Alpine newt
After a steep decrease in the alpine newt population in the 1960s-70s, they have recovered their numbers a bit. Surveillance in the surrounding area of Cologne (approximately 50m above sea level) showed an increase in alpine newt numbers, but the numbers of newts in breeding pools seemed to decline. In home gardens, newts are settling in pools in which there may be a high reproduction rate. If fish are in these ponds, the population will be completely wiped out. However, a small pool of 150 litres volume had more than 60 alpine newt tadpoles of different sizes at the beginning of July 2003. They were likely spawned from just one female.