Unusual Shots - Pretending to be Poisonous

I stepped over (literally, camouflage can be quite effective) this Bull Snake (Pituophis catenifer sayi) a subspecies of the Gopher Snake on a trail at Guadalupe Mountains National Park. In the few minutes I had to observe and photograph this specimen, and not being familiar with venomous species in that area, I made the inference that this was a pit viper. While it may be best practice in exotic terrain to assume that all snakes a venomous until confirmed otherwise, I was abnormally fooled by this individual. I found out only later this snake has the ability to flatten its head giving is the distinct appearance common to all pit vipers. Had I not assumed this reptile was poisonous, I might have tried a little harder to locate it after it slid beneath a shrub.

The effectiveness of this adaptation is quite clear. I'm sure it (the adaptation, not this particular individual) has fooled many a potential predator. If it had not, it would not have evolved through natural selection. For me though, it raises a question. As human to snake interaction increases with loss of habitat and other factors, will this unusual ability begin to be selected against. I was recently and proudly told by a family member, "If it has a neck, I kill it." She was referring, of course, to the head shape typical of pit vipers. It seems in this case that the adaptation in question might become an evolutionary disadvantage when the humans are involved.