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Lack of evaluation of the effectiveness of conservation practices as well as the challenge of converting scientific knowledge into conservation legislation and policy are persistent problems in conservation biology. European Union's Habitats Directive obliges member states to establish and implement a system of strict protection of animal species listed in Annex IV(a). This implies for example, that the deterioration or destruction of breeding sites or resting places of these species is prohibited. Here, we evaluate the effectiveness of the protection procedure aimed at conserving sites occupied by the Siberian flying squirrel Pteromys volans from destruction as a consequence of timber harvesting. We assess the potential effectiveness of the protection procedure by combining survey data with a simulation approach, showing that c. 97% of forests occupied by the species are harvested without authorization, as a result of inadequate information on the occurrence of the species. We assess forest structure around our study sites, visited both at the time of the protection decision and 1-6 years later, and show that clear-cut areas within 150 m of breeding sites and resting places substantially increase the risk of abandonment. In spite of this, typically only areas of radius 10-30 m are protected from logging. As the territory is abandoned in c. 50% of the cases in spite of protection of breeding sites and resting places, the total effectiveness of this conservation measure is only c. 1.5%. Therefore, the current protection measure is inadequate against the threats that forestry poses for the species in Finland, and the focus should be turned to habitat and population level solutions. We suggest that researchers and decision-makers should pay more attention to the overall effectiveness of different conservation measures, as this information is crucial for developing effective conservation policies.

Climatic conditions, trophic links between species and dispersal may induce spatial synchrony in population fluctuations. Spatial synchrony increases the extinction risk of populations and, thus, it is important to understand how synchrony-inducing mechanisms affect populations already threatened by habitat loss and climate change. For many species, it is unclear how population fluctuations vary over time and space, and what factors potentially drive this variation. In this study, we focus on factors determining population fluctuations and spatial synchrony in the Siberian flying squirrel, Pteromys volans, using long-term monitoring data from 16 Finnish populations located 2–400 km apart. We found an indication of synchronous population dynamics on a large scale in flying squirrels. However, the synchrony was not found to be clearly related to distance between study sites because the populations seemed to be strongly affected by small-scale local factors. The regularity of population fluctuations varied over time. The fluctuations were linked to changes in winter precipitation, which has previously been linked to the reproductive success of flying squirrels. Food abundance (tree mast) and predator abundance were not related to population fluctuations in this study. We conclude that spatial synchrony was not unequivocally related to distance in flying squirrels, as has been observed in earlier studies for more abundant rodent species. Our study also emphasises the role of climate in population fluctuations and the synchrony of the species.Electronic supplementary materialThe online version of this article (10.1007/s00442-019-04537-3) contains supplementary material, which is available to authorized users.

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