The osprey, Pandion haliaetus, in Schleswig-Holstein and Hamburg

Abstract

The Scandinavian countries (and Mecklenburg) are possible areas of origin for the osprey, Pandion haliaetus, which migrates through Schleswig-Holstein and Hamburg. After the war, there was a welcome increase in the population there. In recent years, there has been a sharp decline in the birth rate. This may be reflected in a reduction in migration numbers for 1965 and 1966 in our region.

The small number of Norwegian birds probably migrate south along the North Sea coast. Swedish birds in particular migrate via Fehmarn and through East Schleswig-Holstein and Hamburg. 70% of all migrants are recorded in this area. This part of the country is particularly rich in water, but only about 10% of the eagles rest for more than a day. Many migrate without stopping. There is no discernible preference for fish farming waters.

769 observations from Schleswig-Holstein and Hamburg from 1947 to 1966 yielded 886 specimens. These are predominantly individual observations. On average, 40 specimens are seen in autumn, fewer in 1965 and 1966. Resting and migration density: In 20 years, only once were ospreys seen at 5 points simultaneously (6 specimens in total), 7 times at 4 points. Highest migration numbers per day at good locations (Fehmarn) 5 specimens, only once 15 specimens. The proportion of ospreys in the migration of birds of prey is about 1/1000, with resting numbers at a body of water in very rare cases up to 5-6 specimens.

Return migration from mid-March to late May, peaking with one-third of migrants arriving in the first ten days of April. Departure from early August to early November, peaking in the first half of September.

There are a total of 57 records of summer occurrences, 23 of which are from Lake Warder (East Holstein) alone. The main occurrences are in three areas in the east and south-east of Schleswig-Holstein. No breeding has been documented. It is likely that some of the summer birds are two-year-olds that are not yet capable of breeding. These can certainly be regarded as potential breeding birds of tomorrow.

Winter observations are increasing, but there is no real wintering. Some of these may be injured birds.

There are 5 known ring finds of Swedish birds, including a two-year-old summer visitor.

Even recently, migrating ospreys have been killed in Schleswig-Holstein. In autumn 1966, there were 16 observed specimens in the entire area, compared to 9 shot down!