I have a pair of doves nesting on my carport.One of the eggs has hatched but the other one has not.I have not seen a parent dove since last night.I didn't stay up to watch for it but when I got up this morning a parent was not their.I heard them cooing but have not seen them.Will they come back and if not how long should I wait to rescue it.It would be upsetting to me if the baby died.I have been waiting anxiously for their arrival.Ive been looking out for them for about two hours and am starting to grow concern.