Over the last two decades, olive groves in Andalusia have expanded by about 115,000 hectares. This growth encroaches on the habitat of steppe birds, including the little bustard, a species closely tied to the Andalusian countryside and currently showing signs of decline.
Both birds are listed in the threatened categories of the Andalusian catalog of wild flora and fauna because the shift toward intensive crop landscapes and the gradual loss of traditional farmland habitats increasingly affect them.
At the national level, the bustard is classified as endangered while the little bustard is listed as near threatened in the 2021 Red Book of Spanish Birds published by SEO/BirdLife. What factors are risking their survival?
These steppe birds often inhabit open meadows and fields of annual crops such as grains, as well as rural areas. Yet olive trees, being a perennial crop, drive a structural change in land use that harms these species as groves spread beyond traditional patterns.
Dense olive groves increasingly replace scattered trees and shrubs, with high tree densities—ranging from about 200 to 500 trees per hectare compared with roughly 100 in traditional settings—pushed by the pursuit of profitability. This shift contrasts with the expansive, mostly treeless landscapes that support bustards and other large ground-dwelling birds.
Indeed, the expansion of olive cultivation is transforming steppe environments into large continuous habitats that threaten the species living there. A study from the University of Córdoba and the Technical University of Manabí (Ecuador), supported by data from the Corine Land Cover satellite database, analyzes how land use is changing on a continental scale.
Across an 18-year span from 2000 to 2018, new olive groves occupied between 2.14% and 2.16% of the Eurasian bustard and bustard habitat in Andalusia. The spread of woody crops increasingly reduces crop fields, fragmenting the Andalusian landscape and erasing critical habitats for these birds.
Protect key areas by restricting cultivation
Researchers urge urgent policy action to shield the range of these two threatened birds from further olive expansion, especially in designated hotspot zones for courtship and nesting.
As José Guerrero Casado, a researcher in the Department of Zoology, notes, safeguarding bird habitats requires concrete steps. The Birds and Biodiversity Important Areas framework recognizes sites that must be protected to sustain bird populations, and calls for reassessing the boundaries and management of these IBAs.
The study shows thousands of hectares of olive groves located within IBAs that are meant to protect bustards and other species.
While the recent two-decade expansion of olive groves has not dramatically increased in quantity, the qualitative shift is clear. Farmland once devoted to cereals now hosts dense olive plantings, contributing to habitat loss and fragmentation that compounds over time, according to José Eugenio Gutiérrez, SEO/BirdLife representative for Andalusia and head of the Life Olivares Vivos + project.
Researchers also lament the absence of a robust legal framework to safeguard Areas Important for Birds and Biodiversity. They propose that the European Union’s Common Agricultural Policy for 2023–2027 include measures to sustain open cultivation areas, ensure better profitability for farmers, and provide subsidies to discourage conversion of open lands into dense olive groves.
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