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The costs of mischoosing are not uniform across individuals

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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]ebd.csic.es: Camacho & Hendry (2020) Matching habitat choice: it's not for everyone. Oikos DOI 10.1111/oik.06932


https://onlinelibrary.wiley.com/doi/full/10.1111/oik.06932
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Iberian amphibians occupy higher mountain areas compared to the last century

Iberian amphibians occupy higher mountain areas compared to the last century

Current climate warming has already contributed to local extinctions. Amphibians are one of the most sensitive animal groups to climate change, currently undergoing a global decline. Predictive models for Europe and Iberian Peninsula forecast that the future impact of climate change on amphibians will depend on their capacity to alter their distributions by tracking climate warming. In the present study, the responses of Iberian amphibian species to recent climate change are explored by comparing amphibian distributions between two time periods (1901–1990 vs. 2000–2015). Findings suggest that, although climatic conditions have changed between the two periods, Iberian amphibians have barely shifted their distribution ranges northwards, with the exception of the southernmost species Alytes dickhilleni. However, most Iberian amphibians appear to have moved their elevational limits upwards in mountains. Approximately half of the species showed different occupied niches between the two time periods, suggesting that many Iberian amphibians have not been able to reach all the new location with optimal climatic conditions for them. Furthermore, disappearing cold climatic conditions (e.g. those found at mountain tops) limit the potential distribution of cold-adapted species, including European widespread species with their southern margin in the Iberian Peninsula, and endemic species. The combination of a limited ability to shift their ranges and profound climatic changes could pose a challenge to the long-term persistence of Iberian amphibian populations. informacion[at]ebd.csic.es: Enriquez-Urzelai et al (2019) Are amphibians tracking their climatic niches in response to climate warming? A test with Iberian amphibians. Clim Chang DOI: 10.1007/s10584-019- 02422-9


https://link.springer.com/article/10.1007%2Fs10584-019-02422-9