I suppose it took last week's bemoaning my having seen so few snakes in this area to change things, but the fact is that not 50 feet from the Indigo Snake I ran into another species whose picture can be seen at the right.
This black, heavily speckled, very slender, three-ft- long snake was a Speckled Racer, DRYMOBIUS MARGARITIFERUS, distributed from southern Texas (listed as threatened) through Mexico and Central America into Columbia. Over much of its distribution it's known as Ranera, which means frog hunter, and it's true that its main food is frogs and toads, though it'll also eat lizards, small snakes and other small critters. It has no venom and instead of killing its prey by constriction swallows it alive.
I think the reason the racer didn't race away as once again I pulled off my backpack, retrieved my camera and waited for the camera's setup procedures to whirr and blink into place was this: True to its Ranera name, upon my approach the snake had disgorged a half-dead frog, thus making it easier to slip away if I proved threatening. Probably the snake just didn't want to abandon his meal.
After the picture was snapped he did move on, however, and so did I, hoping that by my leaving he'd return and finish his job. My experience with this species doesn't much coincide with the description on Wikipedia, which describes Speckled Racers as "fast moving, nervous snakes... "
My friend Pancho tells me that at about the same time I saw my racer, near his house in Jalpan, he saw seven Speckled Racers crossing a trail in a woodlot. There was one long one, maybe three feet in length, around which the other six stayed entangled as the long one moved. Pancho thought it was a mother with six young but it sounds to me like a female with six smaller males wanting to mate.