July 19, 2009
HOT ROBIN NESTLINGS
A couple of Newsletters ago I mentioned the nesting American Robins outside my window. Since then I've witnessed remarkable behavior.
For instance, twelve days ago at dusk I noticed both parents on the nest's edge peering inside. The male flew off, returned with a tiny earthworm, seemed to offer it to a nestling three or four times but apparently no nestling would take it, so the father swallowed it himself.
That was the last hint I had that there might be a nestling until a week later when the father arrived with an earthworm and up popped two fuzzy nestling heads with gaping beaks. And then, amazingly, the mother sitting amidst her babies also threw back her head, fluttered her wings and gaped just like her babies, begging to be fed! The male fed a nestling and flew away.
I figured that that would be the beginning of a frenetic feeding period but, no, most of this week the mother stayed most of each day on her nest, searching for worms mainly near dawn and dusk, and the male only rarely visited with worms, right before dusk. This weekend, however, the rate is picking up, and there are three nestlings, their eyes barely open.
On Thursday afternoon the temperature reached 91°. That felt pleasant to me because the humidity was very low but it seemed to stress the robins. For awhile as a hotspot of sunlight crossed the usually shaded nest two nestlings poked their heads from beneath the mother's wings and all three gaped panting but otherwise unmoving, cooling off as water evaporated from their mouths' moist membranes, as you can see at http://www.backyardnature.net/n/09/090719ro.jpg.
Whenever the mother plops worms into her nestlings' mouths she then bends down beneath them and scoops up their fecal pellets -- their droppings -- and swallows them. That's nutrient recycling. I haven't seen the male do this.
One of Anita's housecats got the nesting Tree Swallows I profiled a while back -- the mother and all the nestlings. The father still makes straight, high flights over the nest, looking down but never circling, never chortling, as during recent weeks.
But this robin nest has about 15 feet of open space beneath it so we'll see what happens with them.
A BUSY BLACK-THROATED GRAY WARBLER
So much nesting is taking place that it's easy to spot other bird parents of different species rushing about foraging for food, often so hectically that they're not taking the usual precautions of being extremely watchful for danger. That was the case this week as I passed a woods edge and heard a ruckus beside me inside a Madrone's stiff leaves. A Black-throated Gray Warbler, DENDROICA NIGRESCENS, was chasing a winged insect not at all interested in being eaten, and the insect kept getting away.
As I got my camera into position the wounded insect fell to the ground, the warbler fluttered downward after it, wings beating against dry leaves and twigs, and not seeming to notice me standing ten fee away. The moment the insect was subdued is shown at http://www.backyardnature.net/n/09/090719bg.jpg.
Warblers possess very slender, rather short beaks but the bird in the picture appears to have a massive, finch-like beak. Is it diseased, or tumorous? I have no idea what's going on here.
Black-throated Gray Warblers are a strictly Western species, nesting no farther east than Colorado and New Mexico. They overwinter spottily in southern California and Arizona, southward through Mexico. They look a lot like the East's Black-and-white Warblers but their gray, lightly striped backs differentiate them from that species. No similar warbler in our area bears the yellow spot before the eyes -- yellow lores -- but in the field that often goes unseen.
Black-throated Grays may be our most common warbler at woods edges and in the scrub around my trailer.
AN EASY-GOING RATTLESNAKE
Last week's hike into the higher elevations was sort of a washout. The temperature stayed in the low 50s and it was so drizzly and dark that I couldn't photograph, so I just turned around and began hiking back into the valley, head bent low to keep the rain off my glasses. Then I found myself sailing through the air backwards, having almost stepped onto a Western Rattlesnake, CROTALUS OREGANUS. You can see him at http://www.backyardnature.net/n/09/090719cr.jpg.
To the snake's credit, he lay beneath a Douglas-Fir out of the drizzle, but otherwise it just didn't seem like the kind of day when a rattlesnake would be out. I guess the cold air accounted for his lethargy, for he was very slow-moving and seemed perfectly willing for me to step on him. He took his time slithering away and even when I picked him up with my walking stick, to get him out of the road, he didn't rattle, didn't strike -- in fact behaved just like somebody's pet boa accustomed to being handled.
The last time I'd run into a Western Rattler, in the Sierra Nevadas back in 2005, I'd been impressed by how excitable, fast and willing to rattle that individual had been. But that time it'd been very hot, and maybe that made all the difference. Another reason this rattler may have behaved so placidly is that a substantial, rat-size bulge arose at his mid body; he had a good meal inside him.
