Does the mother love bird have to sit on the egg most of the time?

Yes, in many bird species, the mother (or sometimes the father) does need to sit on the eggs most of the time to provide warmth and maintain the appropriate temperature for embryonic development. This behavior, known as incubation, ensures that the eggs remain viable and hatch successfully. The parent may take turns with the other parent or leave the nest briefly to eat and care for themselves, but consistent contact with the eggs is crucial.