'Vonder Vogel'...

It seems that "Vonder Vogel" is referred to more correctly as ...von der 'Vogel-Partei'.

Also, has something to do with the 'Spreewald' historically. The Spreewald is a vacation community & nature preserve outside Berlin. During WWII was the site of one of Hitler's intelligence agencies. After the war, the base was flooded and is now a lake.
Because the area has many lakes and rivers, this area also saw the use of U-boats. I do not know for what purpose though.