Amphibian

This afternoon I was walking in Purissima Creek Redwoods Open Space Preserve, through Douglas Fir woodlands, along a ridge that was about 1,400 feet aboe sea level. I happened to look down at my feet, and there was a — well, no, it wasn’t a lizard, it was some kind of salamander.

Sometimes it pays to walk slowly and deliberately. I got down on my knees to look more closely.

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I haven’t seen seen a salamander since I moved to California more than five years ago, so I stopped to watch it for a while. I placed a quarter on the ground, to give a sense of scale in the photos I was taking. The salamander obligingly stepped right on the quarter:

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It was fun to watch it walk — it had that rolling, deliberate salamander gait, so very different from the quicker-than-the-eye sprinting done by lizards. Eventually, it walked off the trail and disappeared into the leaf litter.

When I got home, I looked on the California Herps online identification guide. I’m pretty sure it was a Rough-skinned Newt (Taricha granulosa). Another possibility would be the Red-bellied Newt (Taricha rivularis) — but the eye of my newt showed some whitish yellow, while T. Rivularis has uniformly dark eyes.

Invertebrate pitfall trap

When we humans think about the interdependent web of life, we tend to think about the relationships between ourselves and familiar organisms like mammals and trees. These are organisms that are either larger than us or relatively close to us in size, or they are taxonomically close to us. But if you conduct a survey of biodiversity in a given tract of land, the majority of non-microscopic species you find will be invertebrates, e.g., insects, spiders, crustaceans, etc. For a more realistic theological understanding of the web of life, I think it’s necessary to develop a more realistic understanding of biodiversity. It is easy and fun to feel a connection through the web of life to relatively cute organisms like rabbits, and to relatively majestic organisms like redwoods. Understanding our connections with organisms that are not particularly cute or majestic expands our idea of the interdependent web of life.

A few years ago, I participated in a blogger’s bioblitz; a bioblitz is a study that provides a “snapshot of biodiversity.” One of the tools used in a bioblitz is an insect pitfall trap; this kind of trap provides a sampling of insects and other invertebrates. I decided to place an insect pitfall trap in our front yard, so I could see some of the invertebrates that live in our urban setting.

Some online research revealed that pitfall traps made of glass are most effective (Oecologia 9. VI. 1975, Volume 19, Issue 4, pp 345-357), but the easiest way to make a pitfall trap is with nested plastic drinking cups. You dig a hole deep enough to bury the two nested cups, and pack dirt around them so that the rim of the upper cup is exactly at ground level. Then you can remove the upper cup, dump out all the dirt that fell into it when you were burying it, and then replace it. I used two nested 10-ounce clear plastic drink cups:

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To use pitfall traps ethically, you should check them at least once a day, and either release the captured organisms or collect them responsibly. If you’re expecting rain or hot sun, you should place some sort of cover over the trap, raised up an inch or two. The cover will keep rain and sun out, but still allow invertebrates to crawl into the trap. If you’re no longer going to use the trap, pull it out of the ground.

Here’s what I found in my pitfall trap this afternoon:

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The large organism appears to be in the genus Stenopelmatus; from looking at online identification guides, I’d guess this organism is probably a Dark Jerusalem Cricket (Stenopelmatus fuscus [Haldeman, 1852]). Where does it fit into the web of life? According to the Nevada at Reno Department of Extension: “Because it is nocturnal and comes out of the ground at night to roam around, owls, including the endangered spotted owl, feed on it. Probably other nighttime predators such as coyotes, foxes, and badgers eat it as well.” As for their food sources, the Orange County (Calif.) Vector Control District (OCVCD) says the primary food sources of Jerusalem Crickets are “plant roots and tubers; however, “they also feed on other insects, even their own kind.” The OCVCD also states that Jerusalem Crickets do not pose a health threat to humans.

The other organisms in the trap — you can see something like a centipede under the Jerusalem Cricket’s left antenna — were too small for me to have any hope of identifying. Besides, if I’m going to accurately identify insects and similar invertebrates, I’d need to ask an entomologist equipped with powerful binocular microscope.

More about insect pitfall traps.

Ferguson, six months on

Six months ago today, Michael Brown was shot and killed by a police officer in Ferguson, Missouri. I did not then, and do not now, find this shooting to be astonishing. Brown’s killing was preceded by other, similar, well-publicized events. Most notably, in 2009, Oscar Grant, another young black man, was shot and killed by a police officer. And in 2012, Trayvon Martin was shot and killed by by a neighborhood watch coordinator. And on August 5, 2014, John Crawford III was shot and killed by police officers in a Walmart store. In the bare fact of Brown’s killing, there wasn’t much to astonish.

