I’ve visited Murcheson Falls N.P. in Uganda several times over the last 10 years. It is a great place to observe giraffes.
I’ve also observed them in Namibia, Tanzania, and Kenya. They are truly unique animals.
Everything about the giraffe is stretched to the extreme. According to Joshua Foer (writing in NG magazine):
There’s its famous neck, of course, but also its outrageously long eyelashes, its legs (the longest of any animal), its eyes (the widest of any land mammal), its elongated skull, and especially its purple-black prehensile tongue, which can extend over a foot and a half from its mouth and nimbly strip bare an acacia stem so thorny you wouldn’t want to grab it with your bare hand. Even its heart, which pumps blood over a greater vertical span than any other land mammal, can be more than two feet long, with ventricle walls more than three inches thick.
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 moisture they suck from leaves. It took five years of observing giraffes in the deserts of Namibia before the [Giraffe Conservation Fund’s Julian] 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 Soulounias, 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 equatorial 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 animals’ 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 get together for a period of time before dissolving. Other species with fission-fusion societies, such as elephants and chimpanzees, tend to be loquacious communicators. This has led some researchers to suggest that giraffes may emit low-frequency infrasound to communicate with each other over long distances (similar to the low-frequency rumblings of elephants), but so far the evidence has been mixed.