An update on the conservation status of the Little Bustard Tetrax tetrax: global and local population estimates, trends, and threats

The Little Bustard Tetrax tetrax is an iconic species and an indicator of healthy grassland and farmland ecosystems. It formerly ranged almost continuously from north-western Africa and Iberia to central Asia, encompassing France, Italy, southern Russia, and the Middle East, occupying natural grass steppes, pastured grasslands, and extensive cereal farmland. Today, two main distribution sub-ranges persist: a western one comprising the Iberian Peninsula, France, and Sardinia, and an eastern one encompassing mainly southern Russia and Kazakhstan but reaching north-western China and isolated spots in Turkey. We describe the changes that occurred across the species’ range and were documented during the last and current centuries and revise the status and trends of Little Bustard populations throughout that range. We provide the first global estimate of the world population, as well as those of the two sub-ranges, discussing the main threats and global conservation implications of these estimates. Historically abundant in Europe and northern Africa, the Little Bustard has strongly declined over the second half of the 20th century, becoming extinct in at least 15 countries. Such spectacular regression is mainly associated with land-use change and agricultural intensification. Other threats are legal hunting, poaching, and collision with powerlines. In the last two decades, the species has severely declined (c.6% yearly rate) in its traditional population stronghold, the Iberian Peninsula. Conversely, there is evidence of recent population growth in some areas of the Eastern range, but increases are unquantified and require further study. Many populations are probably small and scattered, with no reliable information on size and trends. Nevertheless, the Eastern range may now be considered the species’ stronghold with more than half the world’s population. The diverging dynamics and ecological differences between the two sub-ranges require a global conservation strategy that treats each as a different conservation unit to assure the species’ recovery.