Wednesday, June 22, 2016

Teeming with rabbits

The golden glow of a June sunset in Muskingum County, Ohio illuminates an adult Eastern Cottontail. This is one of the most abundant Leporids (rabbits) in the Americas, ranging throughout the eastern U.S. and south all the way to northern South America. It was even (quite stupidly) introduced throughout the Caribbean and even in Italy. But probably nowhere are they as plentiful as right here in the heartland of Ohio and the Midwestern U.S.

Life is fraught with peril for bunnies. They are basically saltatorial steaks, and many predators avidly seek them. Here, a kit not long out of the nest secretes itself in dense cover along an open grassy area filled with succulent rabbit fare. This youngster must quickly learn the survival ropes; the mortality rate for cottontails is very high.

For whatever reason, the cottontail population seems to be flourishing this year. On last weekend's trip to Muskingum County, I must have seen nearly two dozen, mostly kits. I've also seen lots elsewhere, and have heard others comment on the abundance of rabbits in other areas of Ohio.

Our secretive little rabbit eventually worked up its courage to enter the open grassy expanse and snack on dandelion leaves. At one point, another kit rabbit joined it and they engaged in a bit of frisky sparring. Who knows, it may have been a prenuptial courtship display - some cottontails mate and produce young in their first summer. Since the average lifespan for one of these rabbits isn't much over a year, no sense in wasting time.

Eastern Cottontails, cute as they are, are an essential ingredient in the predatorial web. They are important fare for foxes, coyotes, bobcats, and larger owls, especially the Great Horned Owl. I would imagine all of these carnivores are enjoying lots of rabbit steak this summer. And that's a good thing, lest we be overrun with rabbits. Female cottontails, on average, have three or four litters a year, each of about five kits. That's 15-20 rabbits spawned per female in a year. Somewhere between 10-25% of those new does will raise their own litters within two or three months - most wait until the following spring. Take all of the predators out of the equation, and say a 15-acre piece of rabbit heaven supported 20 sexually mature does. Each raises 15 kits in a year (some especially fertile females can produce 35 annually!) - 300 new rabbits. Say 15 of those 300 are females that breed in their first summer, and they collectively spawn another 75 kits. In short order the bunny Eden is overrun with 375 new rabbits. And these numbers are probably conservative.

I'll repeat, good thing for predators.


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Sunday, June 19, 2016

Wasp puts on reproductive show in Hocking County preserve

A Xorides stigmapterus wasp lays eggs in a maple.

Wasp puts on reproductive show in Hocking County preserve

NATURE

Jim McCormac
June 19, 2016

On May 12, I trekked into a wild area of Hocking County along with top-notch biologists Dave and Laura Hughes, and Joe Moosbrugger. We found scads of interesting flora and fauna.

Trumping all was a 1-inch wasp. As we navigated a steep slope, someone noticed an ornately marked wasp on the bark of a dying sugar maple. Its most distinctive feature was an incredibly long ovipositor.

We had found one of the giant Ichneumon wasps and settled in for a ringside seat to part of its amazing reproductive cycle.

The female wasp somehow divines the location of beetle grubs feeding deep in the wood of trees. She then unfurls an ovipositor that might exceed her body length. The wasp slowly bores deep into the wood until her ovipositor makes contact with the victim.

Once she reaches the grub, she squirts a semi-solid egg down her ovipositor and onto the grub. The egg soon hatches and the wasp larva chews into its host and begins eating it alive. It ultimately kills the beetle grub, then forms a cocoon and metamorphoses into an adult wasp. Other Ichneumon wasp species prey on caterpillars, spiders, flies and others.

It took 15 minutes for the wasp to complete her wood-drilling operation. Ichneumon wasps are vulnerable during the process; many are snapped up by birds or other predators as they are lodged in the wood.

Entomologist Ross Hill identified the wasp as Xorides stigmapterus. Naming most Ichneumon wasps is not easy. About 24,000 species have been named to date worldwide. There may be two or three times that many yet to be described. At least 3,300 species have been found north of Mexico.

