Nutition will be key in helping your birds through their molt. It is, in fact, the most important aspect. Get the nutrition right and you'll have very few problems in the aviary!

When a feather is replaced, the old feather is pushed out by a new one much like your fingernails or hair. The new feather is often coated in a white sheath of keratin that will flake away as the bird preens and bathes. A healthy bird receiving proper nutrition will replace these feathers rather quickly (a healthy Gouldian should replace its feathers within approximately 4 weeks, give or take a week).  Should they accidentally break off a flight feather and you pluck it, the feather will begin to grow back almost immediately. Because of this, many hookbill keepers will CLIP flight feathers to prevent flight instead of plucking them - because the feathers will grow back rather quickly. They know a healthy bird will replace that feather quickly, and they'll have to pluck those feathers again. Because you should never clip a finch's wings, you can pluck broken feathers, but it is advisable to wait until they complete their molt unless you are showing the bird and need that broken feather gone.

The molt is hormone, heat, light & nutrition driven. They are all interconnected and will affect not only the speed of your bird’s molt, but also the quality of the feathers produced.

Gouldians, in particular, live in areas that can become very hot during the day and near freezing or below at night. As the seasons change, the birds’ bodies sense the approaching season and prepare for breeding, molting, raising chicks, the dry season, or resting. As hormones surge or dwindle, a new cycle begins. Birds in captivity tend to adjust their cycles to the light, heat and nutrition they are receiving, which means they will also adjust when they molt.

In birds with young who look different than they will as adults, the molt can help you determine the birds age by the color of the feathers before and after the molt. Gouldian young, for instance, are olive green when they come out of the nest, but “color up” during their juvenile (first) molt. Budgerigar young have dark bands (stripes) from the top of their head, down their foreheads, and right down to their cere, but as they age, those bands are replaced by solid colored feathers and the black feathers “move back” as the bird ages toward the top of the head. These bands can often help the keeper determine age.

Each different species you keep will have a different pattern of molt ~


Gouldians tend to being their molt not long after their last chick leaves the nest. Pin feathers become obvious on the head, while the color begins to fade on the breast (yes, even in white breasted birds). They tend to replace all of their head and body feathers, while only molting a handful of wing and shoulder feathers.During a good hard molt, they may act sleepy or "down". In many cases, you may think your bird is actually sick. The molt is very hard on the system and takes a lot of energy reserves to replace those feathers. This leaves the birds feeling less than chipper. Once the main body feathers are in, they tend to take a few weeks off, then the wing and shoulder molt begins. At this point they are usually acting more like normal. Because they don’t TYPICALLY lose all their wing feathers at the same time, they are usually still able to fly, but in captivity, that is not always the case. You may find a molting bird floor-bound for a week or so until it has regained enough of its wing feathers to fly up to a perch again.


Opportunistic species will molt at any given time as long as nutrition is right and they aren’t in danger from predators. They tend to molt fewer feathers at one time than Gouldians do, but also tend to finish up more quickly.


The molt is an important part of a finch’s annual cycle.

Light, heat and nutrition will all affect WHEN your Gouldians (and other finches) molt. Many Gouldian breeders like to show their birds. But a simple move from flight to show cage can throw the bird into a molt. Yes, that sounds silly, but the phrase, “Gouldians molt at the drop of a hat” is really not so far from the truth. And if they aren’t receiving enough light, they may even end up in an almost perpetual molt OR won’t replace their feathers at all, which can leave them looking lackluster and dull. If your bird hasn't gone through a molt in a year, you should take a close look at its environment. Lighting will be your first goal. The molt occurs during seasons with the least amount of light. If your bird is receiving more than 8 hours of daylight, it may not molt on time. Breeding season light tends to be best at about 12-14 hours of daylight. In order to induce the molt, the light must become less. Changing timers slowly to emulate the natural movement of the sun over the course of a day is recommended, but if your bird is getting too much light without the use of timers - perhaps the bird is located in your den where you watch television late at night - covering the cage is the next best option.

The molt also occurs in response to a mixture of hormonal changes brought about by seasonal changes.

It takes a lot of energy to build new feathers. As a result, timing is important, and birds typically time their molts to avoid other periods of high energy demands, such as nesting or migration. Molt timing can be more complicated for larger birds, because growing larger feathers means that their molt process takes longer than it does for smaller birds. This is one reason why some birds undergo partial molts.

