Île aux oiseaux (Préverenges)

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Île aux oiseaux (Préverenges)
île aux oiseaux in summer
île aux oiseaux in summer
Waters Lake Geneva
Geographical location 530642  /  151033 coordinates: 46 ° 30 '25.2 "  N , 6 ° 32' 6"  O ; CH1903:  530642  /  151033
Île aux oiseaux (Préverenges) (Canton of Vaud)
Île aux oiseaux (Préverenges)
length 190 m
width 20 m
surface 0.21 ha

The île aux oiseaux ("bird island") is a raised, artificial island in Lake Geneva . It is located on the north shore of the lake near the mouth of the Venoge in the municipality of Préverenges . It surrounds a sheltered shallow water area from which a smaller island protrudes and serves as a resting place for migratory birds that use Lake Geneva and especially the Veno estuary as a stopover. However, due to the disappearance of natural riverside areas, they can hardly find any food and are often disturbed by walkers. The artificial island should give them a place to stay instead of the natural shore areas. After several years of planning, the island was laid out in 2001 and 2002. In the first year of its existence, the number of migratory birds observed in Préverenges increased significantly.

geography

The île aux oiseaux is located on the north shore of Lake Geneva in the area of ​​the municipality of Préverenges, about 300 meters west of the mouth of the Venoge. It consists of a 2100 m², crescent-shaped island, which is in front of the shore in a few meters deep water and protects an area of ​​around 1.5 hectares from wind and waves. The island was made from various materials. At high tide, the highest point on the island is about 1.2 meters, while only a smaller island, about 160 m² in size, is above water. When the water is low, additional areas are above water and provide food for the birds.

The island and the area enclosed by it are under special protection. Entering the island or swimming is prohibited. Dogs must be kept on a leash on the adjacent bank.

Planning and construction

The construction of the île aux oiseaux was preceded by several years of studying migratory birds at the mouth of the Veno. In 1986 a first sketch of the project was rejected by the Center de Conservation de la faune et de la nature . It was feared that the island might affect the appearance of the shore. In 1995, another project was presented to the Office fédéral de l'environnement, des forêts et du paysage (Federal Office for the Environment, Forests and Agriculture, now the Federal Office for the Environment ), which provided for information boards on the shore and an artificial island. This project was subsidized with around 60,000 francs, the information boards were set up in 1996, and in 1997 the île aux oiseaux project was presented in the magazine Nos Oiseaux .

Between April and May, L. Maumary made a film about migratory birds in the municipality of Préverenges to raise public awareness of the issue. The film was then shown at community meetings in the surrounding communities. In 1999, surveying began and in December 2000, the project received planning permission . The construction of the island lasted until 2002.

A total of 3750 m² of material was poured, mostly sand and gravel from the Venoge river bed and a French quarry. The construction was financed mainly by funds from various foundations and environmental organizations (around 500,000 francs), and in part by public funds (around 60,000 francs). The construction costs of around 530,000 francs were offset by income of 570,000 francs. The unused funds were used for additional information boards, buoys and any maintenance work.

Flora and fauna

île aux oiseaux seen from the shore

The island, consisting mainly of the sand of the Venoge River, was quickly colonized by plants after completion. Around 100 different species were observed as early as 2002. After a year, annual pioneer plants dominated , which can also be found on the roadsides, such as dandelions or nettles . Blackberry bushes were also already there, they have been removed regularly since then so that they do not completely overgrow the island. Today both islands are completely overgrown with grass , and smaller trees have also settled on the larger island.

Even before its final completion at the end of 2002, numerous water birds were sighted on the island, between April and June alone 14 species of gulls and 27 different species of wading birds . The total number of birds observed was around 1500 in 2002. Such a number was previously only observed in years with low water levels. Since the water level of Lake Geneva is regulated downwards by around 30 cm every four years in order to enable the shoreline to be cleaned, waterfowl have larger, shallow or water-free coastal areas at their disposal in these years; in contrast, there were even more birds in 2002 than in the low water years of 1992, 1996 and 2000. The île aux oiseaux therefore seems to serve its purpose as a resting place for migratory birds. By 2016, over 210 different bird species had been observed, including rare species such as sandpiper , common loon and little egret .

Web links

Individual evidence

  1. a b c d e Final report of the Île aux Oiseaux group after completion of the island. (PDF; 771 kB) Groupe “Île aux oiseaux”, January 2003, accessed on September 12, 2016 .
  2. a b Lionel Maumary, Laurent Vallotton, Michel Baudraz: Construction d'une île aux Oiseaux à Préverenges: un nouveau site d'escale pour les limicoles migrateurs. In: Nos Oiseaux. 50, 2003, pp. 59-64.
  3. The Swiss Ornithological Institute lists 422 different bird species for the entire Swiss territory, meaning that around half of all Swiss bird species find a temporary refuge on the île des oiseaux.
  4. Île aux oiseaux on the Birdline Suisse website. Birdline Internet, accessed September 26, 2016 .