March 2, 2009
This week Karen and I visited St. Catherine Creek National Wildlife Refuge 13 miles south of Natchez and situated in the Mississippi River's floodplain. At this time of year the refuge's big, flooded fields are a paradise for waterfowl. By a very large margin, the most commonly seen bird in the fields' open water was the American Coot, FULICA AMERICANA, shown at http://www.backyardnature.net/n/09/090302ct.jpg.
Though 50 years ago in Kentucky I also saw lots of coots, coot numbers in the refuge were so impressive that I wondered whether maybe coot populations have been expanding at the expense of duck species. Maybe one reason coots are so successful is that they eat a large variety of submerged vegetation. A coot would dive briefly and come up with a mass of green, stringy vegetation several inches long, which might take a fair amount of time to swallow -- especially when other coots tried to snatch it from the diver's beak. There was so much submerged food easily available that it seemed to me coots tried to snatch food from their neighbors more for the fun of it than for the diving work they could have saved themselves.
Despite coots looking like ducks at a distance, coots aren't ducks. Ducks belong to the Waterfowl Order, the Anseriformes, containing not only ducks but also geese, swans and other ducky species. Coots are members of the Crane Order, the Gruiformes, holding cranes, rails and limpkins. Instead of having completely webbed feet like ducks, coot feet bear "scalloped" toes -- the toes' sides bearing skin flaps that fold behind the toes when the foot is passing forward through the water, but which flair out pushing against the water when the foot is moving backward. Also, instead of having flat beaks like ducks, you can see that coot beaks are higher than flatter.
What a wonderful place that refuge is. Look: http://www.backyardnature.net/n/09/090302cu.jpg.
In that picture a flock of coots is taking off from the water and you can see that they don't "jump" from the water like some duck species. Coots seem to have a hard time getting aloft, during part of the takeoff actually running atop the water, splashing noisily and picturesquely. Look at that coot in the lower right to see what a water-top-running coot looks like.
During the summer breeding season coots are found in wetlands throughout the US and southern and western Canada, but during the winter they withdraw from most of Canada and the northern US, except in the Pacific Northwest. Here they occur year round.
As a kid in Kentucky I was taught to call coots Mud Hens. Maybe they got that name by the way they bob their heads back and forth as they walk and swim, just like an old hen in a chicken yard.
I mentioned "a flock of coots" but actually there are more specific words for designating coot gatherings. Groups of coots are called "covers" or "rafts." If you could have seen how black some of the flooded fields were this week with coots, you'd agree that "a cover of coots" makes sense.
This week at St. Catherine Creek NWR wherever there were trees we saw a lot of beaver activity. At http://www.backyardnature.net/n/09/090302bv.jpg beaver have toppled a fairly tall Black Willow onto a levee, mostly debarked it and left behind lots of woodchips. The willow had had two trunks and if you look at the very base of the fallen trunk you can see that the remaining stem itself has been gnawed most of the way through and looks about to fall.
I have read that before Europeans came into North America and began killing beavers for commerce the landscape and its ecology was much different from now because beaver had dammed almost every stream, with the dams supporting vast communities of plants and animals, and altering the water tables. The presence of beaver not only encouraged a level of wildlife activity we can only imagine now, but also contributed to long term drainage patterns, and thus the form of the landscape itself.
A FLOATING LIVERWORT
Liverworts are non-flowering, spore-producing plants closely related to mosses. Mostly you see them where mosses are growing, especially moist, shaded boulders and stream banks protected from the wind. At St. Catherine Creek NWR this week I took a close look at some "green scum" the wind had blown up against a levee and found the unusual aquatic liverwort shown at http://www.backyardnature.net/n/09/090302lv.jpg.
The five largest items in the picture are immature aquatic liverworts, a species sometimes known as the Purple-fringed Riccia. It's RICCIOCARPUS NATANS. The smaller surface-floating plants surrounding the liverworts are duckweed, genus Lemna, probably Lemna minor.