Following is an excerpt from the Cornell Lab of Ornithology. It has a more indepth look at what I’ve tried to explain about “annual” and “opportunistic” molts:

As with every other portion of your finch's cycle, nutrition is paramount during the molt. If you can get the nutrition right, you'll see very few issues in the aviary - and very few issues during the molt. A diet high in Biotin (Vitamin B7), protein, calcium, iodine, Vitamins A and D3 are all necessary. Biotin is the power nutrient here. It is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids, all of which aid in feather production, but the other nutrients are also imperative. A good vitamin supplement system made specifically for birds (and often specific species) will give them what they need "when" they need it. Products included in such systems like Dr. Rob Marshall's Health Programmes, come with directions for every cycle the bird will go through.  Other product lines have a different vitamin supplement for every portion of a bird's cycle. Morning Bird, for instance, has Hearty Bird, which is an all-season vitamin supplement, but also has Breeder's Blend for use during the breeding season, Feather Fast for use during the molt, etc. So you see, it is important to know your products, what their uses are, why to use them, and WHEN to use them.


Seed & Other Food Supplements


Dark, oily seeds mixed in with the regular seed diet will add the extra protein and the fatty acids required. Chitted or sprouted seed, as well as egg food also make good supplements at this time. Some powdered vitamins are made to be sprinkled over the food. But should you use liquid vitamins in the drinking water, they should be offered on alternate days to the wet foods - in other words, on days you do NOT offer wet foods.  Unless raised to accept liquid supplements in the drinking water, your birds may not like the vitamin supplement in the water and will go for the moisture in the wet foods before they'll drink. While they'll receive the moisture from the wet food, they may not get enough to remain hydrated. This can lead to dehydration which is devastating to a molting bird. Hydration is key for skin and feather health - especially in molting birds, but in birds at all stages of their cycle.

YOUR BIRD & THE MOLT

KRISTEN REEVES, MEADOWLARK FARMS AVIAN SUPPLY, INC.

One of the most common issues that deter folks from keeping Gouldians and other pet birds is their propensity to molt at least once per year, and  sometimes more often. When they go into their annual (or semi-annual) molt, the feathers can end up EVERYWHERE!  The cage and the area surrounding it will often look like it snowed as the fine downy feathers are released for replacement, and then colorful as the body feathers begin to be replaced. It’s a messy time of the year, but it is also very important. Read more below to find out just why it’s so important and what the molt really is!

What Is The Molt?

The word “molt” can be used as both a noun and a verb. It is the name of a function, but is also an act.

Feathers are made up of keratin, which means when they get damaged or brittle, they cannot be repaired and must be replaced. Because a flighted bird needs its feathers to fly, and unflighted birds need them for warmth and protection, these damaged or brittle feathers must be replaced. When a bird replaces a feather, it replaces the WHOLE feather, not just a portion. The is called molt or “the molt". The act of replacing the feathers is called molt (verb), but so is the portion of the bird’s cycle (noun).

Nutrition During the Molt

“The most common approach used by bird watchers is to distinguish between winter (non-breeding) plumage and summer (breeding) plumage. This approach works fine on a casual basis but is inadequate for detailed analysis of molt.  For that reason, scientists typically use a system known as the Humprey-Parks nomenclature, which can accommodate the variability in molting patterns—especially those of tropical species, seabirds, and other species that do not follow an annual cycle.

Humphrey-Parkes

At the heart of the Humphrey-Parkes system is the concept that all birds have a basic plumage, and many birds also have an alternate plumage. These are often (but not always) analogous to winter and summer plumages, respectively. Humphrey-Parkes can be a little confusing to bird watchers accustomed  to thinking of a bird’s bright summer plumage as its main look. In the Humphrey-Parkes system this is called the alternate plumage because the birds spend only a small part of the year in these brighter feathers. The rest of the year they’re in nonbreeding plumage, often following a full molt. This plumage is called the basic plumage.Species that look the same way on a year-round basis are always in basic plumage.The more colorful spring breeding plumage seen in many species is referred to as the alternate plumage under the Humphrey-Parkes system.

An advantage of the Humphrey-Parkes system is that it gives the ability to describe molting and plumage patterns throughout the life of a bird. This means the system can help scientists and bird watchers determine how old a given bird is..”

The Humphrey-Parkes system was first proposed in the scientific journal The Auk in 1959: Humphrey, P.S., and K.C. Parkes. 1959. An approach to the study of molts and plumages. Auk 76:1–31. 

https://www.allaboutbirds.org/the-basics-feather-molt/