Snake Feeding Strategies and Adaptations—Conclusion and Prognosis

Abstract

Today's symposium has provided elegant demonstrations that being slender may have advantages to snakes; the advantage of slenderness should be easily recognizable to middle-aged members of the audience and to most of us during the post holiday season. In snakes, slenderness allows traverse of crevices off the ground and below the ground; slender snakes can extend their trunk across unstable branches and bridge discontinuous portions of their environment. The adaptations of snakes represent the current state of a process that was already underway in the Cretaceous. Clearly, the process of slenderization did not proceed under constant conditions, for not only did the physical environment shift, but their predators and prey evolved possibly at an accelerated rate due to the success of snake specializations. It is obvious also that the adaptive process affected many aspects of snakes; slenderization involved a profound reorganization. Some aspects may have been abandoned or others appear to have been reformed along the way; it is unlikely that such aspects conferred much advan? tage at the time of loss. The relative advan? tage of some of these aspects may later have increased under different circumstances. Thus, we observe the reversal of trends, for instance the increased stoutness of some Recent species of vipers (Pough and Groves) and the shift from concentration on large prey to feeding on many small items (Greene). Such cases make it likely that the history of snakes includes multiple reversals of trends and development of analogous substitutes. The sequences we dimly dis