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Titre :	[Winter distribution of Ring-necked Parakeet Psittacula krameri in Cologne.]
Auteurs :	Angelica Kahl-Dunkel, Auteur ; Richard Werner, Auteur
Type de document :	Article
Dans :	Vogelwelt (Die) (123(1) 2002)
Article en page(s) :	17-20
Résumé :	Since 1967 Ring-necked Parakeets are known to live in the Cologne area. When preparing a map of the breeding bird population of Cologne, we asked the public to assist in locating resting/sleeping places at which these birds might spend the nights in winter. Nine members of the local ornithological society then surveyed the winter population by a simultaneous count. All reported resting sites turned out to be places of assembly, i. c. 'stop-over' sites from which the Cologne parakeets, numbering about 630-650 in 1998, 765-800 in 1999 and nearly 1000 in the next three years, continued their flight, sometimes after sunset, in flocks coming from all directions to their communal roost site in the northern part of Cologne. This roost site has been known for many years. During the day, the parakeets dispersed over an area of about 20-30 km in diameter. The distance between the central roost site and the out-lying feeding sites of some of the birds was up to 15 km. When passing this distance, the birds often follow lines of vegetation bisecting the city such as parks, tree avenues and railway lines with accompanying allotments and hedges. Built-up areas are only crossed when 'green lines' are absent. Even though the parakeet's plumage is of a striking green and their flight takes them at great speed across the city, they are rarely seen. They fly in a dense formation at low height and are absolutely silent in flight. Only single birds or late-comers are drawing attention with their loud screeches. Two flight routes together with their stop-over sites have been identified. The parakeets meet other parakeets living there and then proceed together to the next stop-over place. Two further flight routes have been under observation and there are indications of at least one stop-over place on each. A possible explanation for using the central communal roost site may be the warmth and comfort the birds derive from sitting close together. Three only medium-sized silver maples Acer saccharinum serve as perches and the birds sit closely huddled together and may thus protect each other from the cold of the winter nights. Similar long-distance flights to communal roost sites by other species of parrots and parakeets have been observed in tropical regions. Finally, the situation of the parakeets as newcomers in Cologne is discussed.

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