When aposematism is not enough: Exotic Rattus rattus shows no mercy for carcasses of Salamandra salamandra in insular populations

Abstract Predator–prey interaction is a major force driving natural selection. Yet, the identification of species preying on, or consuming, aposematic species is largely unknown. Here, I conduct a study evaluating the role of the exotic Rattus rattus as a consumer and possible predator of the aposem...

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Bibliographic Details
Published in:Ecology and Evolution
Main Author: Velo‐Antón, Guillermo
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2024
Subjects:
Online Access:http://dx.doi.org/10.1002/ece3.11229
https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.11229
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Summary:Abstract Predator–prey interaction is a major force driving natural selection. Yet, the identification of species preying on, or consuming, aposematic species is largely unknown. Here, I conduct a study evaluating the role of the exotic Rattus rattus as a consumer and possible predator of the aposematic and toxic Salamandra salamandra . I used camera traps to investigate the response of R. rattus towards S. salamandra carcasses in two insular populations, Ons and San Martiño (NW Spain), which show remarkable contrasting behaviour (nocturnal vs. diurnal activity) and demographic and phenotypic differences. This study unveils R. rattus consumes S. salamandra despite its aposematic colour pattern and toxicity. The high number of salamander carcasses consumed or taken by rats throughout each island (90%–100%) and the lack of other possible predator–prey interactions points to R. rattus as an efficient consumer of S. salamandra in these insular environments, which might exert a high predation pressure on both islands. Yet, the drivers underlying the behavioural and phenotypic differences in these insular populations should be further investigated.