It is necessary for us to understand something of nature’s process by which the normal bird is supplied with its feathers.  Nature has provided that a bird shall grow one coat of feathers each year.  In the wild state, this takes place in our latitude and in the northern hemisphere in the latter part of July, in August, and the first part of September.

The moult begins at the hottest period of the year and ends at the time when the first cool weather of autumn maybe expected.  These facts should be kept in mind for they furnish us with the only reliable means of controlling the moult that is now known.  When a bird is placed in a room having an abnormally high temperature or when is subjected to a sudden variation in temperature he will almost always go into the moult.  The temperature change appears to upset the functioning of the thyroid gland, which governs to some extent all growth activities. 

Although, there are other glands that play an equally important part.  It is a balance between the activities of a number of glands that govern the state of the body.  In this question of feathers, the sex glands are primary importance.  When the sex glands are active, the bird does not moult.  The cock roller, for example, will be in full courting swing and the hen will be in a breeding condition.  They will both be very active and have a high rate of metabolism.  Metabolism is the process which food is converted into energy. 

When the sex glands are active, there is also increased activity in the thyroid gland.  When the thyroid gland is inactive, the rollers can not be brought into breeding condition and will be sluggish, inactive and will put on fat with great ease.  Cocks and hens alike will sit around with feathers held loosely.  They are not sick, but the cocks will not coo for mating and the hens will not mate.  They go into moult easily when placed in a room having too high a temperature.  This last state corresponds to the winter condition of birds in the wild state.  It is a natural provision whereby the body decreases its activities during the months of bad weather and stores up fuel as a protection against interrupted food supply.  The loosely carried feathers enable the bird to keep itself warm with the expenditure of the least amount of energy, and every grain of fat it carries maybe needed to sustain life should it be caught in a blizzard. 

It is commonly observed fact that where two physiological functions depend upon each other as cause and effect.  The existence of either will lend to bring about the existence of the other.  The existence of the moult will stop breeding and the existence of too much fat will also stop breeding, while stimulation of the sex glands will stop moulting and lead the reduction of fat. While birds in general live in the natural state, the bodily functions fall into a natural order but when a man takes a hand, this order is very often upset and becomes impossible to say which comes first.  

Possible death to exhaustion:  many fancier breeders, especially the novices, will over-feed their rollers at the end of a breeding season.  Either they may want that extra nest of rollers or they may merely be ignorant and think that they are being kind to their birds.  The over-fed rollers stay in breeding condition.  Often it happens that the rollers have started to moult while raising a nest of birds and have been stimulated in order to save the youngsters.  Often the pairs of breeders have been bred for five, six, or even eight nests with no regard to their condition.  Therefore, they will not moult and the feathers that they have wear out, and in some instances are left naked.  In many cases, the breeder pairs or the hens in particular, have been so exhausted that should she be forced into a moult she will die, because she is unable to metabolize the materials necessary for the production of feathers.

Baldness due to lack of feed necessary for feather production:  many fanciers do not realize that a roller needs special food during the moulting season and do not give it the food necessary to make the feathers.  They feed it some stale packaged seed and expect it to grow a coat of feathers on that.  Well, it usually tries and makes the best of it, but it ruins its digestion in the process, and is very apt to get sick and possible death just about the time it gets nicely feathered.  But in most cases the roller saves its digestion and gets bald instead. 

Roll-downs due to the moult:  most young rollers are moved to the kit box at the time they are feathering their heads at the end of baby moult.  Some are apt to be well advanced in their growth and the breeder is over anxious to get them into the kit box and onto a kit diet before they develop.  The young rollers are transferred a little too soon and the diet changed a little too drastically.  The result is that the young roller comes into full rolling at once and at the same time stops moulting the head feathers and the young roller is transformed into a roll-down and possibly a chronic roll-down.  Also, the same may happen with any moulting roller.  Locking up a young roll-down for a week or two and feeding rich grains may not reverse this transformation or the psychological damage.  A cold room, or too stimulating diet that brings the roller into breeding condition before the moult is ended, may stop the roller from moulting all of its feathers and then if a new moult is not forced, the roller will go bald.  

 Possible treatments:

 It is only necessary to remoult rollers that have become bald because of interrupted moult.  This can be done by placing the rollers in a very warm place as a rule, or by moving them from place to place daily for several weeks.  I think that it is usually best to treat the roller so as to keep it in a perfect health and wait for the next moult to correct its appearance. 

The case of the rollers exhausted from over breeding, the treatment is not so simple.  It is often impossible to force the rollers into moult by the usual process, and best is to turn them into kit birds for six months or more and then, if they do not remoult themselves, to try to cause them to remoult.  It is useless to try to breed such birds while in that condition; they cannot produce chicks that will live.  Though once they have gotten to moult fully, they are as good as they ever were. 

The only thing to do in cases where the roller has not had the necessary food is first to build up the health of the roller and then cause it to remoult.