This kind of violence has been going on for a long time. W.E.B. DuBois, in his book Black Reconstruction in America, 1860-1880, wrote about the “widespread violence in the South, the murder and mobs,” that occurred during Reconstruction:

“Probably in no country in the civilized world did human life become so cheap. This condition prevails among both white and black and characterizes the South even to our day. A spirit of lawlessness became widespread. White people became a law unto themselves, and black men, so far as their aggressions were confined to their own people, need not fear the intervention of white police. Practically all men went armed and the South reached the extraordinary distinction of being the only modern civilized country where human beings were publicly burned alive.” [p. 700]

The violence described by W.E.B. DuBois no longer exists in quite that form, but it counts as its direct lineal descendant the violence that killed Oscar Grant, Michael Brown, and many others. While such violence might surprise us, it has lost its power to astonish.

But there were things about Brown’s killing that did astonish me. The initial response of police and elected officials to the protests which followed Browns’ killing was astonishingly tone-deaf — it was almost as if police and elected officials were trying to say things that would inflame tensions. The grand jury investigation was similarly tone-deaf — I sometimes felt was as if the district attorney’s office did everything they could to erode my trust.

Further, I was astonished how many non-black people actually paid attention to Michael Brown’s killing. Whether they reviled him for stealing cigarillos, or lauded him for being a hero, it seemed to me that more non-black people noticed Brown’s death than noticed the death of, say, Oscar Grant or John Crawford. White people in particular seemed to pay close attention. What drew the attention of so many of us white people? Was it the militarized police response to the protests in Ferguson that drew white people’s attention? — with some whites fearing that such militarized tactics could well be used on them, and other whites feeling safer because the police had so much military gear with which to quash protests? I don’t know. I only wish more white people could express a more nuanced view of Michael Brown, making him out to be neither a one-dimensional saint, nor a one-dimensional sinner, but rather a complex human being living in a difficult and complex world.

And I admit I was sometimes astonished by the way some whites responded to Brown’s killing. I remember seeing a video of one of the Ferguson protests where someone who appeared to be white harangued a black police officer, telling the officer that he should get rid of his uniform and join the protesters. This seemed to be another response lacking awareness of the nuances and complexity of the issue at hand.

But it is not easy for us white people to talk about race so openly. White people rarely talk about race with other white people. I can tell you this from experience:— if you’re a white person and you want to end a conversation with another white person, bring up the topic of race: as often as not, the other white person will find an excuse to end the conversation; sometimes they just walk away from you, which can feel a little strange.

If the Ferguson protests do prompt conversations about race among us white people, I will consider that a positive result. Here is W.E.B. DuBois again, from the same book, a few pragraphs after the quotation given above: “The theory of race was supplemented by a carefully planned and slowly evolved method, which drove such a wedge between the white and black workers that there probably are not today in the world two groups of workers with practically identical interests who hate and fear each other so deeply and persistently and who are kept so far apart that neither sees anything of common interest.” If the Ferguson protests provoke a wide conversation about the importance of black lives, that would be an even better result.

Those wedges DuBois talks about are driven between other racial groups in the United States as well. Somehow we have to extract those wedges that have been driven between all the races in the United States.

Snowstorm

I’m in Massachusetts visiting my dad. It’s snowing. And snowing. And snowing. It’s been snowing for two days now. They had something like three feet of snow when I got here, and it looks like this storm is going to dump another foot or foot and a half of snow. Here’s the view from my motel window:

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That road behind the buildings? That’s the interchange of Route 110 and Interstate 495. At this time of day, you’d expect lots of cars. But everything is closed due to snow, so as you can see there is hardly any traffic out there. And the parking lot for the restaurant next door is basically empty.

I just wish they could send some of this snow to the Sierra Nevada mountains in California, where it is desperately needed.

No one sings in church any more

On the Sacred Harp Friends page on Facebook, Katie posted a link to a blog post by Thom Schulz, titled “Why They Don’t Sing on Sunday Anymore.” Schulz’s reasons why people don’t sing in church: too often services are spectator events; church music is dominated by professionals, to the point of squeezing us amateurs out; sometimes the volume gets cranked up so high people just stop singing; the hymns are unfamiliar or hard to sing.

