Studying intraspecific spatiotemporal variation in vital rates among populations over a range of environmental conditions is essential to reveal intrinsic and extrinsic factors affecting population dynamics. Mammal populations living at higher elevations often have higher adult survival, shorter breeding seasons, and lower reproductive output per season than at lower elevations. We studied dynamics of a Eurasian red squirrel (Sciurus vulgaris) population in high-elevation, mountain pine (Pinus mugo) forest with extreme winters, in the Central Italian Alps, and compared vital rates with populations in more productive habitats at lower elevations. Average density was 0.14 ± 0.07 squirrels ha−1 (range 0.07–0.30 ha−1), and numbers typically increased in summer–autumn as a result of seasonal reproduction and immigration. Mean persistence time was only 12.5 months, and there was a nearly complete population turnover in only two years. Local survival and recruitment rate were correlated with seasonal population growth rate, and partial effect of survival explained 80% of variation in growth rate. While reproductive rate in mountain pine habitat was more similar than in more productive habitats at lower elevations, density and autumn–winter survival were much lower. Thus, red squirrels did not show the adaptations observed in several other mammal species, but might invest heavily in early reproduction to compensate for short life expectancy.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.