Molting in Birds

Feathers are a truly phenomenal, complex, and beautiful structure. Like hair or fur on mammals, they have many very important functions. Feathers insulate to maintain body temperature and protect birds from the elements (cold, heat, and water). Feathers play an important role in aerodynamics and flying. They are used for camouflage, display during courtship, demonstrations of territoriality, and they indicate sexual dimorphism (differences between the sexes) in many species. Molted feathers can also be used as nesting material.

 

How do feathers grow?

Each feather occupies a single feather follicle. Unlike hair, feathers do NOT continually grow; once a bird's feathers have grown in, they cannot be repaired if they become worn or damaged. As long as a feather occupies a feather follicle, it will not be replaced. Feathers need to be removed or fall out to stimulate new feather growth.

 

What is molting?

Molting is the shed of old feathers to make way for new feathers. To keep itself in fine feather, a bird needs to molt each year to get rid of old or damaged feathers. Molting is required to renew a bird's plumage and keep it in top condition. Having complete plumage facilitates efficient flight, temperature regulation, protection, and courtship displays.

 

When do birds molt?

In the wild, molting is usually related to the change of seasons or the changing day length. Change of season or daylight hours stimulates molting, migrating, and breeding. Other factors that influence the timing of the molt include temperature and available nutrition, as well as the bird’s general health and reproductive state. Most wild birds molt heavily in the spring and fall; between seasons they may continuously replace old or lost feathers. Over a one-year period, every feather is replaced with a new one. Molting occurs in a gradual, bilateral, symmetrical sequence, so that the bird is not left bald and unable to fly.

"Molting occurs in a gradual, bilateral, symmetrical sequence so that the bird is not left bald and unable to fly."

In captivity, birds’ bodies can become unconsciously confused, as they are exposed to artificial light sources that we turn off and on at our convenience. Pet birds are not exposed  to seasonal light and daylength fluctuations in our homes that would mimic seasons. Our schedules, and therefore the schedules of our pet birds, vary from day to day. Pet birds’ exposure to varied light cycles may lead to irregular, incomplete, or long or short molts. In some cases, molting may occur continuously or may only occur every couple of years.

 

Does my bird need anything special during a molt?

During a molt, proper nutrition is of utmost importance. Ideally, nutrition is optimal all year round, not just doing molting. During the molt, there is an increased demand for protein, calcium, and iron. Building a new feather requires a lot of energy and plenty of good quality nutrients. Building lots of new feathers (as in a heavy molt) can be very stressful and taxing on a bird's body. Some birds become less active, quiet, or stop laying eggs and some birds, such as canaries, may stop singing while molting. Birds may become more prone to health problems during these stressful times, as their immune systems are also under stress.

"Building lots of new feathers (as in a heavy molt) can be very stressful and taxing on a bird's bodily resources."

If your bird is having irregular molts, abnormal feather growth, or you are just not sure if his molting patterns are normal, the bird should be examined by a veterinarian familiar with birds to determine whether treatment is necessary.

This client information sheet is based on material written by: Laurie Hess, DVM; Rick Axelson, DVM

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