Katie then noted that Sacred Harp singers do sing, and we sing fervently — because there are no spectators, there are no professionals, it’s loud but not deafening, and Sacred harp singers have been singing pretty much the same tunes for a century and a half.

Actually, in my church people do sing. Amy, the senior minister, and I made a pact some years ago that the first hymn would mostly get chosen from a pool of ten or so hymns; that way, the kids can memorize ten or so hymns and know them by heart. And indeed the kids (and the adults) do memorize those hymns, and they do sing with fervor and gusto. In one recent service, I watched as one of our more cynical upper elementary kids stood on a chair, hung on to dad, and sang with utter abandon; cynicism gone, this child was completely lost in the hymn.

Given my experience, I’m with Thom Schulz: congregational singing does not need spectators, over-professionalism, blare, or crappy songs. Congregational singing can aim towards joy, towards ecstatic union with the universe through song. Congregational singing can be — should be — cynical kids belting out a favorite hymn at the tops of their voices, completely lost in the moment.

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Concrete block rocket stove

This past Sunday, the middle school ecojustice Sunday school class cooked on rocket stoves. We based our stoves on design principles developed by Dr. Larry Winiarski, who is affiliated with the Aprovecho Research Center. A rocket stove makes more efficient use of biomass fuels (wood, twigs) through more complete combustion; this also results in fewer harmful emissions. According to the Aprovecho Research Center:

“Improved cooking stoves address at least 5 of the 8 United Nations’ Millennium Development Goals: [1] ending poverty and hunger; [2] gender equity; [3] child health; [4] maternal health; and [5] environmental sustainability.”

So while we don’t really need rocket stoves here in the Bay area (except perhaps in disaster situations), learning about and building them is a great introduction to using appropriate technology to meet ecojustice goals of human well being and environmental sustainability.

If you’re not familiar with rocket stove design principles,Aprovecho Research Center has an excellent introduction on this Web page. Scroll down and click on document no. 8, “Design Principles for Wood Burning Cook Stoves,” June, 2005.

Enough background. Here are instructions for building a concrete block rocket stove, followed by photos of our rocket stove in action:

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Click the image above for a drawing of how to build our concrete block rocket stove. You will find other plans for a concrete block rocket stove on the Web, but those plans typically require a concrete h-block, an oddball type of block that we were unable to find. However, most bit home improvement stores carry 8 x 2 x 16 inch concrete cap blocks, and 4 x 2 x 8 inch concrete brick — two cap blocks and two concrete brick can be arranged in an “H” shape to make a stove. In fact, this is a better solution than a concrete H-block, because you can adjust the concrete brick such that you have a constant cross-sectional area throughout the L-shaped combustion chamber (see “Design Principles for Wood Burning Cook Stoves,” principle 7).

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Above: The concrete block rocket stove after use. We placed two concrete bricks on the top on which to place cooking implements, etc. The bottom concrete block serves as a convenient place to store fire wood. Notice that our firewood is all salvaged building materials and wood pallets, split to appropriate size for burning.

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Above: Cooking on the stove. “Design Principles for Wood Burning Cook Stoves” states that a combustion chamber with a 12 x 12 cm cross sectional area is “usually sufficient for a family sized cooking stove.” Our concrete block rocket stove has a cross sectional area of 12.5 x 15 cm. It put out a good amount of heat for cooking scrambled eggs for half a dozen people. Note that one person is feeding the fuel into the stove, while the other cooks — we found it was challenging to cook and tend the fire at the same time.

We did not try to boil water on our concrete block rocket stove, to see how long that would take. Maybe that’s a task for a future class.

Update, one year on: This has proved to be a good, but not excellent, rocket stove design. The chief problem with this design is that the concrete block acts as a fairly large thermal mass, and it takes a while to heat the block. Once the block is warm, the stove functions pretty efficiently; while the block is still cook, it’s not as good. Another problem is that the stove is finicky, and requires constant attention to feeding fuel in order to maintain a fairly constant temperature. Nevertheless, given the low cost of materials, and the ease of construction, this remains a practical design.

Mammal signs

Yesterday, Carol noticed some scat and other mammal signs in our garden. First, something has been eating the tree kale Carol has been growing. The bitten-off leaves and stems are some 425 mm / 17 inches from the ground:

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This seems a little high off the ground for rabbits. According Jameson and Peeters Mammals of California, the rabbit most likely to be found in our area is Audubon’s Cottontail (Sylvilagus audubonii). The total length, from nose to tail, of Audubon’s Cottontail is 370-400 mm, or about 15 inches; it would be a stretch (but possible) for a rabbit that size to reach up 425 mm to nibble on stems and leaves.

