Inventarisatie van de Fuut in 1983

In 1983 the number of breeding pairs of the Great Crested Grebe (Podiceps cristatus L.) was counted by at least 250 observers in the Netherlands. About 50% of all the potentional breeding habitats and locations were investigated. From at least 700 Atlas-squares (5x5km²), in wich breeding populations of the Great Crested Grebe occur, observers counted in 424 squares more of less. The inquiry gives opproximately 4900 breeding pairs. The density of the number pro Atlas-square is not always the same, but for the Netherlands an average of 11.5 was found. Taking into account the incomplete counting, the real number was estimated by extrapolation on 6900-7600 breeding pairs. In 1966-1967 were that 3600-3800 and in 1975-1976 5000-5400 breeding pairs. It looks the numbers will be still increasing or at least stabilisize in spite of the continuing waterrecreation and water pollution. Great Crested Grebes often breed in colonies. At least 30 locations were observed with about 5 up till more as 150 nests close together. Solitary breeding in canals etc. in towns became more common. In at least 25 towns this fenomenon was observed now. Many observers noticed data of foraging flights from places with few or no fish to places with sufficient food. Finally large groups (concentrations) of moulting Great Crested Grebes can be observed especially on several lakes f.i. ’IJsselmeer’ and they number up to 4000-7000 individuals in August and September. In spring, summer and winter mostly smaller groups are occurring.