BRUIJN O DE (1986) Short contributions: The Barn Owl Tyto alba as an indicator species of diverse farmland. LIMOSA 59 (2): 90-90.

Barn Owl Tyto alba Habitat preference, prey selection, and population trend of the Barn Owl have been studied in an area of 900 km2 in the eastern part of the Netherlands over a period of 20 years. Two parts can be distinguished in the study area: a western part mainly consisting of Holocene polder and riverine landscape (Liemers), and an eastern part mainly consisting of Pleistocene landscape types (the Achterhoek). The Barn Owl population in the Achterhoek shows an upward trend, whereas the population in the Liemers is evidently declining in numbers (fig. 1). Habitat analyses showed that the numerical decline of the Barn Owl in many landscape types (ct Braaksma & de Bruijn 1976) can be related for the greatest part to changes in land use and to the disappearance of landscape elements of vital importance to this species. Together with the Barn Owl some 25 other species of breeding birds of diverse farmland appear to be threatened by this development. Detailed results of this study will be published in Ardea.

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