Roads End Naturalist

Exploring the natural world as we wander at the end of the road

Night Lights

November 4, 2013
Glowing spots seen on the ground Saturday night (click photos to enlarge)

On Saturday night a couple of friends and I went on an impromptu night hike down the road to see what we might see (plus to help work off a large meal). It was fairly warm for early November but there was not a lot of activity other than a distant Barred Owl calling and the reflected light of what seemed like hundreds of spider eyes in the grass along the road. On the way back, I was ahead of the others and was inspecting some chewed leaves on a low branch when I noticed something on the ground. It was a slight glow in the grass.

Firefly larva

I turned my light on it and found a firefly larva, also called a glow worm. Since there are several other glowing creatures around the world commonly called glow worms, I prefer to call these lightning bug or firefly larvae.

Firefly larva top view

At first glance, they remind me of a short millipede without all the legs, or maybe a large sow bug. The dorsal segments look like overlapping plates that extend to the back and sides. Larvae emerge from eggs in late summer, and live through the winter before pupating in the spring. In some species, the larval stage lasts two years.

Light organs on underside of eighth abdominal segment of firefly larva

Firefly larvae in the family Lampyridae all have a light organ on their eighth abdominal segment which appears as two white spots. When they are crawling about, the light is diffuse and causes a soft glow on the ground. When you flip them over, the light looks like two tiny glowing eyes (the first photo shows two larvae on their backs). And in some species the eggs are also bioluminescent.

Light from the photic organ on the underside of a firefly larva

Adult fireflies use their flashing lights to attract mates. But the slow changing glow of the larvae must have another function. The light produced by the larvae is also a different color than that from adults – it tends to be shifted more to the green spectrum. Like the adults, larval fireflies contain some toxic compounds and are distasteful. Since the larvae are active primarily at night, it is believed that bioluminescence originated as a warning display, suggesting to predators that they are unpalatable. Research has also shown that the eyes of certain predators of larval fireflies are more sensitive to the green region of the light spectrum.

Firefly larva consuming snail

Firefly larvae live in the soil and leaf litter and crawl about at night hunting slugs, snails, earthworms, and other invertebrates. On a museum workshop in the Smokies several years ago, I came across a large firefly larva with its head inside a snail shell, presumably consuming the occupant. They apparently inject their prey with toxins that also serve as digestive enzymes, essentially liquefying the tissues.

Turns out that all of us on the hike had spotted the tiny night lights at about the same time. Walking back, we kept finding more of the faint glimmers in the grass. It was a great moment of shared wonder. As always, when you take the time to look around your surroundings, nature has a way of putting on an amazing show, including an eye-catching glow.

Firefly larva with head outstretched

We are all worms, but I do believe I am a glowworm.

Winston Churchill
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Mike Dunn
Macro Mystery #1 Answer

November 2, 2013
Macro Mystery (click photos to enlarge)

So, here is the answer to the Macro Mystery. It was found along the Inspiration Trail at Umstead State Park in Raleigh earlier this week. I was struck by the texture which reminded me of wavy golden hair or fur.

Mushroom

It was actually a close-up of the underside of a mushroom cap highlighting the wavy spore-bearing gills or lamellae. The mushroom was lying on the ground next to the trail. It was large, perhaps 5 inches across the cap. I am not sure which type it is, but based on the characteristics, it may be one of the Amanita species, many of which are poisonous if eaten. At the time, I wasn’t so interested in what it was as I was in the unusual pattern, so I did not turn over the cap to investigate. I am not sure if the wavy gills are diagnostic or whether they are an artifact of aging of the mushroom.

Mushroom gills with part of stipe (or stem)

NOTE: Someone pointed out that she was able to guess the answer because the name of the image showed up in the URL of the picture when clicked and enlarged. Oops…I’ll do better next time. And, sorry, there is no prize:)
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Macro Mysteries

November 1, 2013
I care to live only to entice people to look at nature. ~ John Muir

Macro Mystery #1 (click photo to enlarge)

Walking around with a macro lens helps me look at nature in a different way. Since even the smallest thing can have wonderful detail if only we stop to look at it, I have decided to share some of these small beauties in the form of an occasional post I will call – Macro Mysteries. The only criteria is that the photograph must be taken with one of my macro lenses, the Canon 100mm macro or the Canon MPE-65 macro. This one is from a woodland trail hike at Umstead State Park earlier this week. I will post the answer tomorrow.
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Hauntingly Beautiful