I'd been cued to look at surface-floating aquatics because along the road Refuge signs asked boaters to clean their motors well before leaving because the lake we were next to was contaminated with an aquatic fern, Salvinia, and they didn't want Salvinia to get started elsewhere. I found no Salvia. It looks a bit like our liverwort and I'm halfway wondering if maybe there's been a misidentification, for Salvinia has more of a reputation as an invasive aquatic weed than Ricciocarpus natans. You can see Salvinia's similarity at http://www.agric.wa.gov.au/ikmp/images/salvinia.gif.
Our liverwort's most obvious field marks are its free-floating nature, its flattened body, or thallus, about the size of a thumbnail, and the way the veins in its thallus dichotomously divide -- a vein forks at its tip, then the new vein forks, etc. The thallus's underside bears long, dark brown to purple scales. Spore-producing sporangia sometimes appear along the furrows cutting across the thallus's top, but spores seldom are produced, the plant mostly reproducing by dividing the thallus.
Ducks and other wildlife eat duckweed, so I suppose they also eat Purple-fringed Riccia, though I can't find literature saying so. Most people, if they know about our liverwort at all, it's because aquarists occasionally grow them to provide anchorage for the bubble-nests of such fish as Bettas and Gouramis, and then as protection for the fry.
Though my impression is that Purple-fringed Riccia is seldom if ever common, it shows up here and there across the world.
"BUTTERWEED'S" BRIGHT SPLASHES
At http://www.backyardnature.net/n/09/090302gr.jpg you see Karen looking for fossils on the gravel road through Catherine Creek NWR. Between her and myself lies a splash of yellowness providing a springy feeling to the otherwise gray and brown landscape (though note some of the trees beyond slightly tinged green and red with spring growth).
The inset at the picture's far left shows the plant producing the yellowness. That's "Butterweed," PACKERA GLABELLA. I put "Butterweed" inside quotation marks because several plants go by that name. Another name sometimes used for it is Groundsel. This is a good plant to know because it's often abundant, producing one of the earliest unmistakable signs of spring, especially for those who see "nature" only from their car.
At http://www.backyardnature.net/n/09/090302gs.jpg you see a close-up of an opening flower head (on the left) and a completely open one. The open one shows us that this "Butterweed" is a member of the Composite or Sunflower Family, for you're actually seeing many flowers packed together in a single "composite" head.
I've always placed this species in the genus Senecio, so finding out that recent studies have shifted it and a few other Senecio species into the genus Packera was a surprise. The species is native to the US Southeast and a little beyond.
COCKLEBUR LOOKING IMPRESSIVE
When I was a kid on the Kentucky farm cocklebur and foxtail grass were the two main weeds plaguing our soybean fields. On the banks of levees beside St. Catherine Creek NWR's flooded fields I saw that cockleburs continue to be a problem today, as shown at http://www.backyardnature.net/n/09/090302co.jpg.
There were miles and miles of levees and miles and miles of cockleburs at the water's edge. Of course the plants in the picture are dead, for cockleburs are annual plants. However, dead cockleburs retain stiff stems that hold the spiny fruits up well into spring, the idea being that the fruits will latch onto a passing animal's fur and be carried to a new location. You can see how well equipped a bur is for that job at http://www.backyardnature.net/n/09/090302cp.jpg.
Cocklebur taxonomy is a matter of debate, some specialists recognizing only three species in the genus and others many more. The species pictured here is surely the Common Cocklebur, XANTHIUM STRUMARIUM, native to North America despite its aggressive weediness here.
SPANISH MOSS DISPERSING SEEDS
In our upland forests often you can go for a long time without seeing Spanish Moss, TILLANDSIA USNEOIDES. I think that that's because our oak/pine forests have been logged frequently by clearcutting, or cutting ALL the trees, and when that happens sunlight and drying air currents keep Spanish Moss from reestablishing on the new generation of trees. In contrast, along area highways where loggers have left a few trees to get old, Spanish Moss is common, sometimes abundant. You can see a Spanish Moss-mantled tree in the refuge at http://www.backyardnature.net/n/09/090302ti.jpg.
Spanish Moss isn't moss at all. Mosses reproduce with spores and have no flowers, fruits or seeds. Spanish Moss is a member of the Pineapple or Bromelia Family, the Bromeliaceae, which we saw a lot of in Mexico. As such, Spanish Moss produces flowers, fruits and seeds, though most people who live around it all their lives never notice any of it. You can see fuzz-footed seeds being released from a three-celled capsular fruit at http://www.backyardnature.net/n/09/090302tj.jpg.
