Why whales learned to become silent killers

[Mr T.]

Why whales learned to become silent killers
By Roger Highfield, Science Editor
(Filed: 14/12/2004)

Killer whales use military-style stealth tactics when hunting seals and other mammals, scientists reported yesterday.

Just as stealth bombers sparingly use highly focused radar to avoid detection, so whales shape the use of their calls so as not to warn off victims. Researchers at the University of St Andrews in Scotland and the University of British Columbia in Canada, made the discovery, to be reported in the journal Animal Behaviour, by studying two forms of killer whale – residents and transients.

They found that fish-eating residents are more likely to talk to each other while mammal-eating transient killer whales travel and hunt silently, only interrupting the underwater blackout for brief bouts of communication after a kill or when exhibiting surface behaviour such as flipper slaps or dolphin leaps.

The reason the residents are so talkative is that fish are hard of hearing and cannot detect the calls at any distance. But underwater mammals have excellent hearing, allowing them to "eavesdrop" on the transients' calls and escape.

Animal Behaviour

Killer Whale Sounds - University of British Colombia

Whale Communication Research - Cornell

[Allan Carr]

Amazing creatures. We did a whale watching trip whilst in British Columbia and it was led by a marine zoologist from the University of BC. Learnt a huge amount about Orca's. Never realised just how fascinating they were.

[Paul Beal]

I wish I was involved in the research into that one! I don't hate my job but some scientists get far more attractive things to work on than most!

Paul