September 6, 2009
A GOOD TIME FOR FINCHES
Here at the dry season's end the landscape mellows into endless ripenings of seed and fruit. In rural areas along roads and field edges, grasses offer a bounty for grain eaters. Everywhere elegant grass inflorescences nod in breezes, holding aloft tiny, hard grains enfolded in dry, dun-colored chaff, the neat glumes, lemmas and paleas of grass flowers. It's a good time for small songbirds who land among the flimsy inflorescences and eat the grains, spending much time grinding their beaks back and forth husking off the chaff and mashing the seeds.
No bird group is more at home inside a grass inflorescence than the Finch Family, and in North America maybe the best-known and most beloved finches are the bright yellow and black goldfinches, the American Goldfinch distributed from coast-to-coast, and the Lesser Goldfinch of the west and south-central states.
During this week's backpacking hike for the first 15 miles I walked along roads through the valley before climbing into mountains and following Forest Service logging roads back home. Again and again small flocks of Lesser Goldfinches, CARDUELIS PSALTRIA, turned up wherever grasses had gone unmowed, and in blackberry thickets. There's so much for them to eat that often long rows of them perched basking on power lines above their meals. Two perching on a line are shown at http://www.backyardnature.net/n/09/090906lg.jpg.
The mature male on the right calls his thin, high-pitched teeeyooo as the juvenile on the left seems to be rolling his eyes like any good adolescent. Of course that's grossly anthropomorphic, so you can interpret the image yourself.
Lesser Goldfinches are so named because they're half an inch (1+ cm) smaller than American Goldfinches, who are small birds to begin with. You can distinguish the male Lesser in the picture from a mature male American Goldfinch because the black on the latter's head is restricted to the forehead, while the Lesser's blackness continues over the crown and down the back.
Lesser Goldfinches are common in upland central Mexico, too, but Americans don't get that far south. Down there, male Lessers have pure black backs, while you can see that our male's nape pales to a greenish gray. Our pale-backed geographical variation is limited to the US far West, and northwestern Mexico.
A SPIDER'S SPICED WEB
The most conspicuous spider here nowadays produces a dome web strung at head level between limbs of bushes along roads and at woods edges. It's the Sierra Dome Spider, NERIENE LITIGIOSA, native to the northwestern US. An upside-down female beneath her dome is shown at http://www.backyardnature.net/n/09/090906sh.jpg.
You can see a close-up ofthe pretty spider herself at http://www.backyardnature.net/n/09/090906si.jpg.
Sierra Dome Spiders are polyandrous -- females usually mate with more than one male. Females "spice" their webs with male-attracting pheromones. Once male and female meet they engage in 2-6 hours of "pre-insemination copulatory foreplay," copulation consisting of the male inserting his sperm-holding, sink-plunger-like palps (leg-like appendages often serving as "feelers" near the head) into the female. Courtship works up the male so that his metabolic rate rises 1.2-4.5 times his resting rate. Once the session ends the male retires to the web's edge, deposits more sperm into one or both palps, and returns to copulate for another 0.5-1.4 hour, during which 60-120 additional sperm insertions take place. This information is from an online book review of "Cryptic Sexual Selection -- More Control Issues," an article appearing in "Evolution 51(1), 1997, pp. 321-324."
The rambunctious courtship enables the female to judge how vigorous the male is. Females prefer strong fighters. If no exceptional fighters are available, large, vigorous males come next. An abstract of a paper with more detail on mate choice can be read at http://www.ncbi.nlm.nih.gov/pubmed/9480706.
In an effort to be surer that the female accepts their sperm and not the sperm of another male who comes along later, males often destroy much of the female's pheromone-emitting, other-male-attracting web. Of course this isn't helpful to the female, since not only does she want the web to attract more males but also she uses the web to catch her food; she'll have to rebuild it. Information about this species' spiced webs is in the online Google book Sexual Conflict By Göran Arnqvist & Locke Rowe, Princeton University Press, 2005.
Having learned the above details I took a walk looking at every web I could find, maybe a dozen during a half-hour search. Several webs appeared to be empty. One had the dome completely ripped away and in other webs large sections were missing and I wondered whether males had been at their web-wrecking business there. In one, the female sat sucking the juices from what seemed a smaller spider. And in just one, the female waited upside-down beneath her perfect dome, waiting for some action.
A DARK LITTLE HOVERFLY
Spotting a smallish, darker-than-I'm-accustomed-to-seeing hoverfly on Anita's Alyssums I snapped the shot at http://www.backyardnature.net/n/09/090906hf.jpg.
So, what's that dark, rice-grain-shaped thing emerging from the fly's side? Luckily I'd taken several pictures and one of them showed that the fly actually has two of them, as you can see at http://www.backyardnature.net/n/09/090906hh.jpg.
