KEIJL GO (2001) Ring-necked Parakeets Psittacula krameri in Amsterdam, 1976-2000. LIMOSA 74 (1): 29-31.

The population of Ring-necked Parakeets in Amsterdam has grown from two individuals in 1976 to 430 in January 2000, as assessed from counts at communal night roosts. During the first years, most parakeets were observed in and around two parks in the southwest and south of Amsterdam, but since about 1990 they are also seen in other parts of the city during daylight hours, and since 1998 up to twelve kilometers outside Amsterdam. However, probably all birds return to one roost in Amsterdam to spend the night. At least part of the population uses a communal roost throughout the year. Up to early spring 2000, the parakeets have used nine different roosting sites (Tab. 1). They sometimes shift between sites for unknown reasons, sometimes several times within a couple of weeks. This parallels the situation in England (Pithon & Dytham 1999). Most roosting sites lie in the western part of Amsterdam. The majority of roosts are in high (> 12 m) deciduous trees close to water. The site most regularly in use lies at a busy roundabout. Ring-necked Parakeets in Amsterdam start the breeding season from March onwards. There are no data on breeding numbers, but it is believed that the numbers present on the roost alter March represent the non-breeding population; thus, the present breeding population is estimated at 100 pairs. From the population growth rate (22.5% per year between 1994-2000) it is concluded that the breeding success must be low (probably less than one fledged young per pair). This is also similar to the German and English situation. Although the parks where Ring-necked Parakeets occupy nesting cavities in trees still hold populations ol other hole-nesting birds, the influence of Ring-necked Parakeets on native breeding birds and tree-dwelling bats remains unknown, since the original situation has not been described.Rose-ringed Parakeet Psittacula krameri

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