Predators have roamed the planet for 500 million years. The earliest is thought to be some type of simple marine organism, a flatworm maybe or type of crustacean, perhaps a giant shrimp that feasted on ancient trilobites. Much later came the famous predatory dinosaurs such as T. rex, and later still large toothed mammals such as sabre toothed cats or modern wolves.

But one or two hundred thousand years ago, the world’s most powerful predator arrived.

Us.

We lacked big teeth or sharp claws, huge tentacles or venomous bites. But we had intelligence, and the guile to produce tools and artificial weapons. And as we became ever better hunters we started harvesting animals on a great scale.

We wiped out the passenger pigeon, the dodo, the great herds of North American bison. Last century we decimated great whale populations. Today the world’s fishing fleets routinely take more fish than scientists say is sustainable, leading to crashes in cod numbers for example, while people kill more large mammals in North America than all other causes put together.

But out of our mass consumption of the world’s fauna appears a curious conundrum.

Here's a look at just a few of the world's most endangered species:

Greater Horseshoe Bat

Rhinolophus ferrumequinum

IUCN Status: least concern

Population trend: decreasing

There are eighteen species of bat in Britain and all of them are endangered. The greater horseshoe bat is one of the rarest. One reason for their decline is the destruction of suitable roosting sites, such as old buildings and hollow trees. Changing land use from woodland and small fields to large scale agriculture has also had an effect. They have also suffered from the use of insecticides (poisonous chemicals sprayed on to crops to kill harmful insects) which have deprived the bats of their insect food. Due to conservation efforts its population in the UK has stabilized at about 5000.

Siberian (Amur) Tiger Panthera tigris ssp. altaica IUCN status: Endangered Population trend: stable