October 31, 2013
Tuesday afternoon I was joined by my good friend and mentor, Mary Ann, for a walk at Umstead State Park. It was a great chance to catch up and spend some time doing what we both love to do, woods watching. It was a walk back in time for me in a couple of ways – reminiscing about some of the good times we had at the museum helping people get excited about nature, especially the small things that surround us; and reconnecting with the place that started me on my path as a naturalist/educator. My first job as a naturalist was a summer seasonal job at Umstead in 1981 in between grants in graduate school. At the end of that summer, I had fallen in love with sharing the natural world with people, and, as luck would have it, a permanent position came open. I applied and was accepted as the East District Naturalist for the NC State Park System, and so my incredibly satisfying career began. On this day, we did what folks like us do, slowly walking and looking closely at everything from autumn leaves and tree bark textures to slight movements or patterns that catch a naturalist’s eye. The Inspiration Trail provided us with just that, and a seasonally-themed experience as well – a look at some hauntingly beautiful woodland spiders.

Tan Jumping Spider on Loblolly Pine trunk (click on photos to enlarge)

Our first spider was hiding in plain sight on the trunk of a large Loblolly Pine. It was a very fuzzy-looking jumping spider. Using The Spiders of the Carolinas field guide by L.L. Gaddy, I identified it as a Flat Jumper, Platycryptus undatus. A visit to the BugGuide.net web site revealed that it is more commonly known as the Tan Jumping Spider.

Tan Jumping Spider

This is a common species of jumping spider, which, like all of its cousins, builds no web, but instead relies on its’ keen eyesight and speed to capture prey. It favors vertical surfaces such as tree trunks, fences, walls, etc. It is easily observed as it tends to show no fear of humans, and may, in fact, be curious and jump onto a close hand or camera lens for a quick inspection. The bodies of these spiders are somewhat flattened in the vertical direction, which allows them to hide under loose tree bark and in other tight places. The prominent pattern on the dorsal surface of their abdomen is diagnostic of the species (the species name undatus refers to the undulating outline of the pattern). This coloration helps them blend in on mottled surfaces like bark.

Tan Jumping Spider close-up

A close look at this female shows the characteristic large pair of eyes in front and the dark single lashes above each of the other eyes. A male will have a reddish-orange stripe under the row of front eyes.

Magnolia Green Jumper on tree trunk

Next was a tiny specimen of one of my favorite jumping spiders, a Magnolia Green Jumper, Lyssomanes viridis. It is easily recognized by its two huge front eyes and the raised “eye mound” on top of the cephalothorax that is orange or yellow and contains the remaining eyes.

Young Nursery Web Spider

A little farther along the trail we came upon a young Nursery Web Spider, Pisaurina mira, posing on a leaf in its characteristic splayed-leg position. Females of this species lay an oval egg sac, pull some leaves over it, and secure the whole thing with some web. She then remains with the egg sac until the young spiderlings hatch and disperse in late autumn.

Marbled Orbweaver

The final spider of the hike was the most seasonally appropriate – a beautiful female Marbled Orbweaver, Araneus marmoreus. This large-bodied spider is abundant in autumn and, due to its timing and coloration, is often dubbed the Halloween Spider (it often turns more orange late in the season). Although the abdomen is usually bright yellow or orange, it does occur in many other color variations. This one was out in the middle of its web feeding on a small prey item, but I usually find them hiding in a curled leaf retreat off to the side of their circular web. It is always fun to suddenly reveal them to folks on a nature walk by reaching up and tapping the spider’s hideaway and have it come scurrying out. Now if I could only get them to line the pathway up to the door for Halloween night, I might be able to save some of my chocolate treats…
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Mike Dunn
Nice Doo

October 28, 2013
Banded Tussock Moth caterpillar (click photos to enlarge)

I usually think of the end of “caterpillar season” as being a week or two after the Museum’s annual BugFest event in September. This year (and maybe its just because I am retired and out and about more) I have been seeing the larvae of quite a few species in my travels well into October including Imperial Moths, Luna Moths, and the ubiquitous Woolly Bears. But around the house, there is one species that is dominant late in this season, the Banded Tussock Moth, Halysidota tessellaris.

Banded Tussock Moth larva on oak leaf

Full-grown caterpillars are about 1.5 inches long. Each body segment is densely covered with tubercles bearing tufts of short or long hairs (lashes) that are whitish, yellow-brown, silver-gray or black. From the second thoracic segment there is a pair of long black lashes and shorter white lashes that point forward, and from the third thoracic segment is a pair of black and white lashes that usually point away from the body at right angles. At the rear of the body, two black lashes point backward.

Banded Tussock Moth larva raising its body in search of a new perch

I am always struck by the tufts of “hairs” on certain caterpillars. They remind me of various things with texture – brushes (some are even like toothbrushes), some sort of elongate fancy breed of show dog, or a teenager with a wild hairdo.

