Saturday it rained hard in the morning. Kieran and I suited up in full rain gear and boots for a trip to Mount Diablo. We wanted to find out whether the millions of gallons of water that have fallen on the mountain in the last two weeks have yet trickled down through the soil and via furrows and gullies into Little Pine Creek, turning it from a dry bed into a stream singing with a thousand silver tongues again.
Those tongues were still silent, alas, though some pools had formed in the rocky, sandy stream bed. We eschewed trails, as is our habit, and followed the gully carved by the creek up through the oak and buckeye forest. As always after rain, we looked carefully for mushrooms and other fungi.
Kieran, with his sharp eyes, spotted some ancient, crumbling bones sticking out of an embankment cut by the stream. We dug the bones out and found they were the vertebrae and other bones of a deer, probably buried hundreds of years ago under sediment and only recently exposed. We got an idea of how hard it is for something to be fossilized — these bones, leached by water and eaten by bacteria, crumbled in our hands. They would never have made it to fossilization unless they were completely dissolved while still buried, and their shapes replaced by other sediment.
Rain fell steadily, the sound of an infinity of drops a sweet susurration in the forest. The oaks, both white oaks and live oaks, still had their leaves, while the buckeyes had shed all of theirs, leaving pale gray, almost violet skeletons in the forest. They’d also dropped all their huge nuts, similar to chestnuts. They fall in a leathery cover, which splits open to reveal the bright brown nut within.
Though we found about a dozen different mushrooms, we didn’t find nearly as many as we had earlier in the week in the Lakeside Garden here in Oakland.
Far up the creek in the forest, after the rain had stopped, we sat leaning against huge boulders, a kind of wild temple, and drank hot chocolate, which I’d carried in a thermos. We read a warm story, too — I read Kieran the third section of Beowulf, where the wyrm, or fire dragon, is disturbed, and the king has to fight it. All his men except Wiglaf flee into the forest, and Beowulf dies destroying the dragon.
Coming back down again, we explored the tall, mostly dead grass on the banks of the stream. Kieran shouted that he’d found a very strange praying mantis. He caught it and I walked back through the tall, wet grass to look at it. And it sure looked like a praying mantis, with raptorial front legs and big eyes. It had long clear wings with nerves in them, though, and they extended far longer than its abdomen.
We’ve both collected a lot of M. religiosa, and we knew from experience that finding an adult, winged mantis in late November is extremely unlikely. The only mantids around are the earliest batch of nymphs (we had a dozen or more hatch out in a jar on my desk just this week — we’d put in the ootheca laid by their mother beneath my father’s telescope box), which are so tiny you’d never notice them.
Turns out this curious creature is a rare mantis fly, or mantispid.
After returning to the car, we shed our damp rain gear and drove up to the high summit of the mountain, which is nearly 4,000 feet tall. Though the sun had by then broken through on the lower slopes, the summit was shrouded in dense, damp cloud, and we shivered as we crossed the parking lot to the little museum.
Every season we visit this magnificent mountain we find something completely different.
We dressed in many warm and waterproof layers. The summit of the mountain was invisible in the rain.
Little Pine Creek hadn’t yet started to flow.
We eschewed trails and hiked up the stream course itself, following the furrow up the mountain.
One of the dozen or so types of mushrooms we found.
The nut of Aesculus californica, the buckeye tree.
Serpentinite.
Another chunk of green serpentinite, our state rock.
Fungus and moss growing on a fallen tree.
Kieran found several sets of Turritella fossils.
Fossils of marine shells.
Turritella fossils from the Eocene.
We drank hot chocolate and read Beowulf in the forest.
Red cone galls.
A fallen white oak leaf shows what passes for autumn colors out here.
Tiny red cone galls on a white oak leaf. They’re formed by a tiny wasp, Andricus kingi.
Some trees had more than one type of gall on them — here’s an enormous oak apple gall, made by the wasp Andricus quercuscalifornicus, and several leaves with tiny galls.
People have been partying up on Mt. Diablo for decades — here’s an ancient beer can with a pull tab.
And here’s the tab. How long ago, and how far up the mountain, was this tab pulled? The rain’s had decades to wash it down.
Kieran spotted this curious creature, a Mantispid, in the tall grass.
Mantispids look like a praying mantis, but they’re Neuroptera, or nerve-winged insects.
The museum is built right on the crown of the mountain.
Kieran warmed up by reading a book about tarantulas in the museum.
Steven E. F. Brown 