I found an egg! A little white egg will the bird come back for it? Is it abandoned?

I moved my plant inside to water it and discovered why I saw a bird sitting in my shamrocks (it's a hanging wall basket with coconut liner) I havent' seen the birds visit in the past two days though, won't they usually sit on the egg all day and night... night here it's 54 degrees. Would it be a mistake to take the plant and hang it back up outside? I didn't touch the egg but I did touch the hanging basket... bird people that know was this egg abandoned? I saw two birds two mornings ago hangin out in the plant they're grey and look like the same size shape as a dove. They make a lot of cewing noises when they fly around. What kind of bird is it? Is it normal to leave the egg alone for so long?

I found an egg! A little white egg will the bird come back for it? Is it abandoned?
is the egg in a nest in the plant? If there is only one egg, the bird may still in the laying process, and most birds will not start incubating them until all or almost all are laid...this can explain why they are not caring for it yet. Put the plant back where it was and they may come back and finish laying. It could also be that they decided this was not a good nesting area and have moved on to another site. Are the birds Mourning Doves perhaps? They commonly build nests in plants.

http://www.drundel.com/dove/morning.jpg
Reply:DEFINITELY put the nest back. They will most likely return to lay more eggs in the next few days. Females only lay one egg per day, and don't incubate until the clutch is complete or nearly complete, so don't worry if you don't see them around!
Reply:Leave the egg alone. There is no way unless you are an expert to tell whether or not the egg was abandoned, or if that is that type of birds usual habit. Also, nature is always best left uninterrupted. Even National Geographic Photographers try to leave the areas they visit undisturbed. Even if it was abandoned, what can you possibly do for the egg? You cannot properly incubate it because you have no idea what the the proper conditions are. Sorry, but stay away :)
Reply:You can hang the plant back outside and wait a couple of days to see if the bird who laid it returns.It is very normal to find an egg in a nest with no parent bird around.The reason is because they do not begin to set on the nest till they have laid their clutch.Typically most birds do not stay around the nest site till they are ready to start incubating the eggs.The first reason is so they do not attract attention to their nest,this helps keeping it safe from predators.The other reason for this is so all the eggs hatch at about the same time.The purpose for the eggs all hatching close to the same time is because the chicks will need to begin being fed.To do this the mother will have to leave the nest to gather food.Being baby chicks eat a lot and often she doesn't have the time to set and incubate eggs and feed the chicks that have already hatched. Even when male and female birds share nest duties as soon as the chicks hatch it is a full time job for both to feed them.Any eggs which did not hatch will be pushed out either by the parents or the chicks in the nest.There are very few things which will cause a bird to abandon it's nest.yet in the event they do.It is still best to leave things as you found them.Because there is no way of knowing if the eggs are still viable.It is perhaps one of natures cruelties.but all part of the process.