Non-breeding ranging behaviour, habitat use, and pre-breeding migratory movements of Fieldfares (Turdus pilaris) wintering in southern Europe

Abstract

Improving our understanding of the spatio-temporal distribution of migratory game species is pivotal for developing flyway-based management strategies. We used miniaturized GPS-Argos transmitters to analyse movement patterns, home-range, habitat use, and pre-breeding migratory dynamics of a medium-sized (~ 80 g) migratory songbird, the Fieldfare (Turdus pilaris). We focused on the population wintering in northern Italy, an area where this species is subject to intense hunting pressure during autumn–winter. Most individuals were relatively sedentary upon reaching their wintering area, with only a few performing erratic movements up to mid-January. Forest and farmland were the most used habitats during both early and late winter. We obtained partial information on pre-breeding migration from 16 individuals. Pre-breeding migration began on 21 March on average (min.: 7 March, max.: 7 April). We identified north-western Russia (longitudes 35–50° E) as the putative breeding area of six individuals, while a single individual migrated to Finland. Our novel individual-based tracking study of south-European wintering Fieldfares thus highlights that Russia, rather than Scandinavia, is likely the main origin area for Italian wintering birds, improving previous knowledge based on recoveries of ringed birds. Our findings suggest that an effective flyway-based management plan for a sustainable exploitation of the Fieldfare in southern Europe may be hindered by knowledge gaps on the conservation status of this species over its broad breeding range, which extends to distant Russian regions.