a question. elizabeth club from cologne wants to know why do migrating birds call to each other during their flight doesn't that cost them too much energy. every autumn there is frenzied activity at the gathering in resting places these cranes coming from northern europe have thousands of kilometers still to go before they reach their winter quarters wild geese also head to warmer climes in the winter when they begin their long journey they all honk loudly this vocalization is an important form of communication. much communication between animals goes on heard by humans elephants exchange signals in the infrasound part of the sound spectrum the tones are so low frequency that our ears can't pick them up. manta rays send acoustic messages underwater by