Grand old American Elm

 

A massive American Elm (Ulmus americana), in post-dawn fog, yesterday. This tree is along State Route 104 in Pickaway County, Ohio. It is isolated from other trees in a cornfield; thus, the Dutch Elm Disease has not yet been able to find it. I rue the day it does. For years, I admired an even larger elm 15 miles to the south, but DED finally found it about a decade ago and quickly killed the behemoth.

While Dutch Elm Disease largely kills off elms before they achieve old-growth status (a very few seem to have natural resistance), the tree remains very common. Younger plants are plentiful in bottomland and other moist habitats, but DED invades most of them within a few decades. The days of grand old American Elms lining boulevards and forming sylvan pergolas over the street are long gone. But the young wild plants continue on with at least some of elms' long-evolved duties. Many of them still attain fruiting age, and their samaras are avidly consumed by a variety of songbirds. A large number of insects evolved specialized associations with elm bark, wood, and foliage, perhaps most notably some moth species such as Double-toothed Prominent (Nerice bidentata) and Elm Sphinx (Ceratomia amyntor).

One animal that has been largely shut out by the loss of ancient old elms is the Baltimore Oriole. The colorful blackbirds were quite fond of weaving their ornate nests into the lax outer branches of mature elms. They still do, if a specimen can be found. I would not be surprised if a pair of orioles is using the tree in my photo as a home site. It's a relatively short flight to other large trees across the road, and for the orioles it might be worth the travel to utilize an all too rare opportunity to use an ancestral nest tree.

PHOTO NOTE: I always look forward to driving by this tree on southbound commutes, and yesterday dawned mostly clear, but with thick fog in places, especially as I drove south. I figured there might be dramatic lighting and mist by the time that I reached the elm, which was a bit after 6:30 am (the early bird often gets the worm, in photography). Sure enough, light veils of mist enshrouded the tree, and the barely arisen sun cast interesting colors in the sky. I pulled off and clipped the Canon 70-200mm f/2.8 II to my R5 and set out on foot looking for angles. A 70-200mm lens is a staple for many photographers due to its useful versatility and I have had mine for many years now and use it a lot. Mostly for landscapes, and also botanical photography of a wide array of subjects. I'll often put a 25mm extension tube on to enable closer focusing and shoot all manner of small plants. No extension tube necessary for this elm, nor tripod. While I generally prefer prime lenses over zooms, in cases like this it is nice to have the ability to fine-tune the composition with just a twist of the wrist. This image is uncropped. Settings were f/8, ISO 200, 1/100, at 105mm, with in-lens image stabilization turned on.

Cardinal eating elm samaras, bonus bluebird

A Northern Cardinal (Cardinalis cardinalis) leans into some tasty American Elm (Ulmus americana) samaras. I was standing quietly near a woodland pond, watching the behavior of a pair of Wood Ducks, when I saw the red bird flit into the young elm. I figured he'd be after the fruit, and sure enough he was.

Trees undoubtedly evolved prodigious fruit production to counteract very high levels of predation by fruit-eating animals such as this cardinal. Even a young elm such as this produces far more seeds than could ever germinate and grow. And many samaras never even fall to the ground. They are plucked as soon as they ripen.

Caught in the act! An elm samara dangles from the cardinal's thick seed-crushing bill. He spent several minutes in the tree and wolfed down many elm fruits in that time. I'm sure many other birds regularly hit the tree and other elms in the area. I have seen a number of bird species harvest elm fruit over the years, but seldom get chances to photo-document them. I suspect it is because elms typically occur in dim haunts or thickety areas, the trees and their fruit are not overly conspicuous nor in biological hotspots likely to attract people such as myself, and thus I'm just not in the opportunity zone a lot.

As an aside, Dutch Elm Disease (Ophiostoma ulmi), a fungus which entered the Americas from Europe in the early 1900's, has ravaged American Elms. The stately tree once was used widely as an ornamental street tree. Today, DED has laid waste to the giants and big trees are increasingly hard to find. CLICK HERE for the tale of a giant Ohio elm that I long admired but finally met its demise a few years ago.

