Species protection plans for birds: trends in numbers
Species protection plans have been drawn up for the spoonbill, Montagu's harrier, barn owl, little owl, partridge and black grouse. Since 1990 the spoonbill and barn owl have been increasing, the Montagu's harrier has been more or less stable, and the partridge, black grouse and little owl have been declining.
Trends in the spoonbill
At the end of the 19th century there were over 1000 pairs of spoonbills breeding in the Netherlands, but in the 1960s the population declined to 150 pairs, as a result of PCB poisoning. There has been a steady recovery since the 1980s. After 1987 the colonies in Lake Naarder and Zwanenwater were disturbed by predatory foxes. Beeding pair numbers more than recovered, however, after the spoonbills moved to new breeding areas in the Oostvaardersplassen and on the Wadden islands.
The 1994 species protection plan aims to ensure the sustainable survival of the spoonbill in the Netherlands. To achieve this the population must have increased to about 1000 breeding pairs by 2010. This target was met as early as 1997, when 1138 pairs nested. Another aim is for the number of nesting areas to increase to 15-20. Though the number of such areas has grown, in some areas there are only one or two breeding pairs.
Trends in the Montagu's harrier
At the start of the 20th century there were an estimated 500 breeding pairs at least of the Montagu's harrier, but because of intensive agriculture by the 1980s only a few remained. In the 1990s the setting aside of fields in east Groningen in response to EU policy allowed the Montagu's harrier to recover to about 30 breeding pairs. Most of the Dutch population of the species are found in the fields of east Groningen, particularly in fields of lucerne. The 2000 species protection plan aims to achieve an increase in the number of breeding pairs that results in a sustainable population. The target is about 60 breeding pairs in peak years.
Trends in the barn owl
Since falling to less than 100 breeding pairs in 1963 the barn owl has recovered strongly. It has made even more progress since the species protection plan appeared in 1996. The barn owl has profited greatly from the owl nesting boxes hung up by volunteers, and from a series of mild winters in recent years. There are currently about 2000 breeding pairs; in 2001 there were even over 2400.
Trends in the little owl
Little owls are declining sharply in the Netherlands because of a loss of nesting sites such as traditional orchards, pollarded willows and old barns, and a loss of hunting area as a result of the intensification of farming. Since 1970 the number of little owls has halved; the decline is continuing. Distribution data from SOVON show that the little owl has declined most in the three northern provinces and in the west of the country. The species protection plan aims to have 12 000 breeding pairs (Plantinga, 1999). The current number is circa 5500-6500.
Trends in the partridge
Partridges have been declining nationwide since the 1950s, and since 1960 have declined by 90%. The most important reasons for the decline are the use of agricultural pesticides, the upscaling of agriculture, the purification of seed, crop breeding, and the rise in maize cultivation. The 1991 species protection plan aimed to maintain the arable habitat, in which the partridge was used as an indicator. However, the plan has not halted the decline of the species.
Trends in black grouse
The black grouse was very numerous in the 19th century because of the flourishing buckwheat cropping on wet heathland and on bog peat. But numbers fell dramatically in the 20th century: in 1941 there were estimated to be 5000-6000 cocks in the Netherlands, but by 2001 there were only 14. The reasons for this decline are the decrease in the area of heathland and the encroachment of grass in the remaining heaths. The lack of suitable arable fields near the heathland makes it difficult for chicks to survive. And the species may also be suffering from inbreeding. The 1991 species protection plan has not halted the decline.
Al l these species are on the Red List of birds.
