Natural History, Evolution, and Conservation of Venomous Snakes: Four Talking Points
Greene, Harry W.
Museum of Vertebrates and Department of Ecology and Evolutionary Biology
Ithaca, New York, USA
1) The diets of snakes typically cannot be studied by direct observations, because they are secretive and feed infrequently. Instead we more often rely on palpating food from fresh caught animals, examining stomach contents of museum specimens, accumulation of anecdotes, remote photography and videography, and indirect assessment methods, e.g., stable isotope analyses. I will comment on the shortcomings, challenges, and potential for integrative assessments using diverse approaches to understanding the feeding biology of pitvipers. 2) Ontogenetic shifts from ectothermic to endothermic prey, or their lack, present an understudied aspect of venomous snake feeding biology from ecological and evolutionary perspectives, i.e., why and how do these shifts happen? I will provide examples of discrete patterns in the range of prey taken by pitvipers over the course of individual lives, and then place that variation in the context of behavioral ontogeny, phylogeny, and heterochrony. 3) Recent work has enormously increased our notions of behavioral complexity in snakes, especially social relationships, and further revelations will come from both lab and field studies. Along with other examples, I will describe a surprising field observation of repeated relocation, envenoming, and assessment of a large prey item in the context of results from experiments published by Chiszar et al. > 20 years ago—then emphasize the recent plea from Schuett et al. that we be open to surprising future discoveries, as well as pose questions that until recently would have been dismissed as irrelevant to pitvipers. 4) Conservation of venomous snakes globally will profit from increased recognition that these are indeed dangerous animals, and that primates have experienced roughly 75 million years of co-evolutionary relationships with them in that context. As also is the case with apex predators and megaherbivores, sustained coexistence with venomous snakes will require both substantially reducing the likelihood of danger to people, as well as enhancing appreciation for their positive attributes in the context of human values.