TAIPEI (Taiwan News) — Kaohsiung will step up efforts to control its invasive green iguana population in September by offering NT$300 (US$9.46) vouchers for each qualifying adult iguana removed by trained and certified members of the public.
The Kaohsiung City Government Agriculture Bureau said the new strategy will shift the focus from maximizing the number of iguanas removed to targeting mature animals capable of reproduction, per CNA. The city will prioritize iguanas with a snout-to-vent length of at least 30 centimeters.
The bureau said it is prioritizing mature iguanas to make better use of limited manpower rather than spending resources primarily on juveniles, which have a relatively low chance of surviving to adulthood. Juvenile green iguanas face threats from predators, food availability, and environmental conditions, and their first-year survival rate is less than 5%.
Green iguanas enter their breeding season from about October through February. During this time, males develop orange-red coloration and display more pronounced territorial and courtship behavior.
These changes during mating season can provide clues for identifying adult iguanas and breeding hotspots. Females reach sexual maturity at about 2 to 3 years old and can lay up to 70 to 80 eggs in a clutch, according to the Kaohsiung Museum.
Kaohsiung had removed 27,654 green iguanas as of Aug. 25, with Niaosong District accounting for the largest number at 9,661. Daliao District followed with 4,145, while Linyuan District recorded 3,644, per the Forestry and Nature Conservation Agency.
The Agriculture Bureau said it has conducted five training sessions for members of the public, with 626 people completing the training and obtaining capture identification certificates. Other southern Taiwan counties and cities will adopt a similar voucher system targeting adult green iguanas to strengthen regional control efforts, the bureau said.
The Forestry and Nature Conservation Agency said local governments removed about 260,000 green iguanas nationwide last year, a record and roughly three times the 2024 total. Pingtung County recorded the most removals, with 130,288, followed by Kaohsiung with 62,608.
Green iguanas have also been reported as far north as Miaoli and Hsinchu. The agency has been working with local governments to strengthen patrols and prevent their further spread. Native to tropical regions of Central and South America, green iguanas can grow to between 1.8 and 2 meters long, with the tail accounting for about two-thirds of their total length.