In that picture the seeds are the tan colored, rice-grain-like little items dangling from white stalks emerging from a dense cluster of white hairs. The seeds may remind you of Dandelion seeds (which actually are fruits) with their white parachutes. The big difference is that Dandelion fruits bear their parachutes atop them, while here the parachutes arise at the base of the stalk atop which the seeds grow. The whole fruit is a bit less than an inch long.
I have to tell you about that genus name, Tillandsia. Linnaeus established that name in honor of Elias Tillands who, my old Grays Manual tells me, "as a student crossing directly from Stockholm, was so seasick that he returned to Stockholm by walking more than 1000 miles around the head of the Gulf of Bothnia." It's thought that the joke was that since this new group of epiphytic, North American plants obviously hated water, they should be named after Tillands who was famous for his hydrophobia.
THE NATIONAL WILDLIFE REFUGE SYSTEM
At http://www.backyardnature.net/n/09/090302sk.jpg you can see a typical view across flooded fields at 26,000-acre (10,500 ha) St. Catherine Creek National Wildlife Refuge. Up front coots are feeding, while in the background numerous ducks fly by. I'm not sure what kinds of ducks they are, but most of the ones who came close enough for identification turned out to be Pintails.
When I lived near the refuge as a hermit, during hunting season it was easy to imagine the whole area being managed as a shooting gallery for duck hunters. However, once hunting season is over, what you see at the refuge is pretty impressive. A basic premise for the refuge is to provide habitat for overwintering and migratory waterfowl in the heart of the Mississippi Migratory Flyway. During the summer fields are planted with crops, then during the winter a system of canals, dikes and levees flood the fields, creating perfect duck habitat.
The refuge is managed for more than ducks. Once I entered an abandoned barn on the refuge to find mouse-infested bales of hay stacked inside. My first thought was that anyone should have known that hay on the ground in a place like this would attract mice, and then right past my head flew a Barn Owl. Apparently a manager had known exactly how to make a nesting Barn Owl happy by attracting mice to right below her nest.
The refuge also provides habitat to Least Terns and Fat Pocketbook Mussels, both listed as endangered species here. At least two active Bald Eagle nests are located on the refuge. Recent research at the refuge has focused on Black Bear, Fat Pocketbook Mussels, Rafinesque Big-eared Bats, Wood Storks and invertebrates in shorebird feeding areas.
These kinds of management and research programs seem to be having good effects. Preliminary results from the U.S. Fish and Wildlife Service and Canadian Wildlife Service's Waterfowl Breeding Population and Habitat Survey indicate a 24% increase in duck numbers over the 1955-2006 average.
The US refuge system now includes more than 150 million acres in 550 national wildlife refuges and other units of the Refuge System, plus 37 wetland management districts. If you're interested in seeing which national refuges are located in your area, check out the map at http://www.fws.gov/refuges/.
The US Fish & Wildlife Service official page for St. Catherine Creek National Wildlife Refuge is at http://www.fws.gov/refuges/profiles/index.cfm?id=42640.
TWAYBLADE ORCHID FLOWERING
Fairly common emerging from the dry leaf litter of pine/oak woods around here is the little orchid shown at http://www.backyardnature.net/n/09/090302la.jpg.
That's the Southern Twayblade, LISTERA AUSTRALIS, and most people -- even those spending a lot of time in the forest -- never notice it because it's so small and blends so well into the jumble of leaf litter around it. The visible part of the plant consists of two oval, thumbnail-size, cotyledon-like leaves topped by a four-inch-tall, raceme-type flower cluster. In the flower pictures the two-pronged, beardlike part of the corolla hanging down is the "lip" and it's only 0.4 inch long (10 mm).
In the picture's middle inset the yellowish T-shaped item at the lip's top is a nectary -- a nectar-producing gland. There's another at the base of the "column," or "gynostemium," which is the structure formed by the fused male and female parts, and the main thing making an orchid an orchid. In the pictures, it's the small lip extending outward directly above the yellow-T nectary.
