Can we use vocalization frequency to predict elephant age?

Can we use vocalization frequency to predict elephant age?

Background: Elephants are intelligent animals that rely on family groups for protection and support. They can communicate over long distances with low-pitch vocalizations. In 2014 a group of scientists wanted to know if they could identify elephants’ ages based on the pitch of their vocalizations.

The graph shows the frequencies of vocalizations recorded by individuals of a known age group.

Data Source: http://pages.vassar.edu/sensoryecology/stoeger-hears-a-who-age-range-est...

Questions: 

1.  Describe what the graph shows about how similar or different the vocalizations of the four age groups are.

2. I interpret this graph to mean…

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