Why do bird eggs need warmth from the parent to develop, while fish, amphibians etc don’t?

Question

My head can’t get around the idea of why they wouldn’t just grow but slower because of a lower rate of reaction!!

In: 3

Answer 1

Amphibians and most fish are cold-blooded, meaning their temperature depends on the environment.

Birds are warm-blooded meaning their temperature is generated internally, separate from the environmental temperature. If the environment gets too cold, they will die and so must be kept warm