I was in a rush that day preparing for a hike so I shipped the images off to Bea in Ontario who very quickly responded that probably this was a SYRITTA PIPIENS, and that the elliptical things definitely are the fly's overgrown leg femurs! In the first picture the lower part of the leg is invisible but in the second the lower segments are clearer. I had to blush over that.
One English name for the fly is the Thick-legged Hoverfly. It's a member of the family Syrphidae, which holds a number of mostly yellow-and-black, stingless, hovering little flies generally known as flower flies and syrphid flies.
It turns out that male/female interactions in Syritta pipiens is as remarkable as that with the Sierra Dome Spider.
When males chase females they approach the female at a certain close distance but don't get so close that the females take evasive action. As the female leads the chasing male, the male always stays at exactly the same distance. Insect nervous systems react mostly to changes in size and movement, not to something that appears to be an unmoving spot, which is how the male looks to the female. The male's strategy employs a kind of "motion camouflage."
Moreover, if the female changes direction, the male flies sideways without changing his heading, which denies the female a chance to see the male with a different profile, from the side. No matter how the female flies, the male remains a same-size, same-shape speck behind her, and her eyes and brain just can't make anything of that.
When finally the female lands, the male already is close enough to pounce. You can read more at http://www.springerlink.com/content/v3217l83924621j7/.
Syritta pipiens enjoys an enormous distribution, being native to the Palearctic region, which is one of Earth's eight biogeographic zones and embraces Europe, the northwest coast of Africa, and Asia north of the Himalayas. The species been introduced into North America; here Syritta pipiens is an invasive "weed species."
WHITE ALDERS AT THE POND
In a marshy spot beside the pond a 20-ft White Alder, ALNUS RHOMBIFOLIA, bears this year's green "cones" as well as last year's brown, open ones. This year's are at http://www.backyardnature.net/n/09/090906al.jpg.
Alders, members of the Birch Family, bear male and female flowers separately but on the same tree. Male flowers emerge in the spring in slender catkins while female flowers occur in shorter, pistillate catkins. The mature pistillate catkins are often called strobili (singular strobilus or strobile). You can see last year's open, empty strobili still on the tree at http://www.backyardnature.net/n/09/090906am.jpg.
Alder leaves are similar to those of other members of the Birch Family -- birch, hazelnut, hornbeam, hophornbeam. Alder catkins/strobili are completely different, though. Eastern North America also has its alders but they are shrubs or rarely small trees.
White Alders are wonderful trees, fast-growing, lush trees needing lots of sunlight and water. They're prettily formed, so dense that they produce a chilly shade, and even their leaves are somewhat fragrant if you bruise them. To top all that off, alders have a symbiotic relationship with the nitrogen-fixing bacteria Frankiella alni, which convert atmospheric nitrogen into soil-soluble nitrates used not only by the alder but also by the surrounding general plant community.
Medicinally, Alder-leaf infusions have been used against fleas, for burns and as an eyewash. Native Americans used the tree's straight shoots for arrows, wove its roots into baskets, and made red dye from its bark.
White Alders are native from Washington State through California, east to Montana and Nevada.
ALDER TONGUE GALLS
Some catkins on the White Alder shown above were infected with fleshy, green and red Alder Tongue Galls caused by the fungus TAPHRINA AMENTORUM. They're shown at http://www.backyardnature.net/n/09/090906ag.jpg.
Most galls I know are produced by insects. The female inserts an egg someplace, cells around the egg then begin multiplying, producing remarkable, typically fleshy structures -- the galls -- and then when the insect larva emerges from the egg it has a lot of fleshy vegetable material to eat. But Alder Tongue Galls result when immature catkin scales are infected with the fungus, which later produces spore-producing fruiting bodies on both gall surfaces.
Of the seven phyla of fungi, Taphrina amentorum belongs to the Ascomycota, so it's related to the mildews, molds and morel mushrooms. In the old days they were referred to as Sac Fungi
Up at the pond there's a weedy-looking aquatic emerging from the water and topped by spike-like racemes of little white flowers. You can see it emerging from the pond's surface choked with pondweed at http://www.backyardnature.net/n/09/090906po.jpg.
That's Swamp Smartweed, sometimes called Mild Waterpepper, POLYGONUM HYDROPIPEROIDES, and it also grew in the pond below my old hermit trailer back in southwestern Mississippi; it's native coast-to-coast in North America. The flowers, only about 1/10th-inch across (3 mm), are usually white but often suffused with pinkness.
