Comparisons were made of the densities of breeding populations of Magpies in 33 plots covering a total of 581.5km² in various types of agricultural landscape in Poland. The majority of plots had areas in the range 1.4 to 100km². Data used in further analysis were those from plots including all the environments making up the agricultural landscape, i.e. arable land, meadows, pastures, villages, areas of trees in fields, and orchards. Plots were taken to represent agricultural landscape outside river valleys, or 3 types of river valley landscape (with meadows, with orchards and ox-bows and with fields and ox-bows). The 24 plots (total 488.8km²) in the predominantly arable-field landscape supported a mean density of 0.8 pairs of Magpie per km² (range 0.3-3.0 pairs/km²), while the 9 plots in river valleys (92.7km²) had a mean of 2.9 pairs/km² (range 0.7-7.1). The highest densities (1.1—7.1 pairs/km²) were noted for meadow landscape on semi-natural floodplain terraces. High densities of 2.0-4.0 pairs/km² were also noted from plots in the most transformed valley landscape with ox-bows and orchards covering >20% of land, but the agricultural landscape with ox-bows (predominantly arable but with limited representation of orchards) had a mean density of 1.0 pairs/km². In the years 1979-1984, the mean densities for field plots in western and eastern Poland were 1.15 and 0.58 pairs/km² respectively. Plots in the agricultural landscape of western Poland were characterised by increasing abundance, or by no change in numbers, while comparable ones in the east sometimes even showed declines (in contrast to the increasing populations noted in the towns and cities of east-central Poland).
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