When a pollinator visits the flower it touches trigger hairs on the column (there are four hairs). A dab of glue squirts onto the insect, tiny packets of fused pollen grains called pollinia are dropped onto the glue, and the insect flies off with the orchid flower's male pollinia glued to it. Ideally the pollinia are carried to the female part of another Southern Twayblade's column.
Often an orchid flower's strange form and color can be explained in terms of the flower looking look like a particular female insect, so that when a male comes along and tries to mate he pollinates the flower instead. That doesn't seem to be the case with Southern Twayblades, the main evidence being that the nectaries are easily accessible by many kinds of insects. The nectar is said to be fetid-smelling, being particularly attractive to insects such as fungus gnats and tiny flies.
The Orchid Family, the Orchidaceae, is the largest of all flowering plant, or angiosperm, families. In this area where members of the Grass and Composite Families are so abundant, and orchids are generally overlooked, most people find that hard to believe. However, once you see how common they are in the tropics, and how many habitats they occupy, you become a believer.
Southern Twayblades are distributed throughout the US Deep South, plus they exist in New York and adjacent Canada. This is a curious distribution pattern causing me to think that there may be two distinct but identical-looking species. Moreover, most literature I've seen describes the species as living in low, moist woods, marshes and sphagnum bogs and preferring acid soil, but here they definitely live in our dry, loess-covered uplands where the soil isn't at all acidic.
Whatever the case, what a pleasure to see this little orchid pop up so early in the spring. Back in my hermit days near here I reported on finding Southern Twayblades flowering just a week after we'd endured temperatures of 17°F (-8.3°C). Twayblades may look delicate but they're obviously tough little things.
CHRISTMAS FERNS UNFURLING
Christmas Ferns, POLYSTICHUM ACROSTICHOIDES, are abundant throughout our upland oak/pine woods and since their large, dark-green fronds last throughout the winter nowadays they form very conspicuous clumps of greenery emerging from the forest floor's brown leaf litter. This week it's been warm enough -- sometimes into the low 80s -- for some but not all of the ferns to issue their fiddleheads, as shown at http://www.backyardnature.net/n/09/090302cf.jpg.
"Fiddleheads" is the correct name for the emerging fronds, as you can see at the left in the above picture. As is typical for ferns, the fronds unfurl as they emerge. However, as the frond on the right shows, not all unfurling fronds always assume the classic fiddlehead form.
You can see that Christmas Fern fiddleheads are pretty shaggy affairs. A couple of nights after the above picture was taken the temperature dropped below freezing and I'll bet the fuzziness kept many new fronds from being frostbitten.
For, the fronds are actually fairly tender. In fact, I've read that in the old days people gathered them at this stage and cooked them as you might asparagus. I've tried that and found the fuzziness a bit unpalatable, plus the fronds themselves were a little bitter. However, during hard times hungry people would be glad to have them.
WINGED ELMS FRUITING
In the recent February 2 Newsletter archived at http://www.backyardnature.net/n/w/wing-elm.htm I showed you the Winged Elm's flowers as they emerged far in advance of leaves. Now beneath those same trees in many places it looks like someone has scattered green confetti, for the trees are dropping their fruits, or samaras, en masse. Sometimes when a breeze comes along they fall in showers. You can see some fruits still dangling at the ends of branches at http://www.backyardnature.net/n/09/090302we.jpg.
American Elms are producing similar samaras at this time. Since most of our larger Winged Elm trees bear wingless, leafless twigs looking a lot like American Elms, it's good to be able to distinguish the two similar species' samaras.
Mainly, Winged Elm samaras bear those very long white hairs along the edges. Hairs on American Elm samara rims are shorter, and Slippery Elm (also common here and also fruiting now) has no hairs on its fruit rims.
Also, notice that the flat faces on the Winged Elm samaras bear some short hairs. American Elm samaras are hairless, or glabrous, on the faces above the seed.
These seem like very obscure details, but when you need to distinguish species and all you have is samaras, you're glad to know about such things.
Karen's azaleas are flowering, as you can see at http://www.backyardnature.net/n/09/090302az.jpg.
That particular plant stands right outside my computering window so you can imagine how frequently during the day I rest my eyes on it.
As often is the case, once you start paying attention to the world of azaleas, you get drawn into it. It's such a huge and esthetically pleasing world that some people specialize in azaleas, like some birders just are interested in wood warblers.
