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The costs of mischoosing are not uniform across individuals


Matching habitat choice is a particular form of habitat selection based on self?assessment of local performance that offers individuals a means to optimize the match of phenotype to the environment. Despite the advantages of this mechanism in terms of increased local adaptation, examples from natural populations are extremely rare. One possible reason for the apparent rarity of matching habitat choice is that it might be manifest only in those segments of a population for which the cost of a phenotype–environment mismatch is high. To test this hypothesis, we used a breeding population of sockeye salmon (Oncorhynchus nerka) exposed to size-dependent predation risk by bears, and evaluated the costs of mischoosing in discrete groups (e.g. male versus females, and ocean?age 2 versus ocean?age 3) using reproductive life span as a measure of individual performance. Bear preference for larger fish, especially in shallow water, translates into a performance trade-off that sockeye salmon can potentially use to guide their settlement decisions. Consistent with matching habitat choice, we found that salmon of similar ocean?age and size tended to cluster together in sites of similar water depth. However, matching habitat choice was only favoured in 3?ocean females – the segment of the population most vulnerable to bear predation. This study illustrates the unequal relevance of matching habitat choice to different segments of a population, and suggests that ‘partial matching habitat choice' could have resulted in an underestimation of the actual prevalence of this mechanism in nature. informacion[at] Camacho & Hendry (2020) Matching habitat choice: it's not for everyone. Oikos DOI 10.1111/oik.06932
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Replicate radiations in Caribbean frogs

Replicate radiations in Caribbean frogs

Replicate radiations, the repeated multiplication of species associated with ecological divergence, have attracted much attention and generated as much debate. Due to the few well?studied cases, it remains unclear whether replicate radiations are an exceptional result of evolution or a relatively common example of the power of adaptation by natural selection. The case of Eleutherodactylus frogs is examined here; this group radiated in the Caribbean islands resulting in more than 160 species that occupy very diverse habitats. A time?calibrated phylogeny revealed that these frogs independently diversified on all larger islands producing species that occupy a broad range of microhabitats in different islands. Using phylogenetic comparative methods, we found an association between morphological traits and particular microhabitats, and for most microhabitats detected significant morphological convergence. Results indicate Caribbean Eleutherodactylus are a novel example of replicate radiations, and highlight the predictability of evolutionary processes, as similar ecological opportunities can lead to similar outcomes. informacion[at] Dugo-Cota et al (2019) Ecomorphological convergence in Eleutherodactylus frogs: a case of replicate radiations in the Caribbean. Ecol Lett