At http://www.backyardnature.net/n/09/090906pp.jpg you see a blossom with six petal-like perianth lobes (perianth is the combined calyx and corolla), six stamens, and three stigma-topped styles arising from the three-angled ovary hidden down below. Having flower parts in threes or multiples thereof is a little unusual for dicot flowers, but fairly common in the Buckwheat Family. Most dicot flower parts occur in 5s or 4s, or multiples thereof.
The Buckwheat Family is known by another good field mark that's even visible on non-flowering plants. You can see it on our Swamp Smartweed, looking like a papery, bristle-topped, brown sleeve surrounding the stem at the base of a leaf petiole, at http://www.backyardnature.net/n/09/090906pq.jpg.
We've often referred to the tiny-leaflike stipules at the base of certain leaves, such as the earlike, gland-rimmed ones we saw on a willow stem last week. In the Buckwheat Family the stipules have grown together into that cylindrical sheath surrounding the stem at nodes ("stem joints"). Often these sheaths bear at their tops conspicuous hairlike features like those in the photo. Such a sheath at a stem node is known technically as an ocrea (plural, ocreae).
Swamp Smartweed stems are weak, often branched affairs growing through the water, often issuing white roots at their nodes. The plants are perennial, arising from rhizomes. The plants' 0.08-inch long (2 mm), hard, brown, shiny, three-cornered fruit, an achene, is a mainstay duck food, and other birds and small animals eat them, too.
Even on seldom used trails deep in the mountains you run into Bull Thistles, CIRSIUM VULGARE, beside the road. Usually there's just one plant. They've been flowering for weeks so now mostly their heads are white with parachuted seeds occasionally abandoning themselves singly or in groups into the wind. You can see a plant with both a fruiting and a flowering head at http://www.backyardnature.net/n/09/090906ca.jpg.
At the base of the plant at the left in the photo there's a small rosette of spiny leaves. Bull Thistles are biennials -- living two years -- who produce a rosette the first year, then on the second year a stem arises from the rosette. Therefore the inset actually shows two plants, a tall, second-year one and a first- year one in its rosette stage.
The Flora of North America describes 62 thistle species in the genus Cirsium, plus spiny plants in other genera also are referred to as thistles. An important field mark for Bull Thistles is shown at http://www.backyardnature.net/n/09/090906cb.jpg.
There you see that the hairy stem is "winged" -- bears narrow vertical ridges of green tissue extending from the bases of leaves down the stem. The wing on the stem's left is evident because of how light passes through its thin tissue.
Windborne thistle seeds are parachuted with feathery branched hair -- thistledown -- as you can see at http://www.backyardnature.net/n/09/090906cc.jpg.
Notice that the spent purple corolla still is attached to the "seed" (actually an achene-fruit), its slender tube rising above the hairs.
Bull thistles are native to Europe, western Asia, and northern Africa. They are thought to have been introduced into the eastern US during colonial times and into the West during the late 1800s. Currently it's found in all 50 states and it's not liked at all by livestock people because of the damage it can do to a grazing animal's mouth.
For about a month as I've been watering Anita's flower garden each morning I've been watching some fungi develop. They look like brown potatoes lying on the moist ground below a pot's overflow tap, as you can see at http://www.backyardnature.net/n/09/090906sc.jpg.
I'd assumed that they were puffballs -- that on their tops eventually holes would develop where spores would escape, but instead the things began developing cracks with no signs of holes. To figure things out I had to pick one, and the moment I had one in my hand I knew that it was no puffball: It was too hard and too heavy for that. I cut one open and saw what you can see at http://www.backyardnature.net/n/09/090906sd.jpg.
Not a puffball, this, but something close to it, something sometimes called an earthball, a fungus of the genus SCLERODERMA. Species are separated in Scleroderma mainly on the basis of spore shape, which I can't see, but my specimens' form, habitat and external appearance suggest that they may be Scleroderma cepa, or close to it.
The first time you recognize an earthball you think you've discovered something extraordinary, but once you have an eye for what they look like suddenly they show up all over the place; you've just been overlooking them. Even in the most ecologically ravaged urban apartment zone sometimes earthballs show up in abundance emerging from woodchip mulch strewn around ornamental shrubs and trees planted it and around parking lots.
The dark purple mass in the earthball's center eventually matures into a mass of dry spores, similar to what happens with the puffballs. However, no exit pore for the spores ever develops. The fungus's leathery cover simply gets progressively thinner and more brittle as the dark purple, firm, heavy spore mass -- the gleba -- dries into a powdery mass of dusty black spores. This week while thinning the strawberry beds I found several old ones that practically shattered when I poked them, releasing clouds of spores.
How would their spores ever have escaped if I hadn't come along? One earthball had completely collapsed into a messy black pile and I'd never have noticed it if I hadn't been watering the garden, and puff's of spores erupted from the pile each time a drop of water hit. Maybe this fungus's strategy is simply to wait for some random event to shatter it, releasing its spores, depending on some feature of chaos the human mind finds it hard to grasp.