Xorides stigmapterus preys on wood-boring grubs of the six-banded longhorn beetle. This large beetle is thought to be rare. I’ve seen only one, and it was sensational: bold yellow with tigerlike black bands, and enormous recurved antennae.

Six-banded longhorn beetles are associated with old-growth timber and feed within large sugar maples — the tree species our wasp was on. Thus, it is likely that the wasp also favors climax stage woodlands, mature woodlands dominated by fully grown trees. Such forests are rare and worthy of protection, as they are major contributors to biodiversity.

Fortunately, the site where we observed this wasp — and myriad other critters — is protected as a private nature preserve.

Charles Darwin, upon learning of the horrific (to us) reproductive strategies of Ichneumon wasps, wrote to the American botanist Asa Gray: “I own that I cannot see as plainly as others do, and as I should wish to do, evidence of design and beneficence on all sides of us … I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars, or that a cat should play with mice.”

Amen.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.

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Thursday, June 16, 2016

Beech tree killer still unknown, UPDATE

A forest of young American beech, Fagus grandifolia, withering under the attack of an as-yet unknown plant disease. Lake County, Ohio.

Just over two years ago, I wrote about a mysterious affliction that was decimating American beech trees in parts of northeastern Ohio. You can read that post RIGHT HERE. It was brought to my attention by John Pogacnik, biologist with Lake County Metroparks.

Last week, John reported with an update, and the news is not good. Experts remain stymied as to the cause of the affliction, which seems to be spreading. All of the photos, and much of the text (lightly edited) that follows, is from John. Read on, and then see recent photos of affected trees following the text. All photos, I believe, were taken recently in Lake County, Ohio.

"Basically experts have been looking at it for three years now and cannot nail down a cause.  They have studied the roots, leaves, buds, and branches, but cannot find anything.  They see problems, but they appear to be there because the trees are dying or stressed and are not the cause.  Holden Arboretum has a project where they are carefully studying affected trees to document how the disease is spreading.  The Ohio Division of Forestry and US Forest Service will use this information and what I have compiled to apply for a grant to hire a grad student to study it full time.  I think that may be the way to go. 

We have parks like Hell Hollow where 100% of the beech are affected.  I am seeing some prime breeding bird habitat changing drastically.  What once were dense shady stands of beech and hemlock are now becoming open and sunny.  I am seeing a decline in some of the hemlock nesting species already.  Hell Hollow has thousands of beech and I cannot find any that are not affected.  To give you an idea on how fast it spreads, at Chapin Forest I found three affected trees in 2014.  In 2015 about 25% of the trees showed signs of the disease.  This year at least 70% of the trees are affected and some are really looking bad.

It appears that the disease shows up first as a few striped leaves.  It might be just on the tip of a single branch.  My guess is that in the winter it goes down into the roots and the following year all the trees in the clone are affected.  In smaller trees later stages of the disease will have only a few leaves that are at the tips of the branches and these leaves are curled up and contorted.  There are typically unopened buds on the branches.  The trees typically do not drop the leaves until fall or winter.  The leaves come out of the buds all contorted.  They look dead upon opening in May.  The leaves and trees do not get worse later in the year.  Large trees appear to be dying from the bottom up.

 It appears it originated from somewhere in the south end of the central part of Lake County.  Spread has been very rapid to the east and slowly to the west.  This tells me it is probably wind driven.  What scares me is unlike with the ash borer that leaves some trees untouched, this affects every tree.

Things to look at identifying the disease are the striped leaves.  They are best seen looking up into the crown.  Anthracnose can look somewhat similar, but lacks the striping.  The leaves also remain on the branches through summer.  They do not drop and get replaced by new leaves as in anthracnose.

I’ve attached shots showing the upper and lower surfaces of the striped leaves, latter stages of the disease, and what some of the affected areas look like.

