The following is an excerpt from Dr Rob Marshall's "Gouldian and Finch Health" book, available online in the Clients Only section.
The glorious colour of the Gouldian's plumage is matched by its equally appealing nature. Shy in nature but gregarious in an aviary with its own kind it has a reputation as one of the more difficult finches to breed. Nowadays with modern knowledge it is a much easier finch to breed. The Gouldian Finch becomes a prolific breeder and a joy to keep when its behaviour in the wild and idiosyncrasies in the aviary are understood allowing its special needs to be met.
The breeding of "coloured" mutations presents a completely new challenge for Gouldian breeders because the problems of "normal" Gouldians are magnified in these far more sensitive and fragile coloured birds. Rarely are the coloured mutations in parrots and finches as beautiful as the colours of nature, and the normal coloured Gouldian is a jewel in the crown of the bird kingdom, but the colour combinations of mutation Gouldians are as stunning as the audacious hues of nature's Gouldian.
Mutations are mistakes of nature and in the natural environment are unlikely to survive. The unenviable challenge for Gouldian enthusiasts is to produce coloured birds in large numbers. This is no easy task because unknown genetic flaws that weaken offspring lurk in the aberrant colour of mutations. Inbreeding is essential for creating a coloured strain but it often produces weak "coloured" offspring further complicating the development of a viable healthy strain. The challenge of breeding coloured mutations is met by paying special attention to feeding, housing and the selection of breeding birds that are strong and vital.
Gouldians are shy birds in their natural habitat and are the last finches to come to water in the morning and evening. In line with their retiring personality, breeding results are better when they are housed with their own kind and are not disturbed. Cocks and hens, however, are protective of their nests and need space for undisturbed breeding. For breeding colour mutations up to five established breeding pairs can bred successfully together in a 3m x 2m aviary. At the beginning of the breeding season when more than two virgin breeding pairs are housed together in a similar sized aviary surveillance of virgin breeders is necessary to identify problem pairs that may compete for breeding sites and cause subsequent breeding failures.
Signs of Breeding Condition
Cocks in "breeding condition" sing and courtship prance to the hens incessantly. The enriched colour of their plumage and beak are signs that the cock is hormonally primed and ready to breed. The beak changes from a dull grey hue to the bright, opal, satin white colour of "breeding condition".
It is more difficult to detect a hen in "breeding condition". Her beak turns almost black in colour and as she is ovulating her rump pushes upward and she drops her tail more vertically. She may also sing to the cock bird and carry nesting material in her beak.
An understanding of the notion of "breeding condition" and its important association with breeding success, breeding failure and the enjoyment of the keeping Gouldians cannot be over emphasised.
Susceptibility to Cold and Wet Conditions
Temperatures are warm in the natural tropical range of Gouldians where unlike other Australian finches they thrive during the extreme summer heat. Other Australian finches wilt as the temperatures rise above 35 degrees Celsius but Gouldians are best at these high temperatures and enjoy bathing in the direct sunshine much more than other finches. They are most active and look their best when basking in direct sunshine and when it is hot. Keep this in mind when breeding Gouldians in an aviary or enclosed room. Flighted aviaries that capture the morning sun help with health problems and sustain breeding activity into the cooler months of the year. Provisions should also be made for additional perches to be placed in the open flight area during hot weather for water baths and sunbaking.
Gouldians look dejected and fluff up during wet overcast weather. They breed best in aviaries away from the humidity of the coast preferring countryside weather conditions of clear skies and hot temperatures that resemble the climate of their natural breeding habitat. The migratory behaviour of the wild Gouldian supports this view. They move northward from their breeding habitat towards the coast during dry winter months when their food supplies have become depleted and return inland in summer after the arrival of the monsoon wet season brings prolonged cloud cover and frequent rains. This northern extremity of their range rarely supports breeding activity. Breeding activity is awakened by extended rains that provide grass-seeds and insects in numbers to support the rearing young. The low humidity (dry air), high temperatures and clear skies of the savanna woodlands away from the coastal humidity and rainfall provide these conditions. Breeding problems should also be expected when similar cloudy, wet conditions prevail.