Do doves only have one mate?

I don't know for sure, but I did have a pair of doves as a child. We put them on the porch one day(in their holding cage) to clean their area and the neighbor's cat killed one of them. After that the other one refused food and eventually died. She was a wonderful bird and it broke my heart. I don't know if a dove needs a mate, but I do know he/she needs a friend.