa dropped by 93%. Worm-eating Warbler, Helmitheros vermivorum, by 90%, and Hooded Warbler, Setophaga citrina, down by 85%. In S.E. Ohio, these are not rare warblers by any means, but at Ash Cave they are nearly nonexistent today.

                                Louisiana Waterthrush
Although I included a table at the end, the number of times we surveyed varied between the years, so comparing the total number of birds seen may be misleading. I think the best way to see the change is to average the number of birds per visit.

1980-81=16.7

2005-06=6.6

2013=4.7

Of the original 19 species from 1980-81, only 7 were recorded this past year.

                                Ovenbird
So what's happening? Succession of the old fields on either side of the picnic areas have made the habitat unsuitable for species like Prairie, Blue-winged, Yellow Warbler, etc. The hardwoods in the canopy can survive for several hundred years, and the Hemlocks easily twice that. So the vegetation through most of the park, including the understory, has remained the same over the years in regards to the plant species. It may simply be the forest structure has changed.

                                Yellow Warbler
Why does the understory still have Ovenbirds and Waterthrushes, but not Worm-eating Warblers? If they forage throughout the woods, their behavior should not have been affected. Has there been too much soil compaction from off trail hiking? Perhaps visitation in the park has reached numbers that are uncomfortable for this species to nest on the ground here. The same could be asked of the Hooded Warbler, which also prefers understory. Surveys often end up asking more questions than they answer.

                                Prothonotary Warbler
Other causes include the deforestation of tropical sites these birds overwinter in. The increased number of windmills, cell phone towers, and building collisions take their toll during migration. The change in land use in our country. Increased Cowbird parasitism is another factor. Pesticides, destruction of wetlands and riparian zones, climate change, and cats! (Don't get me started on that one). The list goes on and on. It's probably not one cause, but a combination of factors.

Locally, another threat looms on the horizon. The Hemlock Wooly Adelgid, Adelges tsugae, a piercing sucking insect that has wreaked havoc on the hemlock trees of the Smoky Mountains. Though not yet at Ash Cave, it has been found in the Hocking Hills region. The loss of Eastern Hemlock from the park would surely cause an even more rapid decline of species diversity.

                                American Redstart

Pat and I have written this up for publication.

All warbler photographs courtesy of Michael Williams.