Different bat species can be observed in summer in Nuremberg's old town just above the water surface while they are hunting insects.
Many bridges could provide additional quarters for bats easily. Under the Bridges bat brick roosts could be mounted during bridge maintenance works.
A plus for more urban nature and the old town would be enriched by a small but effective attractions.
Image sources (left to right):
1, Nürnberg at night: hogr
2 and 3, bat, finger: green pacifier
4, brick roost: Schwegler