:34:16
with its own
sonar turned off
:34:18
a killer whale moves silently
through alaskan waters - listening
:34:25
it can hear the
slightest splashing
:34:27
the very breathing
of distant prey
:34:38
a group of dall's porpoises
just up ahead
:34:44
these are among the fastest
small cetaceans
:34:47
so quick and agile they can
elude most predators
:34:55
they travel these icy waters
in groups of two to ten
:35:00
but for this small herd there's
little safety in numbers
:35:07
as quietly as possible
:35:09
the killer whales
are closing in
:35:11
the slightest sound would
betray their presence
:35:22
the porpoises
detect something
:35:26
but it may be too late
:35:28
the killers are capable of
speeds up to thirty miles per hour
:35:41
the porpoise zig-zags
for its life
:35:50
killer whales are masters at
cutting off the path of retreat
:35:57
this one dives below
a harbor porpoise