At http://www.backyardnature.net/n/09/090719cs.jpg you can see a close-up of his rattle. The six bands do not signify that the rattler is six years old. Rattles acquire a new segment each time the snake sheds its skin, which is normally two to four times each year. The six segments, then, would be about normal for a two-year-old rattler, and the rattler's length of a little over two feet also suggests that approximate age.
SKINK AT LAST
Already back in April when late afternoon sunlight warmed a nearby roadcut I began seeing a certain blue-tailed skink. He was a lot like the East's Five-lined Skink, but thicker and stubbier, with broader white lines. I've never had problems approaching Five-liners so I figured snapping a picture of this western species would be easy.
The skink lived in a neat tunnel about as broad as my little finger, in the roadcut's almost-vertical dirt face. One sunny afternoon I set my camera on a tripod pointing at the hole and waited. In about 20 minutes he came out and paused right beside his hole. Either the tiny movement of my finger on the shutter or the sound of the camera's motor grinding as it autofocused sent the skink rushing into his hole, yielding a blurred picture. That was when I realized that if I were to get this critter's picture I'd need some luck.
This week it finally happened. I spotted a blue tail poking from behind a bush while that same bush blocked the skink's view of me. I pulled out the camera and waited. The resulting shot, showing a Western Skink, EUMECES SKILTONIANUS, emerging from behind the bush is at http://www.backyardnature.net/n/09/090719sk.jpg.
In this part of the world there's only one skink species with a blue tail, so identifying it was pretty easy. Western Skinks are fairly common on dry slopes, especially south-facing roadcuts. The field guide says that the tail usually is gray or brown with only juveniles having bright blue ones. I've only seen blue-tailed ones so that's something to figure out.
Western Skinks feed mostly on insects, spiders and earthworms, and are distributed from southern British Columbia into Mexico's Baja California, east to central Utah.
A REALLY BIG ICHNEUMON WASP
While typing the above a winged insect flew between my face and the laptop's screen. The amazing thing about it was its size -- maybe 4-½ inches (11 cm)! The critter bumped into the window and somehow took up position on the smooth, vertical glass, as shown at http://www.backyardnature.net/n/09/090719ic.jpg.
With the awe-inspiring "stinger" at the end of its abdomen I knew that this was an ichneumon wasp. Of course that's not a stinger at all but rather a female's ovipositor used for laying eggs on, near, or inside a host's body. Upon hatching, the larval ichneumon feeds either externally or internally, eventually killing the host when it pupates.
The wasp flew out the door before I could measure it with certainty but I read that giant ichneumon wasps of the genus Megarhyssa do reach 11 cm, counting the ovipositor. As usual, I sent the picture off to Bea in Ontario with her insect savvy and fast internet connection. Bea knew enough to be wary about IDing the ichneumon to species level. She wrote back that the superfamily Ichneumonoidea has been estimated to contain over 80,000 different species and that they are highly diverse -- ranging from 3 mm (1/8-inch) to 13 cm (5 inches) long. The best Bea could do was to find someone commenting on a picture like mine, saying "I would only GUESS tribe Ephialtini (i.e, a genus closely related to Ephialtes).
BLACKCAP RASPBERRIES FRUITING
In my friends' orchard luscious cultivated blackberries are coming online and out in the mountains, especially along rocky roadsides, you can start picking "wild raspberries" -- more formally known as Blackcap Raspberries, RUBUS LEUCODERMIS, seen at http://www.backyardnature.net/n/09/090719rb.jpg.
This is an easy-to-identify species. You know that what's in the picture is a raspberry and not a blackberry, which belongs to the same genus, Rubus, because of how the black "berry" between my fingers separates so neatly from the white, conelike "core" to the fruit's right, leaving the pulpy fruit hollow. In contrast, when you pick a blackberry the white "core" remains inside the blackberry, and you eat it. The "berry" leaving behind its "core" is what makes a raspberry a raspberry. This particular species is further distinguished by its whitish leaf undersurfaces.
Above I place the word "berry" within quotation marks because botanically blackberries and raspberries aren't berries. Technically a berry is a pulpy fruit resulting from a single pistil, but not containing a true stone like a plum. The tomato, then, technically, is a berry. Blackberry and raspberry fruits are known technically as "aggregate fruits," for they derive from flowers with more than one pistil -- the pistil being the female part composed of stigma, style and ovary. A diagram showing this arrangement can be reviewed at http://www.backyardnature.net/frt_aggr.htm.
