Grazing goats are becoming a common sight in Los Angeles – can they really prevent ever bigger, fiercer wildfires?

New Zealand's remarkable birdlife evolved on a land without apex predators. Introduced cats have decimated their numbers. New Zealanders may have to change the way they keep cats.

From bearing the burdens of the Roman Empire to enabling trade over long distances, the humble donkey has been surprisingly influential.

Dogs, like humans, need to learn basic "life skills". The training helps them deal calmly with other dogs and humans – and lets them live a happier, stress-free life.

From a vegetarian dog to a walking piece of kitchen equipment, the world was once home to an abundance of strange hounds. Where have they gone – and could we bring them back?