In the picture you can plainly make out the flower's ten purple-anthered, pink-filamented stamens, and the longer, more curving, pink, stigma-topped style arising amongst them.
Azaleas belong to the genus Rhododendron, of which about 1000 species are recognized, mostly native to temperate regions of the Northern Hemisphere. North America has 16 native azalea species, mostly in the Southeast. Most azaleas bought at garden centers are not native species, but hybrids developed from various, frequently Asian species.
Karen THINKS that the azalea in the picture is horticulturally known as "Pride of Mobile," but she provided that name with trepidation because Garden Club ladies around Natchez take these matters seriously. "Pride of Mobile" is the exact "old-time" azalea species that must be grown around your antebellum mansion if you want everything to be historically accurate, and the Garden Club ladies do.
On the Internet I find that "Pride of Mobile" is one of several cultivars of the "Southern Indian Hybrid" group, also known collectively as the "Indica Azalea, Rhododendron x Indica. I read that Indica Azaleas were "developed from a large collection of Belgian Indian hybrids in the Southeastern US around 1870. It is a mixed group, including forms and hybrids of R. indicum X R. simsii and 'Mucronatum' forms X R. indicum."
Using Bailey's Manual of Horticultural Plants I key out Karen's azalea to the general vicinity of that cluster of species, though her plant doesn't fit any of the species descriptions perfectly. When I search for photos of "Pride of Mobile" on the Internet flowers of various shades turn up, some with five stamens and some with ten, but all looking more or less like Karen's plant.
I suspect that around Natchez's mansions nowadays there's a variety of "Southern Indian Hybrids" with varying pedigrees and varying numbers of stamens, all being called "Pride of Mobile," and really there's not much use debating what's the "pure 'Pride of Mobile.'" By now the genes are too scrambled to be dogmatic about it.
If you'd like to get addicted to azaleas, browse through the Azalea Society of America's website at http://www.azaleas.org/index.pl/azaleas.html.
This week's springy weather couldn't have been more pleasant. The still-flowering plum tree's fragrance on warm, moist winds, the greening forest, birds ever more melodious... Everything has been so lush, tender and expectant that on certain levels it was disorienting. The onrushing spring avalanche lavishes us with sensory overload, but why?
We tell ourselves that such questions as "Why does spring feel so good?" are unanswerable. They arise from the false premise that everything has to be explained rationally.
However, this week Kathy in Vermont sent me an essay by Jennifer Ackerman about the Japanese practice of shinrin-yoku, or "Taking in the Atmosphere of the Forest," in which maybe an actual answer is being provided. You can read the whole article yourself at http://wilderness.org/content/can-stroll-ward-off-cancer.
The article reports that a Japanese study comparing the physiological effects of walking in the city with strolling in an old-growth forest found that the forest stroll not only lowered blood pressure and heart rate but also improved immune function. These and many other findings add to a growing body of evidence that "forest bathing" can affect everything from blood glucose levels to the activity of immune cells, maybe even help protect against cancer.
In fact, in Japan there's a whole "Forest Therapy" movement, as described in "The Japan Times" story at http://search.japantimes.co.jp/cgi-bin/nn20080502f1.html.
That article quotes an expert as explaining "Humans had lived in nature for 5 million years. We were made to fit a natural environment. So we feel stress in an urban area. When we are exposed to nature, our bodies go back to how they should be."
Maybe this week my senses have been scrambled, massaged and sharpened because in my body I've been getting things "back to the way they should be."
Actually, I've believed this for a long time. For years one of my dreams has been to settle someplace where I could help people feel better and be healthier by interacting with Nature.
I still regard that as a good idea but I've never been able to get any such program off the ground.
Therefore, if anyone out there knows of an organization, a health spa, a refuge or park with an old shed I could stay in, a school with a woodlot, or whatever -- interested in brainstorming with me on developing a "Nature Therapy" program where certain healings would be attempted through the agency of "forest bathing," studying flower anatomy and such, please suggest that they contact me.
Meanwhile, I'll be here as Spring massages, renews, invigorates and just makes me feel good.
Best wishes to all Newsletter subscribers,