Logically speaking, you would think that animals who appeared to be the same – even if they were found in different parts of the world – would belong to the same species, and that they would share the ...

The energy invested in animal reproduction is as much as 10 times greater than previously estimated when the metabolic load of bearing and caring for offspring is accounted for, according to a new ...

Beyond birds, a surprising array of animals reproduce by laying eggs. From the unique monotremes like the platypus and echidna to reptiles, amphibians, and intelligent octopuses, this ancient strategy ...