Monitoring and modeling non-native invasive green iguana population response to harvesting on Grand Cayman, Cayman Islands

Registered hunters harvested over 1.3 million non-native invasive green iguanas (Iguana iguana) on Grand Cayman between October 2018 and August 2021. We used islandwide post-reproduction survey-based abundance estimates in August 2014–2021 and model-based abundance predictions for August 2022–2030 to assist natural resource managers with reassessment and modification of the harvest strategy due to diminishing returns to hunters paid per green iguana harvested. We need harvest rates > 0.600 for desired abundance ≤ 50,000 and > 0.700 for desired abundance ≤ 10,000 green iguanas. With harvest rates < 0.600, the population would likely remain above desired abundance. Without harvesting, the green iguana population would likely reach carrying capacity by August 2026.