Tuesday, October 9, 2012
I'm always cautious about thinking I can identify an individual animal, especially where reptiles or amphibians are concerned. In the absence of some clearly unique characteristic – often the result of an injury – two snakes or frogs of the same species and the same age will generally look the same. It's especially hard to tell them apart when they're young, before they've had time to accumulate scars or other differences that come with variations in diet and experience.
But when I revisit a location and find a snake of the same rare species and the same size, in exactly the same spot on the same log – I'm pretty confident in saying I've found the same snake. In this case it happened on Mount Diablo, where an Alameda whipsnake was hunting for lizards on a fallen tree.
Whipsnakes can move with impressive speed when they need to, but rely on stealth and patience to catch their prey. When dealing with a potential predator – or a pesky photographer – a whipsnake will use whichever tactic fits the situation. This one demonstrated the advantages of moving slowly.
As I approached for a photo, I only had a partial view of the snake, without a head or tail to tell me which way it might be going. The lateral stripes and slender build gave me no visual cues, so I couldn't even be sure it was moving – until the tail passed by, at which point the snake just seemed to get thinner until it disappeared. A minute later, it reappeared about twelve feet away, at the other end of the log. I approached again and saw the same disappearing act, followed by another reappearance in the original spot.
A week later I was back at the same log – and the snake was still there, right where I had left it.