News News

The costs of mischoosing are not uniform across individuals

250

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
Average (0 Votes)

Latest News Latest News

Back

Is restocking a useful tool for increasing rabbit densities?

Is restocking a useful tool for increasing rabbit densities?

The European rabbit Oryctolagus cuniculus is endemic to Mediterranean ecosystems in the Iberian Peninsula, where it is a key species. In recent years its populations have declined due to several factors including habitat transformation and viral diseases. At the same time, corrective measures including population restocking in areas with low population densities using rabbits from other geographical areas have been performed. In this study we evaluate the impact restocking has had on the population dynamics of native rabbits in the Doñana National Park. As part of the natural processes monitoring program carried out in the Doñana Biological Station (ESPN-EBD-CSIC), rabbit censuses were conducted in spring and late summer in 2005–2015?at dusk and at night along six fixed transects in habitats harbouring rabbit populations. In order to take into account restocked rabbit numbers, annual reports from the Doñana Natural Area and data provided by the Lynx team of the LIFE project were incorporated into the study. In all, 52?336 rabbits from different parts of western Andalusia were released in the Doñana Biosphere Reserve in 2005–2015. Yet, rabbit populations underwent significant declines, above all in 2013 and 2015, with decreases in some areas of up to 80%. These results show intensive rabbit restocking did not increase the native rabbit populations numbers. The impact of the release of rabbits on the population dynamics of the species in Doñana is discussed. informacion[at]ebd.csic.es: Carro et al (2019) Is restocking a useful tool for increasing rabbit densities? Global Ecol Conserv https://doi.org/10.1016/j.gecco.2019.e00560


https://www.sciencedirect.com/science/article/pii/S2351989419300198