:43:00
in deep waters, locating
:43:02
pursuing and catching prey
is exceptionally difficult
:43:06
but duskys have developed
some extraordinary tactics
:43:10
in the morning, small
search parties set out
:43:13
probing with their sonar
:43:20
there may be twenty to thirty
groups patrolling these waters
:43:23
each pod separated
by a mile or two
:43:28
the leaps give them a vantage
point for sighting prey
:43:38
seabirds have gathered up ahead
a sign they've found something
:43:48
this time of year southern
anchovies are here in vast numbers
:43:53
for the penguins
it's a feast
:44:01
it's up to the dolphins
to bring some
:44:03
order to all this and
they quickly do
:44:06
the dolphin's strategy is to
circle the school
:44:09
and drive it into an
ever tightening ball
:44:12
they guard the outside
perimeter by blowing bubbles
:44:15
which frightens the fish
:44:18
this takes advantage of
the fishes' natural defense
:44:21
to huddle together
when attacked
:44:24
as the fish ball
gets tighter
:44:26
the duskys take turns
grabbing mouthfuls
:44:29
of fish then retreat
to guard the perimeter
:44:50
soon the ball is
clustered so tightly
:44:53
the fishes' escape
response breaks down
:44:56
now it's simply a
matter of the
:44:58
dolphins' nipping food
off the edges