Winter poses several challenges for birds. Scarce food supplies and limited water are just a few obvious challenges for nearly all of them. Extremely cold temperatures, strong winds, driving snow ...

Sixty-six million years ago, at the end of the Cretaceous Period, an asteroid impact near the Yucat n Peninsula of Mexico triggered the extinction of all known non-bird dinosaurs. But for the early ...

Dinosaurs had sex. Fossil nests and eggs, as well as the ways today’s birds and crocodiles reproduce, leave no doubt on that ...