Though they don't have much taste to them, often I snack on Blackcap Raspberries as I hike along. Mostly I leave them for wildlife. Nowadays black berry-pulp is starting to show up in bear poop, and often families of California Quail are seen orbiting around blackberry thickets. This raspberry species is a fine native plant distributed from British Columbia south to Mexico's Baja California, east to Montana and Nevada.
I'd been waiting for a certain white-flowered, waist-high, thicket-forming shrub along a streamside trail to fruit before trying to identify it. It's a handsome plant with hand-sized, maple-like leaves. Nowadays it's producing conspicuous, red fruits, shown at http://www.backyardnature.net/n/09/090719tb.jpg.
When one of its pulpy, bumpy fruits is picked, it leaves its "core" behind as a raspberry would, as seen at http://www.backyardnature.net/n/09/090719tc.jpg.
And, by golly, it basically IS a raspberry. Along with Blackcap Raspberries, it's also a member of the genus Rubus, but it's the most anomalous Rubus I've ever seen. Rubuses such as raspberries, blackberries and dewberries are "supposed" to bear compound leaves on spiny stems but this species produces neither of those. It's the Thimbleberry, RUBUS PARVIFLORUS, distributed more or less throughout western North America from Alaska and Ontario to northwestern Mexico.
Though Thimbleberries are something new to me, they display such flexible habitat requirements that they are one of the most characteristic species of many northwestern forests. Ecologically the Thimbleberry serves as a pioneer species in the forest understory during the first several decades after disturbance, especially after fires. It needs a lot of nitrogen and declines within 2-5 years after timber harvesting as soil nutrient levels decrease.
Thimbleberry thickets provide cover for many kinds of wildlife and many animals eat its fruits. Indigenous peoples ate the fruits fresh in summer and dried during the winter. The bark was boiled and made into soap, and leaves were powdered and applied to burns to minimize scarring.
For a couple of weeks one of the most eye-catching wildflowers at woods edges and along backcountry roads has been the woody-based, bee-attracting plant shown at http://www.backyardnature.net/n/09/090719cm.jpg.
With its opposite leaves and dense, spherical flower head subtended by a collar of modified leaves, or bracts, you don't have to pinch one of its leaves to smell its pungent, minty odor to know that the plant belongs to the Mint Family. Sometimes you see hundreds growing like weeds along roads so I figured it must be a wide-ranging weed, and I felt a bit ashamed for not recognizing it.
It keyed out to the genus Monardilla, 28 species of which are listed in California's Jepson Manual. No Monardilla is mentioned in Weakley's Flora of the Carolinas, so this is another of those western genera Easterners just don't hear about. The plants further keyed out to MONARDILLA SHELTONII, which turns out to be endemic to just three southwestern Oregon counties and a bit of northern California. You can see some of the features distinguishing Monardilla sheltonii at http://www.backyardnature.net/n/09/090719cn.jpg.
There I've broken a flowering head in two and hold a single flower with its four stamens at the tip of my thumb. The species is very close to M. villosa, but its calyxes are not glandular-hairy, and its leaf undersides are not wooly.
In figuring out this species I was helped by the online "Google Books" site where I found Plants of Western Oregon, Wshington & British Columbia by Eugene Kozloff. This is a wonderful resource -- if you have a fast internet connection, which I don't. To find the book online, Google the title and "Google Books."
What a pleasure to find an endemic like this unlike anything I've ever seen before -- especially when there are whole roadsides of them growing like weeds!
WILD RYE/ BIG SQUIRRELTAIL GRASS
As the hot dry season progresses here the landscape fades, meadows start looking scorched, and mountain slopes show their patches where each clearcut tract displays a different degree of brownness, depending on how recently it was cut. The more recent the cut, the more herbaceous layer there is to die back, and the browner that is. Grasses are conspicuous among the non-woody plants.
One of the most showy grasses nowadays is shown at http://www.backyardnature.net/n/09/090719gr.jpg.
About 15 inches high, that's one of many grass species referred to as "wild rye," often more narrowly known as Big Squirreltail. It's ELYMUS MULTISETUS. For a couple of weeks the grass's flower heads have constituted narrow spikes but now as the stems and leaves die and dry out the flowers' long, needlelike "awns" spread out as you see. When the sun is low at dawn and dusk, sunlight very prettily catches in the heads' flaring awns.
While photographing the above plants I wondered how the long awns served the plant. Probably, even though they're not very stiff, they thwart herbivores, but another reason suggested itself when a vagrant breeze blew through: Part of a fruiting head broke off and was borne by the wind several feet away, thus disseminating the fruit into new territory.
