Towards Practical Application Of Emerging Fertility Control Technologies For Management Of Rose-Ringed Parakeets

Abstract:
Rose-ringed parakeets have recently become established in cities across Europe including London, where they are now commonly seen in parks and gardens. Concerns regarding impacts on native birds as well as noise and damage to horticultural interests, have prompted increasing interest in management of populations to reduce numbers. However, parakeets are also regarded by many people as a charismatic and colourful addition to our native fauna, and hence use of lethal methods is increasingly likely to meet with public opposition. We previously found that a cholesterol inhibitor, which has been used for control of feral pigeons, significantly reduced fertility rates in captive Rose-ringed parakeets with no obvious negative effects on welfare. The effects are temporary but not species-specific, which means that targeted delivery systems are required before the method is likely to gain approval for use in the field in the UK. We developed and tested two types of weight-operated feeder using untreated test baits in captivity and then in the field. Feral parakeets successfully fed from the feeders, but non-target corvids and grey squirrels were also able to access the baits. Further development of species-specific delivery systems is required before non-lethal control of Rose-ringed parakeets by using oral contraceptives is feasible.