Members of the genus Scleroderma are "ectomycorrhizal fungi," which means that their threadlike mycelium forms a sheath around a host plant's root tip, with both the fungus and the host benefiting from the resulting symbiotic relationship. Mycelia are the white fungal strands you see growing through humusy soil like roots, decomposing organic matter as they go.
The ectomycorrhizal relationship is regarded as one of the most ecologically and economically important of all of Earth's natural relationships. Therefore, these humble-looking little earthballs are to be respected for the services they render us all. Read more about it all at http://www.nifg.org.uk/ecto.htm.
Most sources regard earthballs as poisonous or at last undesirable for eating.
A GENUINE PUFFBALL
More "little brown potatoes" grew beneath some lilies in one of Anita's raised boxes but once I'd been sensitized to earthballs I began questioning whether they were the same thing, for they were consistently smaller and with a more mottled skin, as you can see at http://www.backyardnature.net/n/09/090906cv.jpg.
As soon as I picked one I could tell that it was much softer and lighter than the earthballs. However, neither did these show signs of producing an escape hole for the spores. A cross-section is shown at http://www.backyardnature.net/n/09/090906cw.jpg.
This one's skin is much thinner, there's a thick, white "stem" area, and the spore mass, or gleba, is brown instead of dark purple. Searching beneath the lilies I found old ones showing that upon maturity the fungus's fruiting body cracks and the resulting fragments peal back fairly haphazardly, enabling the spores to escape.
I'm 80% sure that this is CALVATIA CYATHIFORMIS, often known as Purple-spored Puffball, even though in my picture the gleba is brown. On the Internet other of this species often show the same brown color so I don't know what the deal is.
Calvatia mushrooms, considered to be genuine puffballs even though the have no holes in their tops through which spores can puff, are saprobic, which means that they feed on dead organic matter. This species is commonly found in lawns, pastures, golf courses and prairies. Often it forms fairy rings, or circles. The best known Calvatia is the Giant Puffball, one of which we encountered back at Polly's Bend in central Kentucky, still shown at http://www.backyardnature.net/n/x/puffball.htm.
It's interesting that this Calvatia puffball and the earthball are only distantly related species yet they've turned up in the same place at the same time looking so alike. I'm supposing that it's the old case of a specific growth form and appearance being optimal for any particular ecological niche, the niche here being much-watered garden soil.
When young with a white gleba this puffball is edible and good tasting.
Anita is especially busy these days canning fruits and vegetables. Her pantry is a pleasure to look at, filled with colorful jars of canned red tomatoes, purple beets, green pickles and snapbeans, orange squash, yellow peaches, and more. You can take a peep at http://www.backyardnature.net/n/09/090906ac.jpg.
THE ARTFUL CREATOR
The vast majority of tadpoles in the pond above my trailer must die before they mature into frogs. If they don't, the pond's ecology will be thrown out of whack by too many bullfrogs. This kind of situation appears again and again throughout Nature. Therefore, wouldn't a philosophy based on patterns in Nature accept that most innocent humans also must suffer endless indignities, miseries and death as they make way for "the stronger," the "more adaptive," or the luckier?
Not necessarily. It's our genes predisposing us to breed obsessively, to crave high-calorie foods, and seek ever-higher status -- to mindlessly do those things at the root of most of our indignities, miseries and early deaths. Yet, of all animals on Earth, we humans are the only ones able to thoughtfully behave in ways contrary to our genes' programming.
One reason it's hard for humanity to overcome its programming is that all great cultures rest on religious underpinnings, and our religions have arisen in antiquity, too. Too often they convey the unsustainable patriarchal and tribal mindsets they arose in, plus they always fail to address such modern realities as human overpopulation, overfishing the oceans, and the buying of unneeded things the production of which creates pollution and contributes to global warming.
Maybe an even more critical deficiency of established religions is that especially Western ones promote the notion of a benevolent patriarchal divinity watching over us and prepared to save at least the "good" among us from our follies and bad luck.
That concept is lethal. It's lethal because, at least at a powerful, subliminal level, it encourages us to "pray for deliverance" and to hope that "divine intervention" will save us, instead of our taking responsibility for our own long-term biological survival.
Instead of "Our Father, who art in Heaven," it would be wiser to revere "Our Creator, who makes art everywhere... " the artful Creator being more concerned with abstractions such as the evolutionary flow toward ever-greater diversity, ever-greater sophistication, ever-greater sensitivity, enlightenment and spirituality... than with the day-by-day welfare of individuals, or even individual species.
Best wishes to all Newsletter readers,
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