German Federal Agency for Nature Conservation (BfN)

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Vilm im Jahresverlauf

Strong westerly winds…

... led to the arrival of Eider (Somateria mollissima) as well as some really rare visitors on Isle of Vilm or Lauterbach Harbor:
At the BfN-Pier in Lauterbach the sad discovery of a dead Leach's Storm Petrel (or Leach's Petrel, Oceanodroma leucorhoa) was made on the 30th of November 2011. The species spends almost its entire life airborne on the sea and really only returns to land for breeding. The species ranges are mainly the marine areas of the Northern Hemisphere with breeding colonies mostly on small remote islands. These birds very rarely have been documented along the German North Sea coast and are even rarer along the southern Baltic Sea coast. Sadly enough, most birds found or documented in these areas have a poor fitness and many die. Being dislocated by the storm, the small birds now have too little wind and hence use up too much energy for finding food and staying airborne.


Dead Leach's Storm Petrel (found at the BfN Pier in Lauterbach Harbor on the 30th of November 2011)
Dead Leach's Storm Petrel (found at the BfN Pier in Lauterbach Harbor on the 30th of November 2011)

Isle of Vilm - icebound

Winter came rather late this year. But then temperatures dropped as far as - 20°C and even further. Starting in early February, the Isle of Vilm was completely surrounded by thick sea ice and it was only because of the icebreaking MS Petersdorf that the Agency could continue to work. The "warm" water in the open shipping channel was steaming...

Steaming “warm” waters in the open shipping channel to Isle of Vilm (Isle of Vilm, Winter 2012)
Steaming “warm” waters in the open shipping channel to Isle of Vilm (Isle of Vilm, Winter 2012)

Looking at the white scenery in sunshine makes the land- and snowscape far less cold and barren. The vast ice cover of the Greifswald Lagoons is again always an impressive sight.

“Snowscape” on Isle of Vilm (Isle of Vilm, Winter 2012)
“Snowscape” on Isle of Vilm (Isle of Vilm, Winter 2012)

Snow, ice and low temperatures brought even more hardship to local bird life which already had to cope with little available food. However, some species, like the White Tailed Eagle, seem to profit: Many migratory ducks, geese and swans are in poor shape or have already died and the big raptor can easily hunt and feed on them.

Astoundingly enough also a Great Grey Shrike (Lanius excubitor) withstood the harsh conditions seemingly unimpressed (well, changing mimics is not one of the bird’s main talents, anyway). The songbird who feeds on larger invertebrates and small vertebrates like mice or lizards for most of the year, never seemed to have trouble finding food – despite of the snow cover: It was regularly observed hunting smaller songbirds. The following image documents the imprint of the shrike in the snow after it had caught a Great Tit (Parus major). The shrike was seen chasing the tit around the bushes just seconds before the shrike finally stroke its prey. 

 

The imprint in the snow was left behind by a Great Grey Shrike and a Great Tit – the later one just being hunted and killed by the shrike (Isle of Vilm, Winter 2012)
The imprint in the snow was left behind by a Great Grey Shrike and a Great Tit – the later one just being hunted and killed by the shrike (Isle of Vilm, Winter 2012)

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