vocal Plasticity



Australian fur seals

Australian fur seals show vocal plasticity in their calls.  For instance the barks produced by males are faster when they are involved in confrontations and slower when males are stationary and advertising their territorial status. 

Blue Whales

Over the last 50 years blue whales worldwide have changed the way they are singing. Calls are progressively getting lower in frequency.  This holds true for the Australian pygmy blue whales that are decreasing their call frequency at a 
mean rate estimated to be 0.35 Hz/year over the nine year study. This was based on the frequency of the third harmonic of the second call unit.