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Ecological separation in a polymorphic terrestrial salamander
Carl D Anthony1, Matthew D Venesky, Cari-Ann M Hickerson
1Department of Biology, John Carroll University, University Heights, OH 44118, USA. canthony@jcu.edu
The Journal of Animal Ecology
|May 16, 2008
Summary
Red-backed salamanders show distinct diets and mating preferences between striped and unstriped morphs. While some ecological separation exists, assortative mating suggests limited divergence in this polymorphic species.
Area of Science:
- Ecology
- Evolutionary Biology
- Herpetology
Background:
- Speciation research often focuses on reproductive isolation in recently diverged populations.
- Polymorphic species offer insights into reproductive isolation during divergence.
- Plethodon cinereus (red-backed salamander) color morphs have been linked to climate, but diet and mate choice differences remain unexplored.
Purpose of the Study:
- To investigate sympatric ecological separation and reproductive isolation between color morphs of Plethodon cinereus.
- To determine if diet, mate choice, and surface activity differ between striped and unstriped red-backed salamanders.
Main Methods:
- A 2-year field study in north-eastern Ohio utilizing artificial cover objects.
- Assessment of salamander diet composition and prey profitability.
- Analysis of mating preferences and surface activity patterns in relation to color morph.
Main Results:
- Significant differences in diet were observed between striped and unstriped morphs, with striped individuals consuming more diverse and profitable prey.
- Assortative mating was detected, with opposite-sex pairs consisting of the same color morph.
- Striped males were more frequently found with larger females compared to unstriped males.
- Unstriped morphs exhibited earlier withdrawal from the forest floor in response to falling temperatures, supporting adaptation to warmer conditions.
Conclusions:
- The two color morphs of Plethodon cinereus display partial ecological separation and a tendency for assortative mating.
- Despite these differences, the frequency of intermorph pairings suggests that the populations are unlikely to be undergoing significant divergence at this time.
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