Biology
Development of Song Learning and Critical Periods in Zebra Finches
Quick fact
Zebra finches must learn their song during a critical period that closes around day 90; if they are deafened or isolated before this, they develop an abnormal, simple song that they cannot later correct.
Why this is interesting
A young zebra finch hears its father's song for only a few weeks, yet months later it can produce a nearly exact copy. How does a brief exposure early in life leave such a lasting mark?