April 29, 2012

CATTLE EGRETS AMONG CATTLE
As in Mexico, around here if you pass by a pasture you're likely to see Cattle Egrets standing among or on the cows, as shown at https://www.backyardnature.net/n/12/120429eg.jpg.

Cattle Egrets in their breeding plumage, like the ones in the picture, can be distinguished from other white egrets and herons by the patches of light orange-brown on their crests and chests. Nonbreeding Cattle Egrets can be all white, and then their relatively thick, yellow beaks and thicker, shorter necks separate them from similar-sized, white herons and egrets found here, such as Snowy Egrets and juvenile Little Blue Herons.

I remember the first time Cattle Egrets were spotted in the rural part of western Kentucky where I grew up, possibly in 1963. Their appearance was so unusual that a farmer not particularly interested in Nature called my parents and said that a whole flock of big white birds had appeared in his pasture, and we went up to take a look. I was in college before I learned that they were Cattle Egrets, BUBULCUS IBIS.

My ornithology teacher told how the birds were undergoing one of the fastest and most widely ranging expansions of distribution ever seen among birds. Originally Cattle Egrets were native to southern Spain and Portugal, tropical and subtropical Africa and humid tropical and subtropical Asia. In the late 1800s they began expanding their range into southern Africa, and were first sighted in the Americas, on the boundary of Guiana and Suriname, in 1877, apparently having flown across the Atlantic Ocean. They didn't get permanently established there until the 1930s, though, but then they began expanding into much of the rest of the Americas, reaching western Kentucky around the early 60s. The species appears still to be expanding northward in western North America, but in the Northeast it seems to be in decline. Though they can turn up as far north as southern Canada, coast to coast, mostly they breed in the US Southeast.

The Wikipedia expert says that Cattle Egrets eat ticks and flies from cattle. They do that, but anyone who watches our birds awhile sees that mainly as the cattle move around they stir up creatures in the grass, which the egrets prey on. The cows' fresh manure also attracts flies for them.

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MATING BOX TURTLES
Hillary on the Mississippi Gulf Coast sent us a picture of two Box Turtles, TERRAPENE CAROLINA, mating in his backyard, shown at https://www.backyardnature.net/n/12/120429tu.jpg.

It's interesting to see how turtles manage it, but for many readers familiar with box turtles in other parts of North America the picture may raise the question of why those in our picture bear different colors and patterns than theirs. What's happening is that Box Turtles are represented by six intergrading subspecies.

Hillary's Gulf Coast location is supposed to be home to the Gulf Coast subspecies, Terrapene carolina ssp. major. However, that subspecies is described as having a brownish top shell, or carapace, sometimes with a few dull spots or rays, but nothing like these bright, yellow lines. I can't say what's going on. Apparently Box Turtle taxonomy is a bit tricky.

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RESTING CRANE FLY
Resting on a White Oak leaf in deep shadow below other leaves, a crane fly sat still long enough to grant the image at https://www.backyardnature.net/n/12/120429cf.jpg.

That looks like a mosquito but you can see from how much of the leaf he covers that he's far too large to be any mosquito species found here. Also, he lacks the hypodermic-like proboscis mosquitoes use to suck blood. No conspicuous mouthparts are visible on our crane fly because adult crane flies generally hardly eat at all, only occasionally lapping up a bit of pollen or sugar-rich flower nectar. Their maggot-like larvae feed on plant roots. Some species can damage crops.

Oosterbroek's monumental, 2012 Catalogue of the Craneflies of the World -- free and online at http://ip30.eti.uva.nl/ccw/ --recognizes 15,345 cranefly species, 1630 of them just in our Nearctic ecozone, which embraces the US, Canada, Greenland, and most of northern Mexico.

That's why when I shipped the picture to volunteer identifier Bea in Ontario it took more time than usual for her verdict to come in, and she was comfortable only with calling it the genus TIPULA.

Whatever our species, it's a pleasure to take the close shown at https://www.backyardnature.net/n/12/120429cg.jpg.

