Evolutionary Ecology

, Volume 28, Issue 1, pp 69–88

Morphological differentiation among populations of Rhinella marina (Amphibia: Anura) in western Mexico

  • Regina Vega-Trejo
  • J. Jaime Zúñiga-Vega
  • R. Brian Langerhans
Original Paper

DOI: 10.1007/s10682-013-9667-6

Cite this article as:
Vega-Trejo, R., Zúñiga-Vega, J.J. & Langerhans, R.B. Evol Ecol (2014) 28: 69. doi:10.1007/s10682-013-9667-6

Abstract

Conspecific populations inhabiting different environments may exhibit morphological differences, potentially reflecting differential local adaptation. In anuran amphibians, morphology of the pelvis and hindlimbs may often experience strong selection due to effects on locomotion. In this study, we used the cane toad Rhinella marina to test the hypothesis that populations experiencing a higher abundance of predators should suffer higher mortality rates and exhibit morphological traits associated with enhanced locomotor performance (narrower pelvis and head, longer pelvis and hindlimbs, shorter presacral vertebral column). We investigated inter-population variation in survival rate, abundance of predators, and body shape across five populations in rivers in western Mexico. We conducted (1) mark-recapture experiments to calculate survival rates, (2) linear transects with point counts to estimate abundance of predatory spiders, snakes, and birds, and (3) geometric morphometric analyses to investigate body shape variation. We found significant differences among populations in survival rates, abundance of predators, and body shape. However, these three variables were not necessarily inter-related. Increased predator abundance did not result in decreased survival rates, suggesting other causes of mortality affect these populations. While some morphological differences supported our predictions (trend for longer pelvis, shorter presacral vertebral column, and narrower head in sites with increased abundance of spiders and snakes), other aspects of morphology did not. We discuss alternative explanations for the lack of clear associations between predation, survival, and morphology.

Keywords

Geometric morphometrics Mark-recapture Survival Predation Body shape 

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Regina Vega-Trejo
    • 1
  • J. Jaime Zúñiga-Vega
    • 1
  • R. Brian Langerhans
    • 2
  1. 1.Departamento de Ecología y Recursos Naturales, Facultad de CienciasUniversidad Nacional Autónoma de MéxicoMexico D.F.Mexico
  2. 2.Department of Biological Sciences, W.M. Keck Center for Behavioral BiologyNorth Carolina State UniversityRaleighUSA

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