National Geographic UK - 10.2019

Workers load a West

African giraffe into

a trailer. Later it will

be moved 500 miles

to Niger’s northeast

Gadabedji Biosphere

Reserve to help grow

a new population of

the subspecies, which

has about 600 animals.

The giraffe has the highest known blood

pressure of any animal, and yet somehow it can

manage to quickly drop its head 16 or 17 feet to

the ground without passing out. Because it’s

so difficult for them to get up and down, and

because they’re so vulnerable when they’re on

the ground, giraffes only seem to sleep for a

few minutes at a time (a phenomenon difficult

to observe in the wild). They can go for weeks

without water by hydrating only with the mois-

ture they suck from leaves. It took five years of

observing giraffes in the deserts of Namibia

before the GCF’s Fennessy, perhaps the world’s

leading expert on giraffes, ever saw one splay its

legs and dip its head awkwardly to drink from

a ground puddle. Witnessing this gawky effort

to obtain the most basic sustenance makes one

wonder if the right question to ask isn’t why the

giraffe has such a long neck, but rather, why is it

so short relative to such long legs?

In truth we still don’t know why the giraffe

has such a long neck. According to Nikos Sou-

lounias, an evolutionary biologist at the New York

Institute of Technology, the giraffe evolved on

the Indian subcontinent and migrated to Africa

from Asia some eight million years ago. Its closest

living relative, the okapi, which lives in the equa-

torial rainforests of the Democratic Republic of

the Congo, noticeably lacks its cousin’s long neck.

Giraffes are naturally topiarists, eating the

acacias into hourglass profiles that fan up at the

top, just above the “browse line” where the ani-

mals’ towering necks and outstretched tongues

can no longer reach, and so it would make sense

that the long neck evolved to open up a feeding

niche unavailable to shorter species. But some

researchers have suggested that the giraffe’s long

neck is actually a function of sexual selection. Its

principal benefit is not for foraging in the upper

reaches of trees but rather for males to more

effectively club each other with their pendulous

heads, outfitted with extra-thick skulls, when

competing for females in heat. Or perhaps the

giraffe’s long neck is simply to give an otherwise

fairly defenseless animal a high vantage point to

watch the horizon for predators.

Undoubtedly linked to the giraffe’s long neck

is its eerie silence. Giraffes almost never make a

sound and don’t communicate with each other

using any kind of signaling audible to human

ears. Their silence is especially bizarre given that

they’re social creatures that live in a fission-fusion

society, in which groups of individuals frequently

IN 2016 SOME SCIENTISTS

CAME TO AN EPIPHANY

ABOUT GIRAFFES.

GENETICS REVEALED THAT

THE ANIMALS HAVE FOUR

DISTINCT SPECIES, NOT

JUST A SINGLE ONE.

108 NATIONAL GEOGRAPHIC