Using animal tracks to decipher the foraging mode of species capable of altering between the sit-and-wait and widely foraging modes: a case study of the sand viper Cerastes vipera

Abstract

Abstract The sand viper Cerastes vipera can employ one of two distinct foraging modes, the widely foraging or sit-and-wait mode, depending on the interplay between external and internal factors. Here, I illustrate how tracking methods can be used to evaluate the relative usage of each of the two foraging modes by the sand viper. Foraging theory models generally refer to the time invested in foraging as the main indicator of the energy invested in foraging. I suggest that tracking and counting print marks on trails offer a more precise method of estimating foraging costs in the field. I model the benefits and costs of the viper employing each of the two foraging modes using tracking data, and discuss how it can be used to decipher its foraging mode. I present a measurement approach by which to assess the relative usage of different foraging modes. I contend that the proposed tracking methods and their analysis should prove to be equally applicable to other animals that leave print marks on sand or snow.