The number that explains everything A female dog, left unsterilised, can produce two litters a year. Each litter averages six ...

A parasitic worm discovered in rats nearly a century ago has quietly spread to every warm corner of the globe, and a single ...

Monogamy, in the animal kingdom, is genuinely rare. It is not the default setting of nature. Most species spread their ...

A Greenland shark stranded in Ireland was more than 150 years old but may have only just reached reproductive age. Its eyes, ...

The real story behind reproduction and a collection of essays focusing on mothers and daughters ...

A small Brazilian cove became a vital nursery for blacktip sharks — and now it is inspiring local conservation efforts.

Birds have a lot to do in their short lives: defend territories, build nests, raise chicks and feed themselves. But the toll ...

As humans moved toward more agricultural pursuits, the social tide began to shift away from the gender egalitarianism and ...

Scientists in Vermont have just discovered something that shouldn't really be possible: a skin cancer that's spreading from ...

With only a few hundred red wolves left, Smithsonian scientist Jennifer Nagashima is pioneering new ways to preserve their genetic diversity.

A new study suggests tourism and human activity off Hawaii Island may be contributing to unexpectedly low calf numbers in spinner dolphins. The study, led by the University of Hawaii’s Marine Mammal ...