For my colony, the nest boxes are generally placed in the aviary between Christmas Day and New Year’s Day, depending on whether the Gouldians have reached breeding condition.
By this time they have all completed the moult. The cocks should be singing and the hen's beak will be turning black, indicating they are ready to breed.
Gouldians in the wild nest in various places including hollows in trees. So they like privacy and darkness that is why they have such bright nodules.
I prefer and have success with wooden nest boxes that are closed with a round entrance hole measuring two inches in diameter. The boxes I use vary from 5 inches square to 5 inches by 10-14 inches long. The lids are hinged to allow viewing access.
Since I had problems during 2001 with some wet mouldy nest boxes I have I place a preformed nest of swamp grass on the bottom of the nest box. I use my fist or a tennis ball to form a small hollow. The cock will complete the rest building a canopy from swamp grass left about the outside section of the aviary.
Generally they are excellent nest builders. You will be surprised how the male will finish the rest with a thick canopy and long tunnel into the sitting area.
Even though the nest boxes are in a small area, there are very few arguments among the Gouldians, as long as the entrance holes face away from each other. Another excellent idea is to place guards over the entrance holes to inhibit peering by the other Gouldians.
The nest boxes are all in the indoor section and will remain until July/August depending on what is happening in the aviary.
Gouldians are very curious by nature and will quickly investigate anything new in their surroundings. Before I can get out of the aviary the Gouldians are inquisitively looking into the nest boxes.
All in all, it is always a time of great anticipation!