Birds in captivity will immitate other calls made by humans. Then there is a one or two note call used by a male to get a female to come to a nest. After mating the male will give a series of very short coos having a frequency of around two per second and lasting for a minute or more during which the male and female both remain still. Only the beak on the male moves. There is an alarm coo which may be several short but loud coos when danger approaches.
Diamonds seem to be a very affectionate bird.
When one bird of a pair returns to a nest they often great each other with very low, raspy coos. When the birds become separated they will make a two note call until they become reunited. Two white eggs usually laid one day apart. The eggs are incubated from 13 to 14 days. The male will sit on the eggs during the day and the female will sit on the eggs at night.