Read the passage and answer the
questions that follow.
Every winter, hundreds of humpback whales migrate
long distances from their high latitude feeding
grounds in the Arctic and Antarctic to warmer
tropical regions to breed and give birth. The
newborn calves, which drink over 52 gallons of
milk every day, have only a few months to gain the
body fat needed to keep swimming back to cooler
waters in summer. How the babies signal hunger
and avoid predators during these early months has
always been a mystery to scientists.
"We know next to nothing about the early life
stages of whales in the wild, but they are important
for the calves' survival during the long migration to
their feeding grounds," says study lead author
Simone Videsen of the University of Aarhus,
Denmark. "These early life stages of wild whales
are so confusing because they're an aquatic animal.
We can't follow them around all the time to see
what they're doing."
Studies revealed that instead of crying loudly like
their human counterparts, humpback calves signal
their hunger by gently nudging their mothers or
uttering soft grunts and squeaks. The moms answer
the requests by responding with quiet calls.
The team believes these quiet conversations help
whale mother keep track of their young in murky
waters without being overheard by dangerous
threats. According to Videsen, "Potential predators,
such as killer whales could listen to their
conversations and use that as a clue to locate the
calf and attack on it."
The scientists think that the low audible
conversation also keeps mate-seeking males at bay,
allowing the females to focus on nurturing the
newborns before the tough, 5,000-mile journey back
to the feeding grounds in the Antarctic.
The humpback whales migrate from Arctic and
Antarctic to tropical regions every winter because
the __________.
A. weather is much cooler there
B. calves need 52 gallons of milk
C. warm weather there is ideal for breeding and giving birth