Right next to the tree kale is a deposit of scat: many small pellets, all about 5-7 mm in diameter. This, according to Olas Murie in A Field Guide to Animal Tracks would be absolutely typical of cottontails. But it may be coincidence that there’s a deposit of cottontail scat right next to the bitten-off twigs, and it could be that a deer got into our yard; Carol has seen deer down the cul-de-sac on which we live, and we suspect that they move up and down San Mateo Creek, which is less than a block from our house.

There’s another scat right next to another of our garden beds. Here’s my sketch of it:

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The lack of taper on the ends, and the relatively large size, leads me to believe that these are raccoon scat. Murie says that raccoon scat can be difficult to identify, and “may be confused with the larger skunks and opossum.” But given the size — on the large size for raccoons, probably too big for skunks or opossums — and the fact that we regularly see raccoons at night in our garden, I’m going to guess this is from a raccoon.

Sacred Harp Convention

Once every three years, the All-California Sacred Harp Convention comes to the Bay area. It’s going on this weekend.

What is Sacred Harp, you ask? It has nothing to do with harps, but you sing from a book called The Sacred Harp. At a Sacred Harp convention, you sing for three hours in four-part harmony at the top of your lungs along with 150 other singers who range in age from 8 to 80-something. Then you break for this fabulous potluck lunch, where you eat more good food than you can believe. Then you go back sing again for another three hours in the afternoon. Then you go back the next day and do it all over again.

16 brick rocket stove

In our middle school ecojustice class, one of the things we’re doing is experimenting with alternative low-cost, low-impact cooking methods, such as a solar oven made out of cardboard. Now we’re experimenting with rocket stoves, designed originally by Dr. Larry Winiarski and colleagues at the Aprovecho Research Center. Rocket stoves use biomass to cook, but are much more efficient than traditional cooking fires, and because they’re more efficient produce fewer pollutants such as smoke and harmful gasses. Not really something we need in the first world, except in disaster situations, but a huge advance for the developing world.

Last week in class, we put together a simple brick rocket stove but couldn’t get it to light. So I spent some time this week building and using a simple rocket stove made of 16 bricks. This stove is based on Larry Winiarski’s 16 brick stove, but instead of using adobe bricks I used clay bricks commonly available at masonry supply houses and building supply centers. Specifically, I used nominal fifteen 8 x 2-1/4 x 4 inch clay bricks, and one 8 x 1 x 4 inch clay brick, as shown in the sketch below:

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For fuel, I split an 18 inch long 2 x 10 into finger-sized pieces. To light the stove, I balled up a piece of paper and dropped it down the center hole, dropped some shavings, small scraps of wood, and slightly larger scraps of wood on top, then dropped a lighted match in. When the fire was burning well, I began feeding 3 to 4 pieces of fuel in from the bottom, adjusting the air intake gap as needed to get a hot flame.

The rocket stove needs you to pay attention to it. The fuel burns pretty quickly, and you have to keep pushing it into the combustion chamber, adding new fuel as needed. Once the fire was going strong — which took seven or eight minutes — I got ready to cook.

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Continue reading “16 brick rocket stove”

Medusa

I’m writing lesson plans and teacher resources for a curriculum for upper elementary grades on Greek myths. The core material in the curriculum was developed with Tessa Swartz, a middle school student who had taken classes with me where I piloted some of the preliminary material. Tessa proved to be a valuable collaborator, especially given her sensitivity to the essentially alien nature of Greek myths, and her willingness to go beyond the common trite interpretations of many of these myths. As we developed the core material of the curriculum, both of us got interested in the figure of Medusa. Here’s an excerpt from this new curriculum, a teacher resource on Medusa:

Medusa as imagined by the artist CarvaggioWhen we chose stories for this course, both of us placed the Medusa story at the top of our lists. What makes Medusa such a fascinating figure? The face of Medusa contains great power: the power to freeze others into stone. On the other hand, we considered Medusa’s killer, Perseus, to be little better than a bully, a strong-arm man who coerces others into doing what he wants through violence or the threat of violence. So the story of Medusa can lead to interesting explorations of power, and the use of power.

Let’s look at Medusa first: Continue reading “Medusa”