Eradication of invasive rabbits restores animal and plant communities on a Patagonian island
Abstract
The European rabbit (Oryctolagus cuniculus) has invaded different ecosystems worldwide, causing extensive ecological degradation through overgrazing and ecological disruption, particularly on islands. Although rabbits have long been present on many islands in southern Argentina and are known to cause noticeable environmental changes, their impacts on native biological communities remain poorly documented. We evaluated the outcomes of a rabbit eradication program on Isla Valdés, in Patagonia, Argentina, combining field-based and remote sensing techniques. We quantified changes in plant community structure and productivity, and animal community composition before and after rabbit removal. We also assessed the impact of the eradication program on non-target species and the costs of the intervention. Using brodifacoum pellets and targeted follow-up control measures, we successfully eradicated rabbits from the island, removing at least 790 rabbits during the 74 days following poison bait application. After rabbit removal, vegetation surveys revealed localized improvements in plant community structure, including increased species richness, greater forage availability, and reduced bare soil. Furthermore, remote sensing analysis showed a consistent increase in the soil-adjusted vegetation index (SAVI) across the island, consistent with improved ecosystem functioning. Camera-trap data also revealed an increase in animal species richness and diversity, together with reduced species dominance, indicating the recovery of a more balanced animal community. Mortality of non-target species was documented, but no measurable effects on indicators of population abundance were detected. A detailed cost assessment revealed a total expenditure of USD 27,735 (USD 282 per hectare). This study shows that rabbit eradication on Patagonian islands is feasible, ecologically beneficial, and likely replicable across Argentina and South America.