Sheep damaged 30% of Mexico island; removal helped forest cover rise to 85%

Imagine an island where a herd introduced for ranching gradually became one of the biggest threats to its native ecosystem. That is what happened on Mexico’s Socorro Island, where about 100 sheep introduced in 1869 eventually became feral and reached an estimated 5,000 animals by 1960. Over decades, overgrazing contributed to severe vegetation loss and erosion across the island. A 2016 study published in Forests, titled “Recovery of Vegetation Cover and Soil after the Removal of Sheep in Socorro Island, Mexico”, documented how the landscape began recovering after the animals were removed. A separate 2019 study on the island’s ecological restoration recorded the eradication of 1,762 feral sheep between 2009 and 2012.How 100 sheep became an ecological problemSocorro Island is part of Mexico’s Revillagigedo Archipelago in the Pacific Ocean. Covering about 132 square kilometres, it is a volcanic island with a high level of biological endemism.