When Birds Molt
By Ron Hines DVM PhD
2nd Chance Sanctuary
All birds undergo molt once a year. Molt is the normal mechanism that birds use to replace worn feathers. Molt in birds is entirely under hormonal control. During molt birds become very vulnerable. Molt lasts several months in some species and a matter of a few days in others. Lack of molt is a sign that the bird 's normal cycles have been disrupted. Molt and the regeneration of feathers puts enormous stress on the bird's body. Molt occurs when the feather follicle looses its grip on the bird's feathers. All feather follicles are under strict hormonal control and are only active during molt. Birds become secretive and try to hide during molt when their ability to fly is lost or decreased.
Feathers are a bird’s most precious possession – the gift of flight. However, after about a year, these delicate structures wear out. Hormonal processes, originating in the pineal and pituitary portions of the brain - tied closely to light and reproductive cycles govern the time and sequence at which the old feather is lost and a new one replaces it. Most birds molt once a year, but some have a second molt to more colorful “breeding plumage” or, for stealth, as season and foliage color change. It is said that Eagles complete a molt every two years. Although I care for permanently injured eagles and have noted that shedded feathers are few, I have not confirmed this. Some people believe that a new feather pushes out the old feather. This is not actually the case. For example, if a feather is plucked or accidentally lost, the feather follicle quickly replaces it - much like we replace hair. The process of molt in birds ranges from a few days to a few months. Incomplete molts are a sign of physical or psychological problems. The same hormones involved in molt are also involved in reproduction, broodiness and cause concurrent changes in a bird’s mood, feeding habits and activity. Parrots, macaws and penguins I have owned, all appear depressed and moody during molt. All new feathers in birds begin as living blood-filled structures. When they are mature, feathers are no longer living. During the time of feather molt, any trauma to the new feather will cause bleeding that is hard to control unless the new feather is manually extracted. Some owners are brave enough to do this with a grasping tool and then maintain pinch pressure on the follicle for a few minutes. Others would rush them to the veterinarian. Should the new, damaged feather remain, it will unfurl distorted or even become ingrown and a source of pain and an invitation to feather plucking. A normal feather emerges, as a collapsed spine-like structure, much like a closed umbrella. This spine is surrounded by a thin, waxy (keratin) sheath (the pin feather). During this stage it is a very fragile structure – easily susceptible to injury if a bird is caged, nervous, or if mature feathers do not surround it. That is why I never clip the first four primary feathers on any pet bird. The molting process is a major strain on a bird’s body, drawing on the bird’s protein and caloric reserves. Latent (silent) health problems often become apparent during , or shortly after molting. As pets, the natural rhythms of molt are altered by life under artificial lighting as well as due to the lack of pair bonding and natural social and seasonal clues.
Parrots & Macaws
Macaws and parrots molt in earnest after they raise their young. Even though parrots constantly preen their feathers, the feathers don't last much over a year without getting frazzled from wear and tear and grooming. Much like some people bite their fingernails to overcome stress, over-grooming is a common way that parrots cope with boredom, stressed or poor nutrition. If a macaw, for example, is off feed for even a half day during the time a feather is forming in its follicle - you will see a "stress bar" - a little line across the feather as if it had been scored or cut with a scissors at that point. The presence or absence of stress bars are a good indication of the bird's general health but although its quite difficult to hand-raise parrots without a few stress bars occurring especially on macaw tail feathers. The next set of feathers usually come in unblemished. It’s a bad sign in mature birds – a reason to visit an avian veterinarian. To an untrained eye, incomplete molt or feather picking can be confused with a much more serious problem – psittacine beak and feather disease (PBFD). The most unusual molts I have witnessed are the climax molt of the penguins I have cared for. Mine used to go off into a corner of the exhibit, look quite depressed and forlorn, go off their feed, swell up enormously with fluid (subcutaneous oedema) and then, within a period of two days, completely replace their feathers! I had to cut off all their wing bands before their molts because they got tight enough to impede circulation due to the natural swelling. The reason penguins have the most dramatic of all bird molts, is that they would freeze if they stayed naked any longer than a day or two in the sub-an arctic cold. Parrots aren't nearly that dramatic. They loose a feather here and a feather there. One of the great mysteries and miracles of Nature, I know of, is that they loose the same feather on the opposite wing just about he time the same one falls out of the other wing. The same thing happens in most bird species Nature is just so amazing. Macaws and parrots would probably have a more even molt if they only saw natural lighting. In their wild tropical setting, the whole hormonal cycle – leading to molt -starts when the days begin to lengthen. But most of us have our birds indoors with artificial light, which complicates matters. During the stress of molt , I recommend that during molt, parrots and macaws be fed feeding a diet a moderately higher protein (19.5% vs 15.5%), vitamin D3 (1500 vs 1350) and calcium (1.2% vs 0.85%), on a dry weight basis. I do not recommend vitamin supplementation because both vitamin A and vitamin D are toxic if the birds get too much of them.