BOB HIRSHON (host):
How narwhals flee danger. I’m Bob Hirshon and this is Science Update.
When faced with danger, some animals’ heartrates shoot up as they either fight or flee. Others freeze and their heartrates drop. But narwhals, small whales with a single tusk resembling that of the legendary unicorn, paradoxically do a little of both. This according to UC Santa Cruz ecophysiologist Terrie Williams. Her team reports in the journal Science that when escaping from hunters’ nets, the deep-diving whales rapidly fled, while simultaneously slowing their heartrate to a near standstill, as if freezing from fear.
TERRIE WILLIAMS (UC Santa Cruz):
There’s about 15 to 20 seconds between every beat of the heart. And that’s a long time. But the narwhal was swimming as hard as it could.
Williams says this unusual response may make the whales particularly vulnerable to recent human disturbances to their Arctic home. I’m Bob Hirshon, for AAAS, the science society.
Story by Susanne Bard