Habitat use of the mistle thrush (Turdus viscivorus): The importance of urban areas and permanent crops

Abstract

The mistle thrush is a species that occurs in old-growth forests, especially coniferous forests, in hilly and mountain areas and avoids warm and dry areas and human settlements. Despite this, in recent decades, the mistle thrush has colonised Apulia, southern Italy's lowlands and coasts, in rural and urban contexts. This study investigates the habitat selection of this species in central Apulia, in both the breeding season and winter, by carrying out 301 point counts and 264 linear transects. Data were collected to build a Species Distribution Model (SDM) for each season with the MaxEnt algorithm and the regional land use map, selecting variables through the Akaike Information Criterion. Overlap in the suitability of both seasons was measured using Schoener's D. A total of 133 observations of mistle thrush were noted during the breeding season and 85 observations during winter. During the breeding season, the mistle thrush selected olive orchards, especially those near vineyards and urban areas, where it could find food and safe places to nest. In this period, however, it was also found in coniferous woodlands. The mistle thrush also used vineyards in winter, whereas it avoided urban areas in this period, possibly due to food scarcity. Non-irrigated arable lands were avoided all year round, whereas natural grasslands were only avoided during the winter. Irrigated arable lands positively affected the species. Furthermore, 60% of habitat characteristics were similar between the breeding and winter seasons. It is unclear what makes the mistle thrush shift its range southward and downslope. However, it is likely due to the general increase in forest cover, a positive rainfall trend in Central Italy during summer, and the absence of competition with similar species in central Apulia.