Exotic birds spread in Bonn Alexandrine parakeets displace collared parakeets in Bonn
Poppelsdorf · Alexandrine parakeets are conquering Bonn and competing with their smaller relatives, the collared parakeets. Bonn ornithologist Esther Koch estimates that there are 30 of them.
A new species of parrot is competing with the collared parakeet population. "The Alexandrine parakeets have been living in Cologne for a long time, but here in Bonn they have only been breeding for two years," says Bonn ornithologist Esther Koch. Currently, there are about 30 birds in the city, which first bred at the old cemetery, but now also at the LVR clinic. The population will now presumably also increase in Bonn and further displace the collared parakeets, who consequently have to look for new breeding sites, but currently still have a significantly larger population of about 2,000 birds. "So one neozoa is displacing the other," Koch notes. Both parakeets feed in the same way and therefore have the same breeding sites. Due to their size, the Alexandrine parakeets are superior to the collared parakeets and thus dominant.
Ulrich Heide from Bonn, who lives in Poppelsdorf near the Botanical Garden, has already noticed the Alexandrine parakeets. "I have never seen a flock of at least 30 birds swoop down on my trees and systematically remove the already brown outer shell, then peck open the nut to eat only the tasty kernel," he says. This year was the first time he noticed "systematic harvesting". "This time practically all the nuts were eaten," Heide explains.
Nets help against nut thieves
But what could be done to protect against the flying walnut thieves? "Put a net over the tree. It's the same procedure that is used in orchards, for example, to protect cherries from birds," explains graduate biologist Esther Koch. Heide doesn't want to do anything about the parrots, though: "On the one hand, the spectacle was very exciting to watch, on the other hand, I don't have to live from selling my walnuts. The eagerness, the precision in the details of shelling and also the small conflicts in the flock were really interesting to watch," he thinks. In addition, he says, the Alexander parakeets no longer paid attention to the nuts that fell on the ground. "So they have a high demand for quality," says Heide.
His neighbour Markus Delfosse also had "enough left over for his own use". Although he also notices the growing population, he is nevertheless happy about the visitors. Besides walnuts, the parakeets feed on buds, leaves and fruits, among other things, so "mainly vegetarian food", explains Koch. In the region, they "mainly occur in the Rhine region and avoid higher altitudes". For breeding, they prefer parks and cemeteries with old trees.
The natural range of the Alexander's parakeet extends from Afghanistan and Pakistan through India, Burma and Thailand to Laos, Cambodia and Vietnam. They also inhabit Sri Lanka and the Andaman Islands. Smaller populations can be found in Cologne and Bonn as well as in Wiesbaden and Mainz.
Collared parakeets are more widespread than Alexandrine parakeets
According to Koch, the small relatives of the Alexandrine parakeets, the collared parakeets, are the most widespread parrot species worldwide. They originate from Africa and India. Although they have been kept as pets in Germany and Europe for centuries, they have only existed in the wild in Germany since the 1970s. At that time, a larger number had escaped in Cologne, and they established themselves in urban areas. In 1979, the first breeding was recorded in Bonn, reports Koch, who wrote her diploma thesis on the collared parakeets.
Original text: Marco Rauch
Translation: Mareike Graepel