However, young American Elms remain abundant. Once they reach a certain size, the fungus invades and eventually kills them, but they are replaced by other young trees. It would be great if DED somehow hit a wall and eventually vanished, but there are no signs of that happening insofar as I am aware. But even saplings fruit heavily, thus they are an important natural food source for birds and various mammals.

Later that morning, this gorgeous Eastern Bluebird (Sialia sialis) landed nearby as I stood there, camera on tripod and ready to go. He and his mate had occupied a nest box not far off, and I think he came over to check out the interlopers. I find it nearly impossible to resist photographing bluebirds, especially when they present themselves as nicely as this bird did. His upperparts are cloaked in what may be the finest shade of blue, ever.

American Goldfinch, eating elm samaras

 

I got out for a few hours this morning to shoot birds, and visited a decent little local patch in Delaware County along the Scioto River. The American Goldfinches were conspicuous, and the males had mostly molted into their handsome yellow summer coats.

These males fairly bubbled over with song as they enthusiastically gamboled about, singing on the wing and from perches. I kept half an eye on them as I pursued various other quarry, and was pleased when this chap alit near the top of an American Elm sapling. In between bouts of song, he would pluck elm samaras (seeds) and crunch them down.

I quickly panned the camera to the goldfinch in the hopes of documenting not only one of our most beautiful birds, but to catch him in the act of samara-eating. And here he is, having just plucked one.

American Goldfinches are probably the closest thing to a feathered vegan in our neck of the woods. They will opportunistically take the occasional insect, but the overwhelming majority of their diet is vegetable matter. Even the nestlings are fed a regurgitated semi-glutinous gruel of partially digested plant matter.

Even though Brown-headed Cowbirds regularly parasitize goldfinch nests, the cowbirds chicks usually perish within three days. This near 100% mortality rate is apparently due to the lack of protein in the goldfinch's plant-based diet. Cowbird chicks, and those of nearly all of our songbirds, require ample protein in the form of insect-based diets.

Not so the interesting American Goldfinch, which bucks the dominant songbird dietary paradigm.

A tale of two elms

For many years, I would admire this massive American elm, Ulmus americana, on my trips to southern Ohio lands via State Route 104. It had the classic elm vase shape, and an enormous canopy spread. Then, about three years ago the tree began to show signs of being infected with Dutch elm disease. It succumbed quickly and its skeleton is rapidly disintegrating. I finally forced myself to stop and document its demise today. It sits near the southwest corner of the Ross County fairgrounds, not far north of Chillicothe.

Dutch elm disease is a virulent fungus that probably is indigenous to Asia. It somehow got to our shores in the early 20th century and quickly laid waste to our American elms. These stately trees used to be commonly used as street trees, forming overarching leafy canopies that shaded streets and such situations were apparently quite spectacular. Behemoths would have been quite common in wild landscapes as well.

Today, American elm is still very common, but generally only as saplings and small trees. Once they get to a certain size, the fungus attacks and takes them out. Gargantuan specimens such as the tree above are decidedly rare these days, and over the years I have watched many such isolated plants succumb to the Dutch elm disease.

Fortunately, about 15 miles up the road in Pickaway County is a survivor and I stopped to pay respects today. It, too, is isolated out in a field and the Dutch elm disease has not yet managed to get to it. I rue the day when I pass by and notice dead and dying branches - near certain signs that the fungus has gained a beachhead.

But maybe this amazing tree will be spared, who knows. It certainly looks grand now, and from what I can tell, healthy as a horse. Even though it's pretty far removed from other trees, I'd wager there are Baltimore orioles preparing to nest in it. Nearly every big elm like this that I've seen has its resident orioles. Back in the day, the colorful blackbirds were strongly tied to elms, and still are whenever they can find one.

Elms also host a massive assemblage of specialized moth larvae such as the amazing double-toothed prominent, Nerice bidentata. Its caterpillar specializes on elm foliage and the caterpillar's back is scalloped in such a way that it mirrors the serrations of the elm leaves.

Next time you're driving on State Route 104 in Pickaway County, watch for this behemoth on the east side of the road. It's 1.7 miles south of State Route 56. The tree even shows up readily on Google Earth!