Tag Archives: shakerag

Log walkers

I’ve had an infrared-triggered camera set up in Shakerag Hollow for the last few months. The camera takes photos of animals as they climb along or walk around the fallen ash tree. The camera takes color pictures during the day, then at night uses an infrared flash that is invisible to animals.

The huge log is quite a highway. Squirrels are by far the most abundant creatures, but others also make appearances.

 

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Oligyra orbiculata

This little snail is an evolutionary oddity, a fish out of water. I found this particular individual clinging to a tree in the upper reaches of Shakerag Hollow. The common name is “globular drop,” quite appropriate given its pea-sized shell and rotund shape. The shell is very thick and feels like a pebble.

oligyra treeUnlike all other land snails and slugs in our region, this species belongs to the family Helicinidae, a group of mostly tropical land snails that are more closely related to the marine snails than they are to other terrestrial snails. The animal’s body reveals this kinship: it has an operculum (a “trap door”) with which it seals its shell when withdrawn, it has just one pair of antennae (other land snails have two pairs), and its eyes are located at the base of the tentacles instead of at their tips. These seemingly minor differences indicate a deep divergence, analogous perhaps to the difference between a bird and a bat. Like birds and bats, the two lineages of snails independently evolved the ability to live in a new habitat — creeping onto land. Not quite as impressive as taking wing, but then what use is a radula in the air?

The following photographs are from another individual, one that lived in the limestone at the bottom of the mountain.

Oligyra orbiculata with operculum protecting the shell aperture.

Oligyra orbiculata with operculum protecting the shell aperture.

One pair of tentacles...

One pair of tentacles…

An entomological Milesian tale

Milesia virginiensisMilesia virginiensis2The common name for this wasp-mimicking fly is “news bee” or, more optimistically, “good news bee.” The moniker was given to the insect for its habit of zipping through the air toward a human then holding steady, imparting the news in a loud buzz. Once the news has been sung, the fly flings itself away to find another willing ear.

This habit might also account for the generic name of the species, Milesia (this one is Milesia virginiensis, I believe). Milesian tales are lurid, captivating short fables, named for Aristides of Miletus, “a writer of shameless and amusing tales with some salacious content and unexpected plot twists” (or so says that rock of classical knowledge, Wikipedia). A fly’s version of a Milesian tale would be fun to hear, but regrettably I could not translate the buzz that I heard in Shakerag Hollow and so missed this Dipteran’s narrative complications and witty innuendo. Maybe you can do better: my recording of the insect follows. The fly was perched on a leaf, washing its forelegs. Suddenly it launched itself and flew to me to give The News. Once done, the fly darted away to gossip at a fallen tree, then shot out of earshot.

(Web browsers differ in how they handle sound files, so I have uploaded two files: the first is mp3 and the second is m4a. You’ll either see a “play” button, an option to download, or both. The background sounds are cicadas and a Carolina wren.)

Rattlesnake

I’d been sitting on the dead ash log for a good thirty minutes before I noticed that I had company. The rattle caught my eye — what an odd piece of vegetation — then the whole snake popped into consciousness — whoa! The animal was curled catlike, its nose and tail resting on the body. It did not move one tiny little bit for the hour that I watched.

2013-06-20 rattlesnake ash 003The eye is clouded which, I think, means that the snake is preparing to molt.

2013-06-20 rattlesnake ash 016A close-up of the scales on the animal’s back (taken with a flash, hence the change in tone from the photos above):

2013-06-20 rattlesnake ash 020The camouflage was incredible: the head was a perfect match for sun-bleached maple leaves, the dark patches were the color of wet litter. Hard to spot, even when you’re close:

2013-06-20 rattlesnake ash 008

I returned the next day found the snake coiled in exactly the same place, its body shifted slightly. Still very hard to see:

spottherattlesnake2By coincidence, I received a frozen road-killed rattlesnake this week from some colleagues whose vehicle accidentally violated the revolutionary imperative: Don’t Tread on Me. This allows a closer look at the source of the phobias that have etched snakes into the deepest parts of our subconscious (religious allegories, anyone?).

roadkilledrattlesnakeIn pulling open the mouth to get a photo, I managed to spike myself on the lower teeth. So when asked whether I’ve ever been bitten by a snake, I can now answer No, but I’ve bitten myself with a rattlesnake. Another entry in the Annals of Zoological Stupidity. As it happens, this week I’m reading David Quammen’s excellent new book, Spillover, which is full of tales of microbes leaping into humans through pin-prick wounds. So far, the end of my thumb shows no sign of incubating the next zoonotic pandemic.

If these images fang you with fear, let me add that I’ve spent thousands of hours in Shakerag Hollow and this is the only close encounter I’ve had with a rattlesnake.

The timber rattlesnake is declining across most of its range due to habitat changes, road mortality and direct persecution from people. In its former territory in the Northeast, sightings are very rare indeed. In the snakes’ place, plagues of tick-bearing small rodents tromp merrily through the woods, their enemy defeated.