SOVON (1988) Actualities: Annual PTT project. LIMOSA 61 (2): 98-98.

Point-transect-counts project (PTT) is the longest running the monitoring of projects SOVON. the first census was conducted in December 1978. From 1983 to in November, December and February a large number of routes at present counted winter birds. the results give an impression of the numbers and distribution of winter birds. Furthermore, an impression changes in the numbers and distribution within a winter and from year to year. than one year back appeared on the season 1983/84 a annual report, the results are detailed by type elucidated. Recently rolled the annual 1984-1985 was published

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