The
Discovery of Biosonar:
1. Spallanzani and Jurine
Spallanzani resorted
to blinding the bats with hot wires, and even
removed the eyes completely. These methods were
considered inhumane even in his day. However,
when the bats had recovered from the distress
of the operation, they behaved just like intact
bats. Their obstacle avoidance capabilities
were just as good. They remained nimble and
agile. Spallanzani noted they still sensed their
environment very accurately: they would fly
past smooth stones in the walls and ceiling
and choose rough ones which provided enough
grip to hang from. These
blinded bats, once released, would even return
from a night's hunting with their bellies full
of insects!
time line
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