Bird feeders may sustain feral Rose-ringed parakeets Psittacula krameri in temperate Europe

摘要

The Rose-ringed parakeet Psittacula krameri , a bird species of subtropical origin, has established feral populations in temperate Europe. We analysed the feeding habits of Rose-ringed parakeets near Paris, France, in order to assess if food provided by humans might contribute to the success of this invasive bird species. We considered 87 feeding events performed during 2002 - 2007 and 247 feeding events performed during March - November 2008. We recorded the consumption of seeds, buds and fruits from many native and introduced shrubs and trees, and the use of bird feeders in private and public gardens throughout the year. We followed four radio-equipped birds for 150 hours during September - December 2008, which spent about half of their feeding time at bird feeders. This confirmed the importance of bird feeders in the diet of the Rose-ringed parakeet. Our study underlines the opportunistic granivorous-frugivorous character of this parakeet species and the possible role of human food sources in the success of its establishment in many cities across temperate Europe.