Several grass species create similar wide-spreading fruiting heads. To be sure that what you're seeing is really Elymus multisetus, the floral anatomy must be checked. A close-up shows some of that at http://www.backyardnature.net/n/09/090719gs.jpg.
There you see that the "glumes" are divided to their bases into three to five needlelike "awns." Above the awns stand two "fertile florets," one on a "pedicel" above the other, plus there's at least one "sterile floret" at the side. The special terms are explained at http://www.backyardnature.net/fl_grass.htm.
Despite its stems dying back at this time, Big Squirreltail is a perennial. Several blackened, partly decayed stems from last year usually can be found radiating from the grasses' bases. Big Squirreltail is native to about the western third of the US, into Mexico's Baja California.
In this area the most commonly found fern is Bracken, Pteridium aquilinum, which also is the most abundant fern worldwide. I introduced you to it from Mexico at http://www.backyardnature.net/chiapas/bracken.htm.
I've also introduced you to our second-most common fern, the Western Swordfern, Polystichum munitum, at http://www.backyardnature.net/n/x/sword-fn.htm.
There I report that Western Swordfern is very closely related to, and can be hard to distinguish, from the third-most-common fern here, the Narrowleaf or Cliff Swordfern, POLYSTICHUM IMBRICANS, which now you can see at http://www.backyardnature.net/n/09/090719sf.jpg.
A close-up showing the round, spore-producing fruit-dots, or sori, and spiny-margined leaflets, or pinnae, is at http://www.backyardnature.net/n/09/090719sg.jpg.
Both of these swordferns are closely related to the East's Christmas Ferns. Around here, if you see a big swordfern in a moist valley it's surely the Western Swordfern. The Narrowleaf Swordfern is a tougher, wirier, more slim-fronded species than the Western. The pictured Narrowleaf occurs on a very dry, exposed talus slide below a roadcut. Narrowleaf Swordferns prefer drier habitats while Western Swordferns prefer moister ones. However, in in-between habitats the Narrowleaf species looks lusher while the Western species looks leaner. Then they can be hard to distinguish.
If you have sori in the stage shown in the picture, the cellophane-like "caps" atop each sorus -- the indusia -- are fringed with tiny hairs in the Western Swordfern, but are hairless or broadly toothed on the Narrowleaf. Also there are differences in size of scales on the fronds' stems, or petioles. But often there are no indusia, and the scales are of in-between sizes. Sometimes in in-between habitats with in-between ferns, I just can't distinguish them.
Narrowleaf Swordferns occur from British Columbia south through Washington and Oregon into California.
UNCLE BEAR'S DOUBLE GOLD
"Uncle Bear" in North Carolina received my Gold-level Bug-Eaten Leaf Award last November for identifying 100 plants and animals in his own neighborhood. This week he became the first ever to receive the "Double Gold" for listing 200 species. You may enjoy seeing his list at http://www.backyardnature.net/awards/g-nc-001.htm.
You don't need to be religious to benefit from having a firm foundation for ethical living. The most eloquent, authoritative and promising of all institutions capable of informing us on ethical living is Nature.
Nature's authority for teaching us ethical living lies in this fact: As a piece of music reflects the general mood, thinking and creative method of the composer, Nature reveals the basic impulses of the Universal Creative Force. In religious terms, Nature shows us "the Will of God."
Nature is highly structured. A system of ethics can be interpreted from that structure.
For example, Nature is structured so that resources are recycled; things are not wasted. These facts amount to an ethical teaching. Nature says: It is good to recycle; it is bad to waste resources.
Nature's elaborate structure further reveals the Universal Creative Force's passion for diversity. Thus Nature teaches that humans also must cherish and hold as sacred the diverse forms and manners of being of living things.
Nature on Earth grows ever more complex as time passes. Species continually evolve toward higher, more sophisticated, more sensitive and more informed states. From that I learn that also I must constantly reassess who and what I am, and change myself to accommodate new information and new insights.
These are three of Nature's most obvious teachings. If we were to think hard we could come up with many more teachings and develop a body of "sacred literature" as impressive and much more appropriate than any gilded Bible, Koran or Torah.
However, in humanity's current early stage of evolution during which most of our behavior still is rooted in genetic programming -- matters of sex, territory and status -- embracing just the three teachings listed above make a good start.
Just these "Three Commandments" provide a sound bases for anyone who wishes to live ethically on a small, fragile Earth.
Best wishes to all Newsletter readers,