Unfortunately for us, this is just the tip of the iceberg.  We also have emerald ash borer going through.  We also have something killing sassafras.  This might be from an Asian ambrosia beetle.  We have elongate hemlock scale at Chapin Forest and Penitentiary Glen that will end up killing hemlocks.  This is the first “wild” occurrence in Ohio. 

I am also seeing large areas of dying trees that may be a result of Armillaria fungus.  At Penitentiary Glen there is an area almost 5 acres in size that is spreading outward.  These areas are kind of interesting though.  They occur in wet areas where there are seeps.  The open sunlight and rich soil increases plant growth causing a lush growth of grasses, sedges, and forbs.  The open light attracts things like red damsels, spiketails, and wetland butterflies.  Some of the oaks that are dying are 100-150 years ago.  There some amazing ecological changes going on here.  I think the extremes in weather due to climate change are stressing out the trees making them more susceptible.  Add to that the earthworms which are rapidly also getting worse and you have a an ecological disaster."

Affected newly emerged leaves

Heavily affected leaves

Underside of leaf

Upperside of leaf

Heavily affected young American beech grove

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Tuesday, June 14, 2016

A dangerous flower-stalker

The Amen of Nature is always a flower.
--Oliver Wendell Holmes

The ivory flowers of White Milkweed, Asclepias variegata, are irresistible to pollinating insects. And photographers.

I had a great day last Sunday down in Shawnee State Forest, birding with Carl and Karen Winstead. We found many species of birds, with good looks at choice feathered bits such as Cerulean, Kentucky, and Worm-eating warblers. Lots of plants, butterflies, dragonflies and other elements of natural history, too.

After the Winsteads and I parted ways in late afternoon, I took the long way out of the forest, stopping to shoot some interesting subjects, mostly plants and insects. And is often the case when loitering around insect-rich plant life, I was witness to a kill by a spectacular flower-stalking insect that hunts other insects.

A Silver-spotted Skipper, Epargyreus clarus, taps nectar from the small blossoms of Spiked Lobelia, Lobelia spicata. These large, easily identified skippers are quite common in Shawnee, and are especially smitten with the flowers of American Ipecac, Porteranthus stipulatus, which forms large drifts of flowers along favored road banks.

Another plant that is at peak flower right now is the New Jersey Tea, Ceanothus americanus.  This small shrublet often forms rather sizable colonies, and if it is interesting insect activity that you seek, hanging out around the New Jersey Tea is sure to result in some action.

The Lilliputian white flowers of New Jersey Tea are typically awash in small pollinators: beetles, flies, wasps, and native bees such as the one in this photo.

A platoon of Summer Azures, Celastrina neglecta, works over a lump of coyote scat, tapping minerals.  While fresh scat draws many butterflies, they also seek out flowers and the New Jersey Tea is a favorite for some of the smaller species, including this one.

A Summer Azure on a more photogenic backdrop than coyote scat, the flowers of Dogbane, Apocynum cannabinum.

I spent a fair bit of time observing some especially large New Jersey Tea colonies, attempting to photograph visiting pollinators. Many Summer Azures were regular visitors to the flowers.

At one point, an odd rather large shape whirred by, looking like it was trailing a small blue flag. Fortunately the unidentified flying object did not go far before settling onto a leaf. A robberfly! With a freshly captured Summer Azure! I crept in and managed a nice series of images of the spectacle.

It turns out that this species of robberfly is Asilus sericeus (thanks to Benjamin Coulter for the ID), and it is well known for attacking butterflies. One source states that it is not particularly common, and my experiences would bear that out. I tend to notice such things as large spectacular robberflies, and don't recall seeing Asilus sericeus before. As robberflies go, it is quite handsome with its rich golden tones.

Once again, the reality of flowers as potential death traps is reinforced. Robberflies and myriad other predators often lurk near flowers that support heavy pollinating insect activity, and routinely make a meal of the flower visitors. Brutal as this may be, it's all part of the circle of life.

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Thursday, June 9, 2016

Wild Lupines

Colorful clumps of Wild Lupine, Lupinus perennis, dot a recently burned oak savanna at The Nature Conservancy's Kitty Todd Preserve in the Oak Openings west of Toledo. This well-managed tract is one of the best places to get a flavor for one of the Midwest's most unusual habitats, and its rare denizens. I was there back on May 14, and made these photos during that foray.

