Abstract

In this study, we explored chemosensory, ingestive and prey-catching responses of neonate Mexican Black-bellied Gartersnakes (Thamnophis melanogaster) to crayfish (Cambarellus montezumae). By comparing snakes from a recently discovered crayfish-eating population and a typical non-crayfish-eating population, we asked which behavioral components change as a species enlarges its feeding niche. In the crayfish-eating population chemosensory responsiveness to crayfish was not enhanced but its heritability was higher. Neonates of both populations showed similar preference for freshly-molted versus unmolted crayfish, and whereas the tendency to ingest both crayfish stages remained stable between ages 15 and 90 days in the non-crayfish-eating population, in the crayfish-eating population it actually decreased. Techniques to catch and manipulate molted crayfish were similar in the two populations. We discuss the possibility that there is no increase in the behavioral response to eat crayfish by the neonates of the crayfish-eating populations, possibly due to the absence of ecological and spatial isolation between the two T. melanogaster populations. The crayfish ingestion in some population of T. melanogaster can be explained by environmental differences between populations, or by recent origin of crayfish ingestion in T. melanogaster.

Highlights

  • Intraspecific geographic differences in snake diets have been associated with behavioral microevolution within species, and geographical variation in selection on feeding (Arnold, 1992; De Queiroz, Henke & Smith, 2001; Tuttle & Gregory, 2009)

  • The relative response for control was similar between C (0.14 ± 0.54) and non crayfish-eating (NC) neonates (0.21 ± 0.25; Student-t 47 = 0.53, P = 0.70; Fig. 1B)

  • Our study suggests that T. melanogaster are born with an innate chemosensory and ingestion interest in both freshly-molted and unmolted crayfish, because are both recognized as prey and readily attacked

Read more

Summary

Introduction

Intraspecific geographic differences in snake diets have been associated with behavioral microevolution within species, and geographical variation in selection on feeding (Arnold, 1992; De Queiroz, Henke & Smith, 2001; Tuttle & Gregory, 2009). Congenital, chemically based preferences for different prey taxa have been widely demonstrated in several Thamnophis species (Burghardt, 1970; Burghardt, 1975; Burghardt, 1992). Adaptive plasticity was documented when the chemically based congenital preference of Mexican black-bellied garter snakes for a dangerous species of. How to cite this article Manjarrez J, Macías Garcia C, Drummond H. Congenital feeding response to a novel prey in a Mexican gartersnake.

Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call