Alarming decline of the Little Bustard Tetrax tetrax in one of its two population strongholds in Sardinia, Italy

Abstract

Summary Farmland biodiversity is declining worldwide, and especially in Western countries largely owing to the large-scale intensification of agricultural practices. The Little Bustard Tetrax tetrax is a steppe bird adapted to agro-pastoral ecosystems in Western Europe, and is one of those many farmland species declining due to changes in agricultural production systems. In the EU, the majority of the extant population of this species is concentrated in the Iberian Peninsula. In Italy, the species has now disappeared from the mainland and is currently present only in Sardinia, where two populations, in the central-western areas, hold about two-thirds of the whole island’s numbers, with the rest scattered across numerous smaller nuclei. While there are indications and anecdotal information suggesting a possible population decline during recent decades, robust monitoring across different time periods that would allow a comparison of numbers is lacking in Sardinia. Here we repeated a Little Bustard survey performed in 2008 in two areas of western Sardinia: Abbasanta, which is one of the two strongholds for the species in Sardinia, and Campeda, which holds a small population (about 10 territorial males). Using the same methodology as in the past survey, we assessed current population size and density, and quantified changes over time. We found alarming declines, at a rate of around 30% in 14 years in both areas, with an estimated current population of 87 males in Abbasanta and 8 males in Campeda. We highlight current and emerging threats, such as the downsizing of the Special Protection Area of Abbasanta, and the encroachment of solar power plants within the same area.