Not only is this extraordinary spider an entirely new species previously unknown to science, but it is half male and half ...

All hummingbirds fight. Most species fight for food, using their tiny bodies and sharp bills to force competitors away from ...

In our complete guide to bird lifecycles, we lead you from nesting and hatching all the way back to the mating season.

Female and male brains are very similar, but on the level of molecular mechanisms, clear sex differences emerge, revealing ...