Livestock Farming Threatens Biodiversity and Human-Modified Environments

Researchers studying the dependence of Eurasian griffon vultures on carcasses from intensive livestock farming have found alarming results. The rise of intensive livestock farming poses a significant threat to biodiversity, particularly for species that rely on carcasses for sustenance. The study analyzed GPS-tracking and stable isotopes of 77 vultures in the Iberian Peninsula, revealing that the birds' diets vary depending on the level of human transformation of landscapes and individual characteristics.

Key Takeaways:

• The study found that Eurasian griffon vultures rely heavily on intensive livestock farming, including pig and sheep farming, in human-modified environments.
• The birds' diets vary depending on the level of human transformation of landscapes, with populations in areas with higher Human Footprint Index showing utilization of varied livestock resources.
• Stable isotopes proved valuable in assessing the real avian scavengers' reliance on carrion resources on a broad scale, surpassing estimates from widely-used methods.
• The dependence on intensive livestock farming threatens individual health and population viability due to ingestion of veterinary drugs, pollutants, and direct mortality from infrastructure accidents.
• The study suggests that the use of stable isotopes is a more accurate way to assess the reliance of avian scavengers on carrion resources.
• The research highlights the importance of considering the impact of human activities on ecosystems and the need for sustainable practices in livestock farming.

Statistics:

• 77 Eurasian griffon vultures were tracked using GPS and stable isotopes in the Iberian Peninsula.
• 60% of the vultures' diet consisted of pig consumption, likely due to their reliance on corn-derived feed supplements.
• 30% of the vultures' diet consisted of sheep consumption, with variations linked to home range size changes.
• 10% of the vultures' diet consisted of pig remains from vulture feeding stations and farms.

Sources:

• Livelihood in anthropic landscapes: Stable isotopes as indicators of dependence of obligate avian scavengers on intensive animal farming. Ecological Indicators, 2025, 174(): 113467.
• Instituto Espanol de Oceanografia (IEO-CSIC)
• Instituto Espanol de Oceanografia (IEO-CSIC), Centro Oceanografico de Malaga (COMA), Malaga, Spain (journalist contact)