Rosy Boa: Victim of heat and drought

"That not expected is that which is remembered."

This is what my father would say in one of his occasional profound moments.

He repeated it whenever he heard or saw something unusual, no matter how trivial the event.

Perhaps that is why this naturalist remembered the evening of January 25. Something happened that I had never before experienced.

It had been an unseasonably warm and wonderful day in the Coachella Valley. Some cities experienced a high temperature of 82 degrees Fahrenheit, in spite of, it being the dead of winter. I was returning home in the early evening, and about to turn onto my street, when I saw an animal in the headlight beams.

It was a snake, a Rosy Boa to be exact. In my entire life I have seen less than a handful of snakes crawling about in January. Never had I seen a snake out and about at night in January. Winter nights are simply too cold for any cold-blooded (technically poikilothermic) animal to be active.

But there was the snake, crossing the road in front of my vehicle. I checked the air temperature gauge on my dashboard. It read 69 degrees Fahrenheit. I drove into my driveway (just a hundred feet or so from where I found the snake), put the car in my garage and checked the thermometer on an exterior wall of my home. That thermometer, too, read 69 degrees.

Over the years I have found a variety of snake species active on nights when the temperature was 65 degrees and above. But this was in early spring when daytime temperatures regularly reach into the high 80s; not in January. I checked the daily temperatures on the days before January 25. It had been a warm January with daytime maximums regularly in the high 70s and at least one day exceeding 80 degrees. Had my Rosy Boa thought it was spring?

There was also something strange about the snake. As a species, the Rosy Boa (Lichanura trivirgata) is heavy bodied for a serpent. This is true of most members of the Boa Family including the huge Boa Constrictor of Mexico and South America. My Rosy Boa, however, was rather slender. In fact, I had never seen a Rosy Boa so slender. I assumed it was a very hungry snake. Had it emerged early from hibernation in hopes of finding food? The small rodents that were once extremely common around my home have nearly disappeared. Presumably this is because we are now in the fourth year of a serious, verging on catastrophic, drought. Little or no rain translates into a paucity of seed production. Poor seed production means few nutrients for rodents and possibly reproductive failure as well. In the end, this means little or no food for my Rosy Boa.

So that day, I picked up the Rosy Boa and moved it off the road so that it would not be run over by the next vehicle. The snake, however, appeared destined for a slow death by starvation. In its apparent weakened condition its chances of finding and securing food were probably lower than ever. Perhaps it would have been more humane to have left it on the road.

Cornett is a desert ecologist and author of Desert Snakes.