NARRATOR: The
migrating humpbacks
have only one objective now,
the safe house of Mozambique.
It's a whale-birthing paradise
far from the usual hunting
grounds of great white sharks.
Vulnerable baby whales can
nurse, grow, and gain strength.
The adults have traveled
4,000 miles to safety.
The warm water and
lack of predators
give their species the
best chance of survival.
[whale singing]
It's a magical time.
The whales spend up
to four months mating,
birthing, and
nursing their young.
[soothing music]
This is their time
to bond and interact.
But these adult whales
have not eaten since they
left Antarctica months ago.
Their strength
diminishes each day,
and the time is coming when
all of the adults and calves
will have to swim the 4,000
miles back to Antarctica
to feed.
Now, after four
months up in Mozambique,
they start this
return migration down,
and that's when it's going
to get really interesting.
Because at that
stage, you're going
to have these weak whales,
these whales that haven't fed
up enough that have been starved
for the last four or five
months.
And as they go
down, they're going
to be the ones that,
I think, are really
vulnerable to attack by sharks.
