Prey-Handling Behaviors of Naïve Pantherophis guttatus
We studied the effects of relative prey mass and experience on prey-handling behaviors of 16 ingestively naïve Corn Snakes (Pantherophis guttatus) feeding on different categorical sizes of live House Mice (Mus musculus) over 11 feeding trials. We randomly assigned hatchlings to two categories of prey mass, relative to snake mass (small = 20–40% and large = 41–60%), and analyzed the effects of prey mass on capture position, prey-handling method, time to subdue prey, condition of prey at ingestion, direction of ingestion, and duration of ingestion. Prey mass significantly affected prey-handling behaviors. As snakes experienced larger prey, they used more complex prey-handling behaviors (hairpin loops and constriction). Snakes that had prior large-prey experience maintained constant subduing times across feeding trials, whereas snakes that had prior experience with small prey showed an increase in subduing time across trials. Snakes feeding on large prey took longer to ingest prey than snakes feeding on small prey; however, as snakes gained feeding experience, they maintained relatively constant ingestion times across trials. All snakes employed complex prey-handling behaviors prior to the point at which the prey could vigorously defend themselves, suggesting an advantage to employing complex behaviors before they are necessary. When prey reached a certain absolute size, all were constricted and killed, regardless of prior experience or relative prey size.Abstract
Frequency of prey-handling methods (represented as simple and complex methods) used by young Corn Snakes (Pantherophis guttatus) as a function of each predation trial for the small (A) and large (B) RPM categories. Beneath the first X-axis is the average absolute prey mass (g) per trial. Superimposed onto this graph is the portion of prey killed prior to ingestion (shaded area). Analyses were performed on Feeding Trials 1–11 (n = 8 per category), but the remaining data showed a strong trend toward the use of only complex behaviors and killing of all prey before ingestion.
Box-and-whisker plots showing temporal aspects of predation trials in young Corn Snakes (Pantherophis guttatus). The boxes represent the 25th and 75th quartiles, whereas the vertical lines depict the 10th and 90th deciles. The cross-bar within each box represents the median. (A) Change in the time to subdue prey over eight feeding trials for both the small (S1–S8) and large (L1–L8) categories of relative prey mass. (B) Change in the time to ingest prey over eight feeding trials for both categories of relative prey mass (labeled similarly).
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