De stand van de Ooievaar, Ciconia c. ciconia (Linné), in Nederland in 1956 (The Status of the White Stork in the Netherlands in the Year 1956)

The result is given of a complete census of the breeding population of the White Stork (Ciconia ciconia) in the Netherlands, performed during the year 1956. The results of the census of 1950 and 1955 have been published in Beaufortia 5 (45), April 15, 1955: 23—42, and 5 (52), March 24, 1956: 101—115. The result of the census 1956 shows a less alarming picture than that of 1955. The number of nests occupied by pairs increased to 65 (57 in 1955)¹). The number of young fledged increased to 95 (94). However, three newly fledged young perished in the neighbourhood of their nests, so that the ultimate breeding result of the species in 1956 is somewhat less than in 1955. The number of nests on which breeding occurred was higher than in 1955. From 65 (57) nests occupied by a pair of birds breeding occurred in 44 (36) cases. The very unfavourable weather might have influenced the relatively bad results. The storks arrived considerably later than in other years. Nevertheless the sharp decrease which could be observed after 1950 seems to have come to a stop. The White Stork in the Netherlands lives at the border of its breeding area and population fluctuations have to be considered in this connection as far as even expecting the vanishing of the species from the Netherlands fauna at all. Everything is done at present to prevent the loss of the White Stork from this country. The Netherlands Society for the Protection of Birds has started an action for erecting new nesting sites. Well-known investigations in Bavaria have shown the density of the population to increase by this way. It has yielded some results in the Netherlands too. Six new nests have been occupied by pairs or solitary birds and on two of these nests young have been raised of which 7 fledged. In the present paper all nests are renumbered and the numbers of the 1950 census are given in parentheses. Where this number is failing the nest has been occupied after 1950 or 1955. Nests marked by + were occupied by a pair of birds but no young birds were raised. The number of young storks fledged is indicated by a figure. A summary of the results and a comparison with 1950 and 1955 is given in the tables 9, 10, and 11. The number of eggs and young storks which got lost by fighting on the nests and the number of nesting sites lost since 1950 are given on page 192.