According to current understanding, there are two reasons for whales to emit sounds; to locate objects and to communicate. Whales rumble, grunt, and gurgle using their voices to attract mates, stay in touch with their offspring, and navigate the shelves, seamounts, and islands in the ocean. Humpback whales also show evidence of cultural transmission. In any year, whales sing identical songs in Hawaii and Mexico, breeding areas that are 4,500 kilometers (2,800 miles) apart. Perhaps they hear the songs across long distances or learn them during the summer months, when different groups gather in the north to feed. More remarkable than the geographic consistency is the change in calls over time. Slight variations in the songs occur each year. But, as with evolution, these changes can make huge leaps in a short time.
Scientists have been studying humpback whale songs for nearly fifty years, but there are strange things about them we still can’t explain: Only the male whales sing these amazing songs, so it is generally assumed that the song is to attract the attention of females. However, no one has ever seen a female whale approach a singing male. Instead, other males seem to be more interested. When they approach the singer, he stops singing, and the two males go off silently together for a little while, and then they separate.
Now, studying humpbacks with new methods, Cholewiak, a researcher with the Stellwagen Bank National Marine Sanctuary, has uncovered the first known instances of what looks like whales responding musically to each other’s songs. Read the full article at Discovery News.
Copyright © 2009 by Marine Science Today, a publication of OceanLines LLC