Florian Melles lends a hand again. He has already installed several nesting aids for ospreys and knows his way around. (Roland Scheitz)
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It is still on the ground, the approximately 20 kilogram platform made of weather-resistant metal. In order to mount it high up on the power pole, the Wesernetz workers have to use a special climbing technique to get to a height of 45 meters.
This artificial eyrie is intended to convince the shy bird of prey of the advantages of the Ochtumniederung nature reserve near Brockhuchting. He can be seen every now and then, but he doesn’t like to brood. And that has been the case for more than 100 years.
Plenty of food for the osprey
“We have seen ospreys flying in the area over and over again in recent years,” says Birgit Olbrich from BUND Bremen, “and in the shallow water zones of the Ochtum with several ponds nearby, he apparently finds plenty of food.” As the name suggests, nourishes This type of eagle is almost exclusively from fish, which it catches in a rapid swoop and holds onto it with its sharp claws.
“Ospreys overwinter in areas south of the Sahara and, when they return to Central Europe, look for suitable nests to breed by the end of March,” says Florian Melles, who is a project manager in the field of nature conservation at Hanseatische Naturentwicklung and has already installed several nesting aids for ospreys.
“The bird actually looks for tall, isolated trees with flat crowns in the landscape for breeding – but these rarely exist in nature,” says Florian Melles. That is why almost all of the currently around 20 breeding pairs of ospreys in Lower Saxony breed on artificial clumps, usually on electricity pylons.
What the insecticide DDT can do
“The species that is sensitive to traffic and leisure activities needs a wide all-round view of around 300 to 500 meters and would therefore never breed in the forest,” says Florian Melles, “and being close to the water that provides it with food is a must . “Due to hunting, but especially due to the insecticide DDT, the osprey has declined extremely. The environmental toxin made the eggshells of many other species of birds of prey, which are at the end of the food chain, so thin that they were not successful in breeding. The species only survived in northeast Germany.
When the environmental toxin was banned in the GDR at the end of the 1970s, the numbers of the elegant bird of prey recovered. Artificial nesting platforms were installed on poles and trees by conservationists. The osprey returned to Lower Saxony from the eastern federal states in 1991.
The specialists from Wesernetz are ready to transport the platform to the eyrie. But because of the heavy rains in the past few days, they have to postpone construction. “The power pole for the eyrie is currently deep in the water, it is impossible to get there dry,” says Birgit Olbrich.
Breeding aid with perches
When the water has drained again, the platform, on which two perches are attached, is screwed down, and a few twigs are placed on the artificial nest to encourage circling ospreys to land and later to breed.
The cost of the nesting platform, a custom-made product from the Bremen company Baum Haus Bau, is borne by the Bremen nature conservation authority, while the Wesernetz is responsible for assembly and maintenance. Birgit Olbrich from BUND does not see the danger that a white stork could use the nesting offer instead of the eagle. “The platform is far too high for that. And if it were so, we would of course let the stork have it, ”she says.
Osprey breeds in Nienburg on the Weser
The chances that an osprey will breed again in Bremen are not bad. Because the species is currently spreading further west in Lower Saxony and is already breeding in Nienburg an der Weser. The successful settlement in Lower Saxony so far and the good framework conditions in the Bremen protected areas give hope. Because in the area of a few hundred meters around the platform there is no leisure activity or regular traffic – these are requirements that must be met, especially during the breeding season and the rearing phase between April and June.
Birgit Olbrich, initiator of the project, is confident: “Now the art nest only has to be discovered and used by a pair of ospreys,” she says. The further development is followed and documented through the regular breeding bird observations as part of the Bremen protected area management.
Down to business
Observation tip
In the Ochtumniederung nature reserve near Brockhuchting, the osprey could easily be observed with binoculars on its prey flights if it accepted the eyrie in the future. The medium-sized eagle is easy to recognize by its slender body, long, narrow wings and, above all, its bright white underside. A dark eye stripe runs through the white head – this plumage and the more seagull-like flight clearly distinguish the osprey from other birds of prey.
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