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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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Effects of uropygial gland secretion on the host seeking behaviour of mosquitoes

Effects of uropygial gland secretion on the host seeking behaviour of mosquitoes

Mosquito feeding preferences determine host–vector contact rates and represent a key factor in the transmission of vector-borne pathogens. The semiochemical compounds of which vertebrate odours are composed probably play a role in mosquito host choice. Birds spread secretions from uropygial gland over their feathers to protect their plumage, comprising behaviour that may in turn affect odour profiles. Although uropygial secretions are expected to modify the attractiveness of birds to mosquitoes, contradictory findings have been reported. Mosquito species differ in their feeding preferences, with some species feeding mainly on birds (ornithophilic species) and others on mammals (mammophilic species). Consequently, it is possible that ornithophilic and mammophilic species differ in their response to uropygial gland secretions. Using a dual-choice olfactometer, the present study tests this hypothesis by comparing the behavioural response to uropygial gland secretions from juvenile male and female house sparrows (Passer domesticus) in the ornithophilic Culex pipiens and the mammophilic Aedes (Ochlerotatus) caspius mosquitoes. No differences were found in the response of either mosquito species to the uropygial gland secretions. Therefore, the preference of ornithophilic mosquitoes for avian hosts is apparently not explained by a greater attraction of mosquitoes to the uropygial gland secretion odour when presented in combination with a CO2-enriched airflow and other, probably additional, factors must be at stake. informacion[at]ebd.csic.es: Díez-Fernández et al (2019) House sparrow uropygial gland secretions do not attract ornithophilic nor mammophilic mosquitoes. Med Vet Entomology DOI 10.1111/mve.12401


https://onlinelibrary.wiley.com/doi/full/10.1111/mve.12401