EERDEN MR VAN & ZIJLSTRA M (1984) Actualities: Colour rings Cormorants. LIMOSA 57 (3): 119-119.

Since 1978 breeding cormorants in the spontaneous stored willow trees along the Knardijk in the Oostvaardersplassen. The size of the colony amounted to 1983 than 4000 breeding pairs. This strong growth is not due to relocation of birds from the Naardermeer but is an independent development parallel to increasing numbers of breeding pairs in Denmark, Sweden, Poland and GDR. To understand

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