Bright blue jolts of lupine flowers enliven a sand blowout at Toledo Metroparks' massive Oak Openings Metropark. Lupine, at least this species, grows best in dry sandy substrates. The Oak Openings has plenty of sand. This elliptically shaped region encompasses the old beaches and dunes of pre-glacial Lake Erie, dating from a time when the lake sprawled much further inland than it currently does.

Lupine is a rarity in Ohio, and nearly all populations occur within the Oak Openings. Hit the right spot, and there can be a lotta lupine, creating spectacular blue clumps and besting any ornamental plant in the looks department. If you are a seeker of rare flora, there will be plenty of other goodies to find. The Oak Openings and its unusual habitats harbor probably the greatest number of rare plant species of any place in Ohio, of similar size.

Even lupine leaves look good, artsy propellers on petioles.

Emerging lupine inflorescences, as soon from above. Another great thing about lupine-watching is that they bloom at arguably the best time to be outdoors in Ohio - mid-May. Birds are singing all around, interesting insects are active, and myriad other flowering plants are doing their thing.

Lupine flowers begin as thick spikes of tightly appressed buds . The flowers begin opening at the base of the spike, and gradually open upwards until a gorgeous open wand is formed.

A perfect trio of lupine flower spikes, nested in a sea of showy leaves. A photographer's dream.

One of the clumps at Kitty Todd was adorned with these unnaturally pale flower variants, which stood out from afar.

Should chance permit, I'd highly recommend a visit to the Oak Openings next May. The aforementioned Kitty Todd Preserve and Oak Openings Metropark are must-see destinations. Take a camera.

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Tuesday, June 7, 2016

The amazing Canon 5DS-R

The amazing new Canon 5DS-R, which was released about one year ago. I had been paying close attention to this camera, as my trusty 5D Mark III was going on three years old, and had lived a hard life. It was getting near time to replace it, and I was seeing stunning results that some nature and wildlife photographers were getting with the 5DS-R, most notably Artie Morris. So, last April I rented one and took it with me to Kansas to shoot prairie-chickens. That's all it took. I was sold and traded in the old workhorse 5D Mark III (120,000 shutter actuations), and got my own 5DS-R almost immediately after returning from that trip.

I've lived with this camera for nearly two months now, and love it. Probably the most noteworthy thing about the camera is its enormous resolution: a whopping 50 megapixels! At first, I thought this might be hype, an arms race of oneupsmanship with Nikon, to best their 36 megapixel D800. I've come to the conclusion that enormous megapixelism isn't just hype - it allows for a level of editing previously not available with DSLR cameras. There are downsides, but not many. One is the massive file sizes. A jpeg can run to 15 megabytes, while a RAW file might be 60-70 megabytes. This means your storage systems may soon be taxed, but that's really not a big deal - hard drives have gotten much better, bigger, and cheaper. Your computer also has to be up to the task of dealing with very large files.

The 5DS-R doesn't have quite the burst rate I'd hope for. It's about 4 or 5 frames a second - half that of the Canon 7D II, and about a third the rate of the new 1DX Mark II. But that's really only important when shooting birds, or perhaps a few other types of fast-moving wildlife. And 4 or 5 rounds a second still generally works well, even for birds. The focus acquisition is stellar, too. If the light is fine, I'll still often use the 7D II for bird photography, but the 5DS-R has supplanted it for nearly everything else, increasingly including birds. Unfortunately, it does not handle high ISO ranges very well, which is a handicap, but again, that generally only comes into play (for me) when shooting birds.

Here's a few 5DS-R examples from the past week.

NOTE: The following images are minimally edited JPEGS. Had I used the RAW files, and spent more tweakage time, which I don't have at the moment, the final product would look even better.

Four-spotted Skimmer, Libellula quadrimaculata, Wilderness State Park, Michigan. Uncropped.

