Passage 2
The largest of the world’s 17 penguin species, emperor penguins stand
nearly four feet and weigh up to 90 pounds. These sea birds never set
foot on dry land. (1) An estimated 200,000 breeding pairs live in about
40 penguin colonies scattered along the coasts of Antarctica. (2) Their
waterproofed feathers, flipper-like wings, and streamlined bodies make
them excellent swimmers and divers. On ice they can travel distances
up to 50 miles by “tobogganing”—gliding on their stomachs while
pushing with their wings and feet.
(3) Emperor penguins breed during the Antarctic winter in some
of the world’s most severe weather conditions (temperatures of –80 F
and winds up to 112 miles per hour). Breeding during the winter
allows chicks to mature in midsummer when food is plentiful. After the
female lays a single egg, the male holds it in a fold of skin near his feet
for a two-month incubation period.
During this time he huddles with other males to keep warm.
(4) The male moves very little and does not eat, usually losing up to a third of his body weight.
Meanwhile the females go to sea and dive for fish so that when
they return they can feed and care for the newly hatched chicks.
After the male restores his body weight, both parents take turns caring
for their young.
The world’s emperor penguin population declined in the last 50 years
due to a period of warming ocean temperatures. Warm water shrinks
ice cover and reduces the population of krill—a small crustacean that
is the emperor penguin’s staple food. Today the emperor penguin population
has stabilized, but warming trends could again threaten this magnificent
sea bird.
The passage suggests that