What are those things below the wings looking like needles with droplets of water at their ends? Those are "halteres," which commonly occur among the Fly Order of Insects, the Diptera. Though their purpose isn't known with certainty, it's assumed that they help control flight, enabling flies to make sudden mid-air changes in direction. From the evolutionary perspective, halteres are modified back wings. Most insects have two pairs, or four, wings, but not the Diptera, as the name implies -- di-ptera, as they say "two-wings" in classical Greek.

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ADMIRING THE WHITE OAK
For me nothing is prettier than a tree, and one of the most graceful and good-to-look-at trees is the White Oak of eastern North America, QUERCUS ALBA. If I had to pick a "representative tree leaf," I'd pick White Oak leaves such as those shown at https://www.backyardnature.net/n/12/120429qa.jpg.

In that picture I'm holding a leaf so you can see its underside, much paler than other leaves' topsides. The tree's gray bark of narrow, vertical blocks of scaly plates is shown at https://www.backyardnature.net/n/12/120429qc.jpg.

I'm accustomed to seeing White Oaks on relatively dry upland soils so I was a little surprised when the tree in the picture showed up on a stream bank growing among Sycamores. In fact, White Oaks are fairly rare around here, completely absent in many upland forests where I'd expect them to be. Years ago I mentioned this in a Newsletter and a local reader responded that in this region White Oaks were wiped out many years ago by people cutting them as lumber and, more importantly, using them in the whisky distilling business. The online Flora of North America says that "In the past Quercus alba was considered to be the source of the finest and most durable oak lumber in America for furniture and shipbuilding."

There beside the stream, last year's crop of our White Oak's acorns had been washed away, but this season's were there in their first stages of growth, as seen at https://www.backyardnature.net/n/12/120429qb.jpg.

Traditionally early North Americans regarded the inner bark of White Oaks as highly medicinal. Extracts made from soaking the inner bark in water are astringent (puckery) and were used for gargling, and the old herbals describe the extract as tonic, stimulating and antiseptic. Other listed uses include for "putrid sore throat," diphtheria, hemorrhages, spongy or bleeding gums, and hemorrhoids. Many applications suggest adding a bit of capsicum, or hot pepper, to the extract.

Basically the notion seems to be that the bark's tannin -- the puckery element -- does the main medicinal service. Other oaks actually have more tannin than White Oak, but medicines made with them can be too harsh. White Oak extracts seem to have just the right amount.

The same tannin situation exists with regard to the edibility of acorns. The acorns of other oaks contain more tannin so they require more time and effort to make them edible. White Oak acorns have much less tannin, but even still there's enough to make them too bitter for humans to eat without treatment, which traditionally has been leaching acorn pulp in running water.

By the way, instructions for the kitchen leaching of acorn pulp appear at http://www.ehow.com/how_8427141_leach-acorns.html.

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AMERICAN HOLLY FLOWERING
On the steep slopes of moist, shadowy, well-protected ravines here occasionally you find American Hollies, ILEX OPACA, and nowadays they're flowering, as seen at https://www.backyardnature.net/n/12/120429ho.jpg.

American Hollies are a different species from the English Holly often planted as ornamentals. American Holly bears larger leaves and produces fewer fruits. Hollies come in male or female trees (they're dioecious), and you can tell from the flowers in the upper, left of the above picture that here we have a male tree. A close-up of a male flower with its four out-thrusting stamens is at https://www.backyardnature.net/n/12/120429hp.jpg.

On a female flower the stamens would be rudimentary and there'd be an ovary -- the future fruit -- in the blossom's center.

Maybe because people are so used to seeing English Hollies planted up north often it's assumed that they're northern trees. In fact, American Holly is mainly native to the US Southeast, though along the Coastal Plain it reaches as far north as southern Connecticut. Around here it's strictly an understory tree.

The fruits are mildly toxic but you must eat a lot of them to get sick. Birds, deer, squirrels and other animals eat the fruits, which are drupes bearing several hard "stones." No critter seems to relish them, though, saving them mostly to serve as "emergency food" when other foods run out. That might explain why we see hollies holding their red fruits deep into the winter.

