Giraffes: Earth's threatened giants

Giraffe numbers have plummeted in recent years, with conservationists warning of the "silent extinction" of the world’s tallest land animal. Just 97,500 now exist in sub-Saharan Africa, falling almost 40 percent since 1985, says the International Union for the Conservation of Nature. Check out this week's eco@africa show to see how giraffes are coming back from the brink of extinction in Niger.

These majestic creatures have suffered from disease, habitat loss and illegal hunting for bushmeat, as well as collisions with vehicles and power lines - there are now fewer giraffes than elephants in Africa. Campaigners say giraffes now face additional pressure from "trophy" hunters traveling to Africa to shoot their big-game quarry - these hunters mostly come from the US.

In 2016, researchers found that there are not just one but four distinct species of giraffe. The research, published in the journal Current Biology, is now being reviewed, but if formally recognised as four separate species, three of those four would suddenly be deemed more seriously threatened on the IUCN's list of endangered animals, hopefully prompting greater conservation efforts.

Giraffes' necks can be as long as six feet – despite only containing seven vertebrae, the same number as a human's, although a giraffe's are elongated. For blood to reach the brain, the heart must pump it to a height of two meters. Scientists are still trying to solve the mystery of how the giraffe got its neck.

Pregnancies are long, lasting up to 15 months, and end with the giraffe giving birth standing up – that means their offspring have rather a bumpy welcome into the world, having to endure falling more than five feet to the ground at birth. But baby giraffes are fast learners: they can stand within just 30 minutes of the birth and can run with their mothers only 10 hours after being born.

Giraffes eat most of the time, chewing through hundreds of pounds of leaves each week and must travel miles to find enough food. But its height can make drinking difficult and dangerous. To do so, they must spread their legs and bend down, making them vulnerable to predators. Thankfully, giraffes only need to drink once every several days, as they get most of their water from the plants they eat.

A giraffe's 21-inch tongue is crucial in helping them pluck leaves from branches–and also helps in the birth process. Giraffes graze on leaves and buds in treetops that few other animals can reach, with acacias a particular favorite.