Same photo as above, tight crop. As always, click the photo to enlarge.

Summer Azures, Celastrina neglecta, on coyote scat, Shawnee State Forest, Ohio. Uncropped.

 Same photo as above, tight crop. As always, click the photo to enlarge.

Red Clover, Trifolium pratense, Scioto County, Ohio. Uncropped.

Same photo as above, tight crop. As always, click the photo to enlarge.

Mourning Warbler, Geothlypis philadelphia, Pigeon River State Forest, Michigan. Uncropped.

Same photo as above, tight crop. As always, click the photo to enlarge.

You can see the camera's unease with higher ISO ranges beginning to manifest in the warbler shot. I let the ISO get a bit high - 1000. It's best to try and keep the ISO to 800 or lower, but had I been closer to the warbler and not cropped so heavily, this would not really be a problem. And if the crop were not so extreme, ISO noise would not be nearly so obvious.

If you're in the market for an excellent DSLR camera, I'd highly recommend the Canon 5DS-R.



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Monday, June 6, 2016

A positive note about flies

In my warm-season wanderings, I notice flies. Lots of flies, everywhere, in all sizes, shapes, and forms. Mostly doing interesting things, and more often than not, very valuable things.

Flies get a bad rap. Ask your average person what comes to mind when "fly" is mentioned, and it'll usually be some variation of "yuck". What a huge injustice to the massive order Diptera, which is estimated to include one million species. It is only a tiny thimbleful of fly species that cause the all-important Homo sapiens issues - the overwhelming majority are beautiful insects that play essential roles in ecosystems, and mostly go unnoticed.

As I've been working through photo edits from recent excursions, I came across a few fly photos that show a trio of examples of fly coolness and value.

One of the most beautiful wildflowers of the North Country is Bird's-eye Primrose, Primula mistassinica. It grows in profusion on cold, gravelly shores of lakes Huron and Michigan at the northern tip of Michigan's Lower Peninsula, where I've been going annually for the past seven years.

The flowers of this diminutive species are irresistible photo subjects, and when I came across a drift of especially colorful specimens in Wilderness State Park last week, I naturally started in with the camera. It wasn't long before I noticed this tiny flowerfly in the family Syrphidae plunging into the pollen-laden depths of the flowers. A great many of our wildflowers depend upon insects to move pollen from plant to plant, and scores of species of flies play a major role in pollination.

Here's proof of fly pollination. This species, which resembles the common housefly but is decidedly not (although I do not know the species), is caught red-handed (or eyed) as it services another native wildflower, the Starry False Solomon's-seal, Maianthemum stellatum. This photo was made shortly after the one above it. The fly appears to be eating pollen from the anthers. Some of that pollen will adhere to the fly's body, and eventually be rubbed across the whitish bottle-shaped process in in the flower's center, which is capped by the stigma. Thus pollinating the plant. This fly and others of its ilk methodically brushed their way through many of these flowers, and certainly they play some role in the lily's pollination.

I made this image last Saturday in Shawnee State Forest in southern Ohio, and it shows the toughness of our big predatory robberflies. I was kneeling on a dry embankment along a remote forest road, photographing a very cool plant known as goat's-rue, Tephrosia virginiana. Suddenly I heard the buzz of loud wings, and this pair of medium-sized robberflies (about an inch long) comes roaring in, mating on the wing (I'm unsure of the species). They ran headlong into the web of an orchard spider, and seemingly became ensnared. In this photo, the pair hangs suspended from the silken strands, but apparently still quite intent on their amorous coupling.

The spider, which was hanging in the web, made no move to approach the ferocious predatory flies. Finally, I moved in a bit too close, the flies stirred from their trance and easily broke free of the web, flying to a nearby leaf to continue on. Even a venomous arachnid caused no worries for the six-legged beasts. Woe to any creature their size or smaller than crosses paths with one of these flies when it's hungry. Or perhaps interrupts them in flagrante delicto.

Robberflies are the Peregrine Falcons of the fly world.

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