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"BEGGAR'S LICE" ON MY SOCKS
Earlier this week mornings were so chilly -- down to 49°F (9°C) -- that I wore shoes and socks until it warmed up. You can see what my shoes and socks looked like after wandering around one morning at https://www.backyardnature.net/n/12/120429mz.jpg.

Several kinds of plants produce stickery little fruits like that and they all can be called Beggar's Lice. When I tracked down the plant attaching its fruits to me, it was what's shown at https://www.backyardnature.net/n/12/120429my.jpg.

Several beggar's-lice-producing plants are similar to that, so before being sure what I really had I had to "do the botany." Here are details I focused on:

Leaves and stems were hairy, and leaves were rounded toward the base, sometimes clasping the stem, as shown at https://www.backyardnature.net/n/12/120429mw.jpg.

A close-up of a "beggar's louse" is shown stuck in my arm hairs at https://www.backyardnature.net/n/12/120429mx.jpg.

That last picture is sort of tricky. For, you expect the thing stuck to you to be a fruit with hooked spines, but the thing in the picture isn't a fruit. It's actually a baglike calyx surrounding much smaller fruit-like things. I crumbled some calyxes between my fingers and part of what resulted is shown at https://www.backyardnature.net/n/12/120429mv.jpg.

The four shiny things are not seeds. Maybe you've seen that the ovary of most mint flowers is divided into four more-or-less distinct parts. Each of those parts is called a nutlet, and that's what you're seeing. But other plant families beside the Mint produce nutlets.

Our beggar's-louse-producing plant is MYOSOTIS DISCOLOR, a member of the Borage Family, the Boraginaceae, which on the phylogenetic Tree of Life is adjacent to the Mint Family. Myosotis discolor is an invasive from Europe that so far has set up residence here and there in eastern and western North America, but so far seems to be absent in the center.

The English name is often given as Changing Forget-me-not, because Myosotis is the Forget-me-not genus, and in Latin dis-color says "two-colored," apparently referring to the fact that the flowers can be white or blue, though all I've seen here are white. But, this rangy little plant you never notice until its calyxes stick to you seems to have nothing to do with Forget-me-nots, unless you look at technical features. I think some editor must have made up the name "Changing Forget-me-not." Our plant very clearly is one of several "Beggar's Lice."

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OATS ALONG THE ROAD
Wandering backroads on my bike I spotted a grass unlike the millions of others I'd passed by. You can see how it distinguished itself with its open panicle of a few oversized, dangling spikelets at https://www.backyardnature.net/n/12/120429ot.jpg.

A spikelet plucked from the panicle is shown at https://www.backyardnature.net/n/12/120429ov.jpg.

The same spikelet opened to show the florets inside the glumes at https://www.backyardnature.net/n/12/120429ou.jpg.

This is Oat grass, AVENA SATIVA, the same species producing the oats of oatmeal. Oat spikelets differ from those of the vast majority of other grasses by the very large, boat-shaped glumes subtending the florets.

Glumes are analogous to a regular flower's calyx, so in that last picture of a spikelet, the glumes are the two large, green-and-white striped items at the left in the photograph. The vast majority of grass spikelets bear glumes much shorter than the florets above them. Also, notice that the slender, stiff, needlelike item, the awn, arises from a floret inside the spikelet and not from a glum.

Remember that you can review grass flower terminology at https://www.backyardnature.net/fl_grass.htm.

The spikelets of most Oat plants don't bear needlelike awns. You're likely to see both awned and awnless kinds growing as weeds in our area. When I first saw the awns I thought this might be one of the "Wild Oat" species, for several species reside in the Oat genus Avena, and one of those grows wild in the US Southeast. However, florets of the other species bear long, brownish hairs, and you can see that ours are hairless, or "glabrous." The other species' awns also are twisted, but regular Oat awns, when present, are rigid and straight. Both Oat species are native to Eurasia.

How did that Oat plant make its way to the side of our isolated Mississippi backroad? Near where the grass grew there was a large game farm where exotic animals are kept so hunters can pay high fees to kill them. I'm betting that the animals are fed oats. Our plant was in an often-flooded spot downstream from the farm, so maybe an oat grain had washed there.

