A novel parakeet-selective feeder for control of invasive psittacines

Over 40 species of parrots, members of order Psittaciformes, have established nonnative populations globally. Monk parakeets (Myiopsitta monachus) are among the most invasive bird species worldwide. In their introduced range, populations of monk parakeets have caused negative impacts on native species, habitats, economies, and human safety. Lethal population management has been complicated by the intelligence of monk parakeets, as they quickly alter behavior to avoid risks. Further, lethal control programs have been halted due to public controversy, as parakeets are highly charismatic. The contraceptive DiazaCon has been demonstrated to effectively reduce fertility in monk parakeets and other psittacines. In field applications, chemical control agents (e.g., toxicants and contraceptives) must be delivered in a manner that prohibits access by nontarget species. We developed and tested a parakeet-selective feeder. The feeder allows access by parakeets and limits access by nontarget bird species by lowering a wire exclusion curtain around the feeder, requiring a zygodactyl toe arrangement to access food. We tested the parakeet-selective feeder in trials with captive and free-ranging monk parakeets and nontarget species in Florida, USA. Monk parakeets successfully accessed food from the parakeet-selective feeder throughout the study. The mean number of daily feeder uses by nontarget species decreased from a high of nearly 16 uses per day when the exclusion curtain was not implemented to <1 use per day when implemented. Our findings suggest the parakeet-selective feeder is a promising tool for delivery of bait treated with chemical control agents to manage monk parakeets and other nonnative parakeet populations, but implementation success will likely vary by target species, location, local faunal diversity, and availability of alternative forage.