Invasive parakeets could force out native birds

With their cheery green feathers and red beaks, rose-ringed parakeets might seem like a welcome addition to cities. But this invasive species, which has infiltrated urban areas around the world, is keeping native birds away from their food.

Researchers studied the effects of rose-ringed parakeets at 41 gardens in and around London. At each site, they set up a feeding station with sunflower seeds and peanuts. Then the team recorded the behavior of visiting birds, including how long they stayed at the feeder and whether they ate anything, under different sets of conditions. Sometimes a caged parakeet was present, or an audio recording of a parakeet call was playing, or both. As a control, the researchers also tested the effects of having a caged native woodpecker present, a woodpecker call playing, or simply an empty cage.

The study authors observed 10,893 bird visits to the sites and identified 18 native species. Most of the birds were blue tits or great tits. At sites in the parakeet’s range, fewer native birds visited the feeder if a caged parakeet was present; they also spent less time eating and more time acting vigilant. Woodpeckers deterred visitors too, but not as much as the parakeets did.

The researchers found similar trends at sites outside the parakeet’s range. But even fewer of the visiting birds ate at the feeders with parakeets, perhaps because they weren’t as used to the invasive birds.

The results are probably conservative, the authors add, because feeders are often swarmed by entire flocks of rose-ringed parakeets. Native birds that stay away from those food sources may suffer from lower energy levels, and their numbers could eventually drop. To protect them, people may need to figure out ways to let native birds eat at the feeders — but keep parakeets out.Roberta Kwok | 27 March 2014

Source: Peck, H.L. et al. 2014. Experimental evidence of impacts of an invasive parakeet on foraging behavior of native birds. Behavioral Ecology doi: 10.1093/beheco/aru025.

Image © Vladimir Kogan Michael | Shutterstock

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2 Comments

  • John Brusen March 27, 2014 at 7:33 pm

    Regarding your interesting story about parakeets in the UK, the situation in Australia (my home now) is also pretty grim w.r.t. introduced species out-competing local birds. Many of those species have actually been introduced from other parts of Australia and have decimated local environments in Western Australia for example. (The Rainbow Lorikeets and the Western Corella are raising hell with local bird life especially w.r.t. dwindling habitat.)

    Suggestions about how to control these pests is welcome.

    Thanks,
    JRB

    Reply

  • Cristiana Senni April 1, 2014 at 12:36 am

    There is no way that study on bird’s behavior at feeders, a totally unnatural situation, can be scientifically considered as an indicator of how the native birds’ populations are faring and of the impact of the parakeets as an introduced species.

    If parakeets killed smaller native birds at feeders, that would be one thing, but you’d have to show that this subtle decrease in feeder use actually corresponds to 1. fitness, and ultimately 2. population trends for this to mean anything like what they’re claiming it does.

    There is no question that the parakeets do not belong in Britain and in the rest of Europe, but scapegoating them for things they aren’t doing distracts from real ecological problems, loss of avian biodiversity across the whole country … even where there are no parakeets.

    If we really want to find out if and how the parakeets are impacting native birds they should be studied in a natural environment.

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