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LOESS ROADCUTS
As I wander the countryside on my old bike, one of the most eye-catching features of the landscape is what's shown at https://www.backyardnature.net/n/12/120429ls.jpg.

That's a roadcut through a special kind of very fine-grained clay called loess. The word loess derives from the German Löß. A deep mantel of loess was deposited here at the end of the last Ice Age about 10,000 years ago. Deep loess deposits occur in a narrow band of upland immediately east of the Mississippi River over most of its entire course. The loess region sometimes is called the Loess Hills. Loess profoundly affects the area's ecology. For one thing, the farther east you go from the Mississippi River, the thinner the loess is, the poorer and more acidic the soil becomes, and the more pines you get instead of broadleaf deciduous trees.

Loess is so important here, and so interesting, that years ago I developed a web portal called "Loess Hills of the Lower Mississippi Valley," at https://www.backyardnature.net/loess/index.htm.

I had hoped to engage local folks in an effort to recognize the Loess Hills as a very interesting, scenic and biologically important, distinct region with ecotourism potential, but nothing ever came from it. At that site you can learn how "loess" can be pronounced, how it came to exist here, what's special about it, and much more.

One thing special about loess is that it erodes into vertical-sided roadcuts as in the picture. People such as road engineers who try to create gentle slopes are doomed to failure. I wish my farming Maya friends in the Yucatan, who must deal with very thin, rocky soil, could see the thick mantel of rich loess we have here.

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NO MORE EMAILED NEWSLETTERS
Last weekend, Earth Day, issuing this Newsletter by email once again caused my server, FatCow.com, to remove my whole BackyardNature.net website from the Internet. They said the Newsletters had been identified as spam. FatCow has told me that henceforward if I issue more than 20-30 emails per hour they'll take down my website. However, they are giving me permission to make this one-time last mailing. Though I shall continue writing Newsletters and placing them in my online archives, future Newsletters will not be emailed.

From now on, to read the Newsletters you'll just have to remember to check out the most recently issued edition at https://www.backyardnature.net/n/.

Today's Newsletter is there now waiting for readers, with stories about Cattle Egrets, mating Box Turtles, craneflies, flowering holly trees, Beggar's Lice and more.

If you're on Facebook you can find the Facebook Newsletter page by searching for "Jim Conrad's Naturalist Newsletter." The weekly message left there will link to individual pages with images embedded in text. In today's message, for instance, you can click on "Cattle Egrets" and see a regular web page with text and a photo. I've configured my Facebook page to have a subscribe tab but so far one hasn't appeared. My impression is that if you "like" the Newsletter page, each week you'll receive a message with its link. Maybe not. I'm still figuring it out.

So, this is the end of eleven years of weekly delivered emails.

At first I was upset and annoyed, and thought of writing the 2,158 subscribers suggesting that complaints be made to FatCow at support@fatcow-inc.com. However, something interesting has happened.

Last week about a dozen subscribers accepted my invitation to check out the Newsletter's Facebook page. When they "liked" the page, I got to see their pictures, or at least their avatars. There were all kinds of folks, old and young, skinny and fat, white and brown, serious and joking, one fellow on a boat in Maine, a lady in India with a dot, or Bindi, in the middle of her forehead, someone's baby picture... What an amazing thing that all these people were interested in what I'd written!

So, in a way, FatCow.com's treatment has been a gift. It's resensitized me to my readership. Also, it's nudged me into a mental space where now I'm mentally prepared for the whole BackyardNature.net site to be removed permanently, for whatever reason they come up with. That extra sense of independence means a lot to me. Now if need be I'm ready to write Newsletters and just keep them in my computer, or write them in a notebook hidden in my trailer, or write them on leaves that I let float down the Mississippi River. I've already learned how to make ink from oak galls.

So, we're evolving here. I'm yielding when it's clear that the forces against us control critical resources, but I'm ready to experiment with new possibilities as they appear, and I continue to think, feel and write about the world around us, and share when I'm allowed to.

Good luck in your own evolutions. And thanks for these years of weekly inviting me into your lives.

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Best wishes to all Newsletter readers,

Jim