With a "Vuchelheisle" to America

This picture is taken from the German edition of the National Geographic (April 2000, p. 202).

Following explanation is given:

This photo shows the arrival of canaries from St. Andreasberg (Hartz Mountains) at a harbour somewhere in the USA in 1928. The cages are made of wood. They are called "Vuchelheisle". That's the slang of the miners of the Hartz Mountain area and  means "bird house". There were only males in that cages. In the year 1883 C. Reiche from Alfeld shipped about 120000 male Hartz Mountain Rollers to New York.