"We now know that the larger the whale's head is, the longer its clicks will be," Thode said. The firecracker analogy might not be too far off, since he explained the huge rectangular-shaped top of the sperm whale's head contains the spermaceti organ, which produces a white, waxy substance formerly used by humans to make candles and ointments. In this case, it facilitates the movement of sound that "ricochets back and forth within the whale's head, knocking against the skull." The researchers detected several "mini clicks" within each audible whale click, all of which are part of the marine mammal's echolocation system. The produced sound bounces off of objects, such as the cod, and returns as an echo back to the whale, permitting him to determine the cod's size and location. Since each whale appears to have its own unique clicks and vocalizations, Thode believes it will soon be possible to record whales underwater and tease apart their sounds. Researchers might then more accurately count whale populations, which could improve conservation efforts and help to prevent future whale and longline encounters that can be dangerous for both the toothed whales and fishermen. In a separate study, University of California's David Lindberg and his colleagues determined that sperm whales evolved their elaborate echolocation methods in order to "develop a complex system with finer resolution to detect and capture soft-bodied squid." Some giant squid can grow to lengths of 40 feet, providing a hard-to-resist treat, not unlike the longline dangling black cod seen in the new video. "Some of my friends think the video looks like a fake shadow puppet show," Thode said, "but I assure everyone it's real." Related Links: |
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