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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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Global geographic patterns in the colours and sizes of animal dispersed fruits

Global geographic patterns in the colours and sizes of animal dispersed fruits

Fruit colours attract animal seed dispersers, yet the causes of fruit colour diversity remain controversial. The lack of knowledge of large?scale spatial patterns in fruit colours has limited our ability to formulate and test alternative hypotheses to explain fruit colour, fruit size and fruit colour diversity. Spatial (especially latitudinal) variation in fruit colour, colour diversity and length has been described, and tested for correlations between fruit colour, length and plant habit, assembling a database of fruit traits for 13,178 fleshy fruited plant species spanning 136 sites around the world. Fruit length (both mean and variance) increases towards the tropics. Tropical communities tend to have diverse fruit colours, including many mammal?associated fruit colours (green, orange, brown and yellow), while high latitude communities contain a higher percentage of red?fruited species. The correlation between colour and size is strong, and some latitudinal patterns may be partly driven by changes in fruit size. Fruits may be larger in the tropics than at high latitudes because dispersers in the tropics tend to be larger, but there are other possible explanations. The Northern and Southern Hemispheres differ in the diversity of fruit colours across latitude, with the Southern Hemisphere having higher colour diversity, similar to the tropics. Differences in geography and in the history of plant lineages in the Southern versus the Northern Hemisphere may help to explain some biogeographic patterns, but alternative hypotheses related to fruit defence, development and metabolic costs are plausible. informacion[at] Sinnott-Armstrong et al (2018) Global geographic patterns in the colours and sizes of animal-dispersed fruits. Glob. Ecol. Biogeography