Ongoing major collapse of the Portuguese little bustard breeding population

The third Little bustard (Tetrax tetrax) national survey carried out in 2022 estimated a population of 3944 (min–max: 1425–6823) males in Portugal. This represents a population decline of 77% and 56% compared to estimates of the previous surveys from 2006 and 2016, respectively. The species has greatly disappeared outside SPAs, while the remaining breeding population concentrated within the protected area network is showing a steep decline at a rate of 9% a year.

This steep decline is related to major habitat loss or degradation caused principally by shifts in agricultural policies, with the conversion of extensive cereal-fallow-rotation systems to intensive permanent pastures for beef production over the last few years, including within SPAs. The major expansion of permanent crops (olive and almond) outside SPAs led to overall habitat destruction and, consequently, to range contraction. Other threats are likely acting synergistically such as fragmentation, climate change and anthropogenic mortality, especially related with energy infrastructures.

With no effective measures in place to reverse the situation, the little bustard in Portugal is on its way to extinction in the near future.

More information can be found at https://www.nature.com/articles/s41598-023-36751-8.

Silva, J.P., Marques, A.T., Carrapato, C. et al. A nationwide collapse of a priority grassland bird related to livestock conversion and intensification. Sci Rep 13, 10005 (2023). https://doi.org/10.1038/s41598-023-36751-8