Banded Tussock Moth larva crawling on white background

The true tussock moths, like the common White-marked Tussock Moth caterpillar, are members of a different family of moths, the Lymantriidae. The Banded Tussock Moth is a member of the Arctiidae, which includes the Tiger Moths.

Banded Tussock Moth caterpillar in a stare-down

This species is easily observed as it sits out in the open on leaves of its many host plants (oak, hickory, ash, and many other shrubs and trees) or in its travels to a pupation site. I am finding them now on my deck rail, the screen porch, the trash can lid, and just sitting or crawling on the ground. This boldness may indicate that they are distasteful or just too bristly for many birds. And one reference indicates that, like many members of the true tussock moth caterpillar group, the Banded Tussock may cause skin irritation in sensitive individuals. Guess I truly am an insensitive guy, as I have handled them with no ill effects.

Banded Tussock Moth larva in stationary posture
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First Frost

October 26, 2013
Frost-covered leaf (click photos to enlarge)

I looked out the window this morning and saw that the dawn had left its mark on the meadow – faint traces of ice coated the grasses and other low-lying vegetation under the power line – the season’s first frost.

Grass blade with ice crystals

Frost is deposition of water vapor directly into ice crystals on a cold surface. Frost typically forms on objects close to the ground, such as blades of grass. At night, a blade of grass loses energy by emitting radiation, but it absorbs energy emitted by surrounding objects. Under clear nighttime skies like we had last night, objects near the ground emit more radiation than they receive from the sky, and so a blade of grass cools due to the net energy loss. When temperatures hover near the freezing point and an object such as a blade of grass gets cold enough, frost will form on it.

Mourning Dove feather

Up on the hill above the garden, the frost had formed only on very low-lying objects – mainly the grass that I had recently mowed or objects lying on the grass such as a few feathers near the bird feeder station.

Sweet Gum leaf

As I walked downhill the frost had reached higher and by the time I reached the low point of the power line meadow, it had touched vegetation up to 2 feet off the ground (tree saplings, tall grasses, etc.) probably due to the sinking and collecting of cold, humid air in these low pockets overnight.

Frost Aster flowers

Even the aptly-named Frost Aster flowers had a coating of crystals at the base of the hill, but not up near the garden. As the sun rose higher, the icy filigree began its retreat until it finally lingered in only the deepest shade in the valley, and even there, it would soon succumb and have to wait for another dawn to be reborn. I welcome the first frost as a sign of good things to come – campfires under a starry sky, the simple pleasure of heating with wood that you cut and split yourself, and the return of migrants from the far north. It is just the beginning, but the cold, crisp nights of winter are not far behind, and with them, a new set of adventures. On the next chilly morning, go outside and look at the handiwork of frost and you will be amazed at her delicate attention to detail as she paints the landscape.

Horse Nettle leaf

Grass stems

Frost-lined leaf

Grass seed head

Purple leaf
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Elk and Islands in the Sky

October 22, 2013
Cataloochee Valley (click photos to enlarge)

I had an outing this weekend with a great group of folks in Cataloochee Valley and up on the Blue Ridge Parkway. Our goals were to observe the elk during the mating season ritual called the rut and experience the beauty of the mountains during the fall leaf season. I’d say mission accomplished on both. It was overcast and cool on Saturday morning as we drove into the valley. We were greeted at the entrance by one lone bull elk and a little farther down the road a large crowd of visitors at the first elk herd.

Bull Elk in Cataloochee Valley

One large bull was busy herding his harem of cows and occasionally chasing off a small spike bull that was feeding some distance from the herd of cows (but apparently not far enough away for the big bull). Early morning is one of the best times to see the elk as they tend to be feeding and, during the rut in September and October, interacting with one another.

Bull Elk bugling

Each year at this time males in their prime (usually 5 to 8 years of age) gather small herds of cows and calves and aggressively defend them from other bulls. This is done by a series of displays: bugling, a hauntingly beautiful and surprisingly high-pitched call; thrashing bushes and other vegetation with their antlers; and occasionally engaging in sparring matches with other large bulls by locking antlers and shoving in a show of strength.

Bull Elk courting a collared cow

When the cows come into estrus, the mating begins. A cow is receptive for mating less than 24 hours. She won’t be willing to mate again until her second estrus cycle arrives in 20 days so bulls are constantly checking on the cows in their herd. Bulls can be quite aggressive toward cows as they herd them, but then during courtship their behavior is decidedly more gentle. He may approach her and lick her to check her receptiveness and, if she is ready and willing, mount her to mate. This day had no actual mating or fights with other males, but the bull stayed busy, bugled often, and looked exhausted at times (bulls may lose 20% of their weight during the rut).

