Red Panda
The red panda was named a panda about 50 years before the giant panda, and it is not closely related to it; it is the only living member of its own family.
Asia
Red Squirrel
In Britain, red squirrels have been pushed out of most areas by introduced grey squirrels, but pine martens are helping them recover by preying on the greys.
Red-crowned Crane
In Hokkaido, red-crowned cranes were reduced to about 20 birds in the 1920s; winter feeding by local people helped them recover to well over 1,000.
Reindeer (Caribou)
Reindeer eyes change colour with the seasons, from golden in the Arctic summer to deep blue in winter, which helps them see in the long polar night.
Reticulated Python
The reticulated python is the longest snake in the world, and very large individuals can swallow prey as big as a deer or a pig.
Rhesus Macaque
The ‘Rh’ in Rh-positive and Rh-negative blood types comes from the rhesus macaque, in which the blood factor was first studied.
Rock Hyrax
Although it looks like a large guinea pig, the rock hyrax’s closest living relatives are elephants and manatees.
Roe Deer
Roe deer are the only hoofed mammals known to delay the development of their embryo: they mate in summer, but the embryo only starts growing in winter.
Saiga Antelope
The saiga’s large, bulbous nose filters dust from the air in summer and warms freezing air before it reaches the lungs in winter.
Saltwater Crocodile
The saltwater crocodile has the strongest bite ever measured for a living animal, over 16,000 newtons.
Sand Cat
The sand cat can survive without drinking water, getting all the moisture it needs from its prey.
Sarus Crane
The sarus crane is the tallest flying bird in the world, standing almost as tall as an adult human.
Sea Otter
Sea otters have the densest fur of any animal, up to about a million hairs per square inch, which keeps them warm without blubber.
Sloth Bear
Sloth bears suck up termites like a vacuum cleaner, blowing away soil and sucking in insects so loudly that they can be heard over 100 metres away.
Slow Loris
Slow lorises are the only venomous primates: they lick a gland on their upper arm and mix its secretion with saliva, producing a painful and sometimes dangerous bite.
Snow Leopard
A snow leopard can leap up to about 15 m in a single bound, using its long tail for balance on steep cliffs.
Snowy Owl
A single snowy owl can eat more than 1,600 lemmings in a year, and the number of eggs it lays depends on how many lemmings there are.
Sockeye Salmon
When sockeye salmon return to spawn, they turn brilliant red with green heads, and their bodies later fertilise the forests along the rivers.
Striped Hyena
When threatened, the striped hyena raises a long mane along its back, making itself look much bigger.
Sumatran Orangutan
Sumatran orangutan mothers give birth only about once every eight or nine years, the longest gap between births of any mammal.
Sumatran Rhinoceros
The Sumatran rhino is the hairiest rhino and the closest living relative of the extinct woolly rhinoceros.
Sun Bear
The sun bear is the smallest bear in the world, and it has the longest tongue of any bear, about 20–25 cm, for reaching into bees’ nests and termite tunnels.
Sunda Pangolin
Pangolins are the only mammals covered in scales, which are made of keratin, the same material as human fingernails.
Takin
The takin is Bhutan’s national animal, and legend says a saint created it by putting a goat’s head on a cow’s skeleton.