One of my sons keeps pet snakes. When he was younger, I had some contact with the snakes and was struck by the degree to which they seem to have distinct personalities: calm, friendly, bad-tempered, curious, etc. Given what I knew about the mental equipment of snakes, it seemed a bit dubious to me that they would really have different personalities, so I wondered if maybe we were just misinterpreting their behavior or reading too much into it.
Recently I’ve been observing bird personalities. The wonderful nest cam run by the Santa Cruz Predatory Bird Research Group shows—well, I was going to say a bird’s-eye view—anyway it gives fantastic close-up coverage of three peregrine falcon chicks (eyases). The birds hatched just over a month ago in a nest box on top of San Jose City Hall and are being fed and cared for by their parents, a pair of falcons named Jose and Clara. I’ve been fascinated by seeing the babies grow and change over the past couple of weeks, and it seems to me like maybe I can observe the ways that they’re growing into distinct individuals, although it’s hard saying because I can’t always tell them apart. This is not my first exposure to bird personalities. My brother Vinny cares for a varying group of parrots, and from his stories I can see that the birds are obviously distinct individuals. Also Mark Bittner (The Wild Parrots of Telegraph Hill: A Love Story . . . with Wings) described the parrots he befriended as having different personalities. And certainly other types of animals (horses, dogs, cats) have particular temperaments.
But still I was surprised to see that, according to this article from Science Daily, personalities have been observed in more than 60 different species, including some insects. Maybe I was not off the mark in seeing personalities in those snakes after all. Even more interesting, an international group of researchers has come up with the beginnings of an explanation for why different personalities develop within a species. The group modeled animal behavior as it relates to a fundamental decision: stick your neck out and risk death, but reproduce earlier, or hunker down safely and wait for more favorable conditions (which trades the risk of early death for the risk of never reproducing).
Animals face this kind of tough choice in a variety of contexts, and have to respond to it somehow. The researchers’ model looks at several behavioral traits related to being risk averse or risk prone, and it shows that over time a population will evolve to contain individuals with distinct personalities based on these characteristics.
I have a collection of about 20 small arboreal pythons, and the personality differences among them can be striking. For captive animals, what’s interesting is how much the cage environment influences this. Snakes are typically kept in very simple “laboratory-style” cages with paper substrate, a hide box, and a water bowl – that’s it. I recently switched all my cages to much larger, more complex vivarium-style cages that to some extent mimic the snake’s natural environment: plants, moss substrate, bark, leaves, branches, etc. The richer environment allows a richer expression of behavior, and the personalities are expressed that way as well. You can see a wider range of behavior that highlights the personality differences that might not be expressed in traditional caging environments.
I haven’t read the article cites, but I always figured that, since much of human emotion comes from our “reptile brain”, the emotional life of snakes is richer than we imagine. They show anger, fear, pleasure, pain, satisfaction, shyness, curiosity, territoriality, protectiveness, competitiveness, lust…while they don’t have the conscious awareness we do of these emotions (“wow I was really pissed off”) they still feel the intensity of them. I think many people go overboard in rejecting snake emotions as anthropomorphizing…maybe remnants of the Cartesian soul-less machine metaphor?