Palmer Church

The rest of the day we explored the woods and stream sides and walked around some of the many historic structures in the valley. Several houses and barns, a one room school, cemeteries and a church are all that remain of a once thriving community that had to leave when the land became part of Great Smoky Mountains National Park in 1934. There are auto tour brochures available for a nominal fee at the information kiosk near the valley entrance that give a detailed history of the valley and some of its notable inhabitants.

Bull Elk with fall color

Late in the day we found ourselves (along with hundreds of other visitors in often car-clogged roads) watching the elk as they returned to the fields after being in the shade of the forest much of the day.

Early morning mist along Blue Ridge Parkway

The next morning most of the group wanted to head up onto the Blue Ridge Parkway for some fall color so we headed out and started heading north from Balsam Gap. The cool night and humid atmosphere had created ideal conditions for mist and low hanging clouds, a photographers dream for this time of year on the Parkway.

Ocean of clouds in valley below Blue Ridge Parkway

At first, we saw only patches of mist hugging some ridges. As we climbed in elevation and the road shifted to the other side of the mountains, an ocean of clouds spread out above the valley floor with isolated peaks popping through the gray sea. This type of scene has given rise to the name, Islands in the Sky, for these mountaintops protruding above the misty sea of clouds. It also refers to the unique ecological communities that are adapted to the cold conditions atop our highest mountains.

Panorama from Richland Balsam

As we continued north, the warmth of the sun caused the sea of clouds to recede leaving us with an unobstructed view of row upon row of ridges speckled with fall colors.

Lower part of Yellowstone Falls

Our final stop was a short hike down to Yellowstone Falls, one of the more popular hikes along this section of the Parkway. After winding through a thicket of Rhododendron and Mountain Laurel, you come out on a beautiful series of waterfalls. The hike is well worth the steep climb back out. And here’s something to consider next time you visit a popular waterfall. If you are at the top of the falls and look down and see a group of people with cameras looking up at you, try not to stay too long out in the open…they may be waiting for a chance to get a photo or two of the scene without people in the picture. As we parted ways, I think we all were appreciative of the sights and sounds we had experienced on this magnificent fall weekend. I look forward to the cooler weather and changing landscape and wildlife that the new season will bring.

Here are a few more photos from the trip.

Boards of historic barn in Cataloochee Valley

Young bull Elk with velvet on antlers

Rough sawn board on Palmer barn

Mountain Ash berries

Sassafras leaves

Red Spruce against ocean of clouds
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A CROWDers Pleaser

October 16, 2013
Stone Mountain State Park (click photos to enlarge)

The past several days II have been on the road in the mountains of North Carolina. I had a program on Saturday at Stone Mountain State Park and had a great hike across the large granite dome for which the park is named. The park was packed with campers and hikers taking advantage of the start of fall colors and perhaps visiting an open state park instead of the many federal lands closed by the unfortunate government shutdown.

Crowders Mountain State Park

After a rainy couple of days along the Blue Ridge Parkway (the road is still open but facilities are closed) I visited Crowders Mountain State Park near Gastonia. The weather cleared and the two mile hike to the summit of The Pinnacle was a welcome sunny stroll.

Chestnut Oak forest

The main trail passes through a forest dominated by Chestnut Oak, Virginia Pine, and Sourwood, with an open understory of Sparkleberry, Sassafras, Dogwood, and various herbaceous species adapted to the dry rocky slopes.

Phengodid Beetle female or immature

There was a lot of frass (caterpillar poop) on the trail and a couple of the frass-makers were spotted along the way, including a huge Imperial Moth larvae and a Luna Moth caterpillar on Sourwood (yes, I really do look for such things while hiking). But one thing on the trail really stood out – an unusual larviform creature about 2 inches long. I recognized it as an amazing beetle I had once found on a night walk at another state park in the Sandhills. On that night, I saw a bright glow on the trail and stooped to pick it up. It looked like a worm or caterpillar with a series of bright glowing dots on each side. It was so bright I could read my watch by it. I have since found several of these so-called Glowworms (not to be confused with some Lightning Bug larvae which are also known as Glowworms). This one is the larva or adult female of a Glowworm Beetle, probably in the genus Phengodes. The females and larvae are bioluminescent. The pattern of glowing dots is said to resemble a train car illuminated from inside at night and has given this unusual insect another common name – Railroad Worm. Adult females are wingless and almost indistinguishable from the larvae. Both are predaceous on millipedes, which they resemble in color and shape. Adult males have wings, probably do not feed, are active primarily at night, and are adorned with intricate antennae. See http://bugguide.net/node/view/9382/bgimage?from=0 for more photos of these bizarre insects.
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Dolly Sods

October 10, 2013
The mountains are calling and I must go.
John Muir

For my birthday a couple of weeks ago, I decided to revisit one of the most beautiful places I have been in the East, Dolly Sods Wilderness in West Virginia. Many years ago I had read about this unique highlands area and had wanted to visit ever since. Last year I finally made it and it was worth the wait.

