how do bird’s eggs retain enough heat to survive when their parents are not actively sitting on them?

Question

I’m sure some of it depends on the species of bird, but I still don’t get it.

In: Biology

Answer 1

Eggs in a next are left alone very little if at all, with most species if birds. They can go a few minutes, even hours, without a parent setting, but not much, not often.

What that means is the mom and dad just stay on the nest, night and day, take turns, etc. until they do hatch. Hunger, cold, and danger be damned.