Control of invasive ring-necked parakeet (Psittacula krameri) in an island biosphere reserve (La Palma, Canary Islands): combining methods and social engagement.
The ring-necked parakeet (Psittacula krameri) has been naturalised in La Palma Island Biosphere Reserve since the late 1990s. Due to landowners' complaints about the impact of parakeets on crops, a control scheme was implemented to eliminate the known population, initially estimated at 70 birds. The programme finally comprised three different phases. Between December 2015 and September 2016, 107 parakeets were removed by trapping using 14 decoy traps. Due to inefficient handling and trap shyness developed by the parakeets, traps were removed from October 2016 to November 2017, with at least 20 parakeets remaining in the wild. The control measures restarted in December 2017; 34 parakeets were counted and 13 were trapped. Since the parakeets had started to breed, the method was changed from trapping to shooting, to remove the last 34 parakeets. In total, during the entire project (December 2015-May 2018), 175 ring-necked parakeets were managed: 154 removed from the environment, 1 handed over to the project staff, and 20 registered by authorities as pets. Considering the undetermined number of ring-necked parakeets kept as pets on the island, an early detection and rapid response system has been set up by the island council, engaging public workers and volunteers to investigate and control new escapes. This project is one of the few cases worldwide where naturalised breeding populations of this invasive species have been successfully eliminated from the environment. Negative effects on biodiversity and human interests were thus minimized, and especially important, this was achieved without generating any social conflict.