Sunday, June 9, 2013

A Diversion to the Southern Sierra Nevada Mountains: "Scorpion-ville"!

From June 3 through June 6, we spent time camping at Kennedy Meadows in Tulare County. This is an area dominated by sage and other desert-loving shrubs, and Pinyon Pines. The Kern River winds its way through the area.

Where we camped, there were extensive areas of "sand" (really finely grained decomposed granite, or DG), and I noticed many, many small holes in the sand, with a small pile of debris outside of them. After dark, a small creature could be seen at the entrance of some of the burrows, but it would withdraw out of sight when light fell on it, so the creatures and their burrows remained mysteries for a short while. Then, I was able to take a photo from some distance away, and zoom in on the creature in the entryway. It became obvious that it was a scorpion! Also, scorpions were out and about after dark in the sandy areas, especially near my black light which was attracting nice scorpion-prey.

Over a couple days I got quite a few photographs of the scorpions, in and out of their burrows.

This was the first scorpion I saw out of its burrow, near my black light. It is the California Common Scorpion, Paruroctonus silvestrii. Thanks to Kari McWest for this determination.
The same individual as above, with a small moth in range!
The typical resting position in the entryway of a burrow. This is the Swollenstinger Scorpion, Anuroctonus phaiodactylus. Thanks to Kari McWest for this determination.
Another Swollenstinger Scorpion in its burrow.
Three burrows in close proximity on a small embankment. There were easily dozens of burrows near our campsite and surely hundreds (if not thousands) in the region. There were burrows ranging from about an inch in width, to much smaller (perhaps 1/4 of an inch).
The second scorpion I saw out of its burrow. Another Swollenstinger Scorpion. These seemed by far the most common (actually I only observed one California Common Scorpion - despite its name - the one shown above!) This scorpion was sensitive and assumed a threat posture when I leaned in too close for a photo. In my experience, most scorpions do NOT get this agitated in this sort of photography situation.
The scorpion above, in threat-posture.
The same individual as above, at a different angle.
Another Swollenstinger Scorpion seen later, near the edge of the thicker woods. This one did not get agitated when I took this photo.


  1. Hi Robyn! Nice photos!
    The first one is Paruroctonus silvestrii, found from northern Baja through much of southern California and beyond to the west slopes of the Sierra Nevada, and Coast Ranges above San Francisco. It differs from Uroctonites montereus in that the latter has very pronounced granules on the dorsum of the tail (metasoma) and the last one is very pronounced/enlarged. The hands are also much more robust in Umontereus.
    The second one is Anuroctonus, either pococki (Coast Ranges into Baja) or phaiodactylus (the more eastern one, up into Nevada, Utah, Oregon, and Idaho.
    The one in the photo is a male, notice the swollen part of the stinger.
    Kari McWest

  2. Interesting that there were so many - I wonder what makes that niche so attractive to them. I kept 2 of he same sp. in one big container, and the big female ate the smaller male. So they are taking a risk living so close to each other.

  3. I would assume the soft sand for burrowing might be part of it. There were some crickets out and about -- maybe that, and other little creatures, keeps them satiated. One thing I would love to see and photograph is a female with young on her back. Must be rare as I've seen a lot of scorpions over the past years and never seen that...