I recently spoke to an Aviculturalist who swore by the design of the nestboxes he supplies to his Gouldians. It is similar in design to a lovebird nestbox, in that it has a partition between the entrance hole and the nesting chamber. His theory is that Gouldians like the interior of their nests to be extremely dark, and private, and this design provides those features. It is also more likely to experience less draughts getting in, and will also tend to retain more heat in the nesting chamber.
The overall size of the nestbox is 25 cms long by 15 cms high by 15 cms wide and the lid hinges for ease of cleaning. There is a partition 15 cms from one end, giving a 15 cms cubed nesting chamber. The remaining 10 cm area has a raised floor, giving a ‘step-down’ effect to the birds entering the main nesting chamber. An exterior entrance hole is drilled in the front of the long side, on the end with the raised floor, and a perch is fixed below the entrance hole. There is another entrance hole drilled in the partition, between the entrance chamber and the nesting chamber. It is best to put this hole toward the rear of the box to eliminate as much light as possible.
Prior to mounting the box on the aviary wall, sprinkle a little mite dust in the bottom (such as Pestene™) and, because Gouldians are often lazy nest builders, half fill the nesting chamber with grasses or other nesting materials, then push your fist into it to make a round cavity.