The sex of a cutthroat finch (Amadina fasciata), also known as a ribbon finch, is easy to determine, because males have a red stripe on their throats while the females do not. Cutthroat finches will breed year-round in warmer climates, but in captivity you should breed them in summer. Both the male and female in the breeding pair will incubate the eggs and rear the fledglings. Cutthroat finches can lay three to nine eggs, which hatch in 12 to 14 days. Ensure that both the male and female cutthroat finches are at least one year old before allowing them to breed.
Provide a covered nest box filled with grass, stems, shredded paper or coconut fibres. You can place the pair in a separate cage or allow them to breed while among the rest of the flock.
Observe the male and female finches for signs of mating. The male cutthroat finch will turn his head side-to-side with the head feathers standing erect and sing to the female while dipping his body up and down. The female will shake her tail feathers to show her interest in the male.
Keep the hens healthy during breeding and egg-laying time. Prevent egg binding by providing the female cutthroat finches with a cuttlebone or other daily calcium source and a balanced diet.
Offer live food, such as mealworms, fruit flies, crickets, wax moth larvae and ants' "eggs," to the cutthroat finch couple when they're rearing the chicks.
Make a quick visual inspection of the nest each day when you're feeding the cutthroat finches. Avoid handling the nest, eggs and fledglings or otherwise interfering with the nest, especially if the finch pair has abandoned their eggs or chicks in the past.
Help to prevent finch pairs from abandoning their broods (which is common in captivity) by providing a variety of foods, as well as nesting choices and materials, such as dry grass, wool and hay. You can use a small compact mirror and a pen flashlight to inspect the nesting box without touching it. Intruding into the nesting box or checking it too often can make the breeding finches nervous and cause them to abandon the nest.
Don't allow cutthroat finch couples to breed more than two or three times per year. Producing more than two or three clutches of eggs per year can harm the finches' health.