Temporal shift of diet in alternative cannibalistic morphs of the tiger salamander
Persistent URL
Author(s)
Denoël, Mathieu
Whiteman, Howard H.
Wissinger, Scott A.
Date Issued
January 15, 2006
Abstract
Evolutionary theory predicts that alternative trophic morphologies are adaptive because they allow a broad use of resources in heterogeneous environments. The development of a cannibal morphology is expected to result in cannibalism and high individual fitness, but conflicting results show that the situation is more complex. The goal of the present study was to increase our understanding of the ultimate benefits of a cannibalistic polyphenism by determining temporal changes in the feeding habits and biomass intake in a population of tiger salamanders (Ambystoma tigrinum nebulosum). Cannibals in this species develop a larger head than typicals and have prominent teeth, both useful for consuming large prey. Although cannibalism was only detected in cannibal morphs, large temporal variation in resource partitioning was found between morphs. The two morphs always differed in their foraging habits, but cannibalism mainly occurred immediately after the ontogenetic divergence between morphs. Cannibals shifted their foraging later to a more planktivorous diet (i.e. the primarily prey of the typical morph). Cannibals also obtained more prey biomass than typicals. These results indicate that the cannibalistic morph is advantageous over the typical development, but that these advantages vary ontogenetically. Although the results obtained are consistent with models predicting the maintenance of cannibalism polyphenism in natural populations, they show that the foraging tactics utilized by cannibal morphs, and the fitness consequences accrued by such tactics, are likely to be more complex and dynamic than previous studies have suggested.
Journal
Biological Journal of the Linnean Society
Department
Biology
Citation
Denoël, M., Whiteman, H.H., and Wissinger, S.A. (2006). Temporal shift of diet in alternative cannibalistic morphs of the tiger salamander. Biological Journal of the Linnean Society 89(2): 373-382. doi: 10.1111/j.1095-8312.2006.00681.x
Publisher
Linnean Society of London
Version of Article
Final manuscript post peer review, without publisher's formatting or copy
editing (postprint)
DOI
10.1111/j.1095-8312.2006.00681.x
ISSN
0024-4074
e1095-8339
Rights
This article was selected and published in The Biological Journal of the Linnean Society © 2006 Denoël ,Whiteman, Wissinger. All rights reserved.
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