Dolly Sods is a 17,000+ acre wilderness in the Monongahela National Forest in West Virginia. It is an unusual environment in that it contains bog and heath bald habitats which are much more typical of southern Canada.

Dominant trees include Red Spruce, Sugar Maple, and Quaking Aspen. On some trails I feel like I am walking in Yellowstone, Alaska, or Canada.

There are miles of well marked and easy to hike trails. They take you through a variety of habitats as you pass from open bald into forest. To me, one of the more amazing things about this beautiful place is the abundance of ferns. Hay-scented and Bracken Ferns seem to dominate, and they occur in huge patches in the balds and the forest understory.

Fall color was at its peak when I was there, and the highlands of Dolly Sods are absolutely incredible with a variety of colors from blazing red to bright yellow both on the ground and in the trees. Last year I was there a week later and had to leave a day early because it started snowing. This area is known for harsh weather conditions, so visitors need to be aware of changing conditions and come prepared.

The area is rich in fruiting shrubs and groundcover including many species of blueberries, huckleberries, and cranberries. The tart cranberries made a delicious addition to breakfast oatmeal.

The area reportedly has some unusual wildlife such as Fisher and Snowshoe Hare, again, much more like northern forests than other areas of the Appalachian Mountains. I did see some evidence of Black Bears this time and heard the howls of Coyotes and hoots of Barred Owls late at night.

Throughout the trail system there are a number of well established campsites. The area is pretty heavily used so I recommend camping in these locations so as not to create more disturbance to this unique environment. Since I was backpacking I did not carry my usual assortment of camera gear but relied on my phones’ camera instead. I leave you with a few images of this beautiful area that I will surely visit again.
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Extreme Dining

October 6, 2013
The abundance of insects feeding on pollen and nectar in the goldenrod patch out on the power line has naturally attracted an array of predators.

Wheel Bug (click on photos to enlarge)

One of the more formidable-looking of these is the Wheel Bug, Arilus cristatus, our largest member of the so-called Assassin Bug group. Wheel Bugs are named for the unusual gear-like projection on the dorsal surface of the thorax of the adult insects. They are efficient predators of many types of insects including caterpillars, beetles, and bees. Wheel Bugs move slowly through vegetation like goldenrod searching for prey which they grab with their long front legs and then pierce with their stout beak. Their saliva contains a toxin that immobilizes and kills its victims within a minute or less. They then drain the body fluids from the victim. That same beak can inflict a painful bite on a human if you accidentally grab a Wheel Bug, but, left to their own, they will not bother us. In fact, Wheel Bugs are considered beneficial garden insects as they prey on a number of bugs we consider pests.

Wheel Bug and Honeybee prey

I encountered a couple of these impressive insects while walking through the goldenrod last week. One was hunting on some flowers, the other had successfully captured a Honeybee. I grabbed a few quick photos and moved on. When I looked at the images later I noticed something I had missed in the field.

Wheel Bug with bee with Freeloader Fly

There was a tiny fly on the bee near the point where the Wheel Bug was feeding. I recognized it as one of an interesting group of flies known as Freeloader Flies. These tiny marauders are kleptoparasites and steal a meal from the jaws of predators such as Assassin Bugs and various spiders. I had seen them once before in the garden when I photographed a Black and Yellow Argiope Spider feeding on a Stink Bug.

Black and Yellow Argiope with prey

On that day, I once again did not see the tiny flies until I had taken a few images. At that time I had no idea what these miniature thieves were and was not even sure what they were doing other than living dangerously. A web search helped me discover the amazing world of kleptoparasitic flies.

Freeloader Fly stealing a meal at the jaws of an Argiope Spider

Other names for this interesting group of insects include Jackal Flies and Filth Flies (their larvae feed on decaying organic matter and some species may develop in manure). They apparently are attracted to their meal by chemical odors released by the victims. And it is unclear whether they are merely licking spilled fluids from the victim or whether they may actually penetrate the cuticle of the prey and ingest tissues that the predator has liquified by its injections into the dead prey. The adults of some species of Freeloader Flies have been observed to follow a particular predator in order to partake of its meals. I guess in this case, it is a different sort of meals on wheels:)
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