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Episode Transcript

Speaker 1 (00:00):
Why do elephants have enormous ears? Welcome to Science News,
where we explore the fascinating science behind the natural world. Today,
we're focusing on one of the most recognizable features of
the African elephant, its massive ears. The African elephant Loxodonta africanum,
is not only the largest land mammal on Earth, but

(00:20):
it also has the largest ears of any living elephant species.
In fact, their ears can account for up to twenty
percent of their total body surface area. While these ears
are undeniably impressive, they serve a far more important purpose
than just helping elephants here. The unique shape and size
of these ears are vital to the elephant's ability to

(00:41):
survive in the often scorching environments it inhabits. African elephants
are known to rome vast distances, often covering up to
twenty five kilometers per day. On some occasions, they can
travel as far as one hundred and ninety kilometers. These
long journeys take them through a wide range of environments,
from tall grasslands to dense forests, but the hottest and

(01:03):
most challenging regions are deserts and dry savannas. In these
hot climates, where temperatures can easily soar well above forty
degrees celsius. Elephants need an efficient way to regulate their
body temperature. Their bodies are adapted to maintain an optimal
temperature of around thirty six degrees celsius, but this can
be difficult in extreme heat. This is where their enormous

(01:25):
ears come into play. The structure of the elephant's ears
allows them to dissipate heat. The ears are made up
of a thin layer of skin with a dense network
of blood vessels just beneath the surface. As blood circulates
through these vessels, the heat from the body is transferred
to the ears, where it can then be released into
the air. This cooling process is so effective that an

(01:48):
elephant can circulate up to twelve liters of blood through
its ears every minute. This allows them to maintain their
body temperature in the intense heat they often face in
the wild. Interestingly, the mechanism behind the large ears of
elephants is quite similar to the smaller ears of other
animals adapted to extreme temperatures. For example, polar bears have

(02:09):
relatively small ears, which help them retain heat in the
frigid Arctic environment. The polar bear's ears are a key
adaptation to their cold habitat, while the elephants oversized ears
serve the opposite function, helping them stay cool in the heat.
These contrasting adaptations show the incredible ways animals evolve to
thrive in their respective environments. However, African elephants aren't the

(02:34):
species with the largest ears relative to their body size.
That distinction belongs to the long eared jerboi eukarats naso,
a small rodent found in the deserts of Mongolia and
northwest China. These desert dwellers have ears that are more
than one third the size of their heads, which helps
them keep cool in the searing desert heat. Much like

(02:54):
the African elephant, the jerboa's oversized ears are just one
of the many fascinating adaptives it has developed to survive
in one of the hottest environments on Earth. The jerbo
also has kangaroo like legs, which it uses to hop
across the desert in search of food and water. So
the next time you see an elephant flapping its giant ears,

(03:15):
remember that it's not just a charming gesture, it's an
essential survival strategy that helps these majestic animals thrive in
some of the most challenging environments on Earth. Thanks for
tuning into science News, Stay curious, and we'll be back
soon with more exciting scientific insights.