Predictors of extinction risk of passerine birds in aCentralEuropean country

Abstract

AbstractTo develop effective conservation measures, it is crucial that we understand how ecological and life‐history traits relate to risk of species extinction. Through the use of phylogenetic generalized least‐squares regression, this study assesses the relative importance of habitat specialization, life history, migration strategy and climatic niche as predictors of national threat level for 86 passerine bird species breeding in theCzechRepublic. We found that, after controlling for variation in breeding distribution, slow life history increases the extinction risk in habitat specialist species, but reduces such risk in habitat generalists. The higher threat of habitat specialists is consistent with their higher sensitivity to human‐induced environmental perturbations, most notably to the habitat loss. However, our results suggest that the negative effects of habitat specialization appear to be somewhat compensated for by fast life history. For example, species with fast life histories typically display higher fecundity than species with slow life histories. At the same time, slow life history can be beneficial for habitat generalists that are not as badly affected by habitat destruction as habitat specialists. Such species are able to allocate more energy to future reproduction and could wait for optimal environmental conditions before breeding, leading to more favourable population status in the long term. Finally, we also found that species breeding in warmer areas experience higher extinction risk than species breeding in colder areas. Although the effect of climatic niche is usually attributed to the impact of climate change, we suggest that the habitat destruction is more likely an explanation because the warmer lowland regions are heavily exploited by intensive agriculture and industrial and urban development. Based upon these results, we suggest that current conservation effort, especially in warmer zones, may not sufficiently address the requirements of the habitat specialists with slow histories.