Cats of the world
There are around 40 extant species of cat around the globe, ranging from the tiny rusty-spotted cat to the well-known big cats (including tigers, lions, jaguars and leopards).
Cats are one of the most recognisable groups of mammals, and have even made their way into our homes.
The extant Felidae family is split into two subfamilies, Pantherinae (big cats: tiger, lion, jaguar, leopard, snow leopard, clouded leopard and Sunda clouded leopard) and Felinae (all other species). The exact number of species is unclear, as some subspecies are occasionally referred to as distinct species (such as the Iriomote cat), but there are roughly 40 species described by scientists.
The BBC One series Big Cats uncovers the secret lives of some of these remarkable felines, including many which are very elusive - snow leopards and Pallas's cats are respectively known as 'ghosts of the mountain' and 'small ghosts of the grasslands'.
About the photographer
Paul Williams is a TV producer and wildlife photographer, based at the BBC Natural History Unit. View more of his photos on Instagram.
To view the images as a slideshow, click on the arrows in the top right hand corner of the photos below.