The Problem of Poor Fertility in Budgerigars

The problem of poor fertility in budgerigars appears to be a new phenomenon affecting almost every birdroom. This article attempts to analyse the possible causes and offers some solutions.

The development of every living organism is the result of the interdependant effects of Nature and Nurture, during the whole of the individual’s lifetime. If the same individual could be cloned, (exact genetic copies of the same individual organism), and each different clone could be reared in slightly different environments, and fed on various different diets, then it would be possible to determine the precise conditions and diets which are beneficial, or harmful, to growth and development for that single organism. In this example, the Nature of the individual would remain the same, but the Nurture for each clone would be different. Without conducting an experiment of this type, we can only guess at the effects of Nurture upon the breeding and rearing of budgerigars.

When we refer to Nurture in respect of budgerigar breeding, it is more usually referred to as “husbandry”, this term implies the method of housing, feeding etc., which are all in the breeder’s direct control; some breeders are better “stockmen” than others. However, some of the Nurture is outside of the fancier’s control ie., environmental factors etc. If we now assess the various possible different factors under the heading of Nurture, we can see that there are many different external influences upon the individual.

  • Food
  • Water
  • Air
  • Light
  • Temperature
  • Disease organisms
  • Other factors


Most breeders feed their budgerigars on a main diet of various types of canary and millet seeds, and therefore, most budgerigars will be eating the same food from similar sources, but in different proportions to each other. If contamination to the seeds grown over the last few years had occurred from the recent introduction of new pesticides to the crops, then this could be a possible source of problems. If this were the case, the effects on the wildlife in the areas of production would have been reported, and ornithologists and other environmentalists would have informed aviculturalists.


Most budgerigars are given “tap water”, and this can hardly be considered to be pure. Nowadays most water is best considered to be a dilute solution of a myriad of contaminants, which even the water treatment plants cannot remove. Upon occasions, major pollutants reach high concentration in tap water, and so it is best to assume that traces of many harmful chemicals are permanently present. Very few watercourses in Britain support much in the way of thriving fish stocks, and if fish cannot live in water then it cannot do our budgerigars or their owners much good! In the human male, it has been found that the sperm count is now considerably less than was the case only a decade ago, and this phenomenon is already affecting human fertility levels. Water is considered to be a major factor. It would be reasonable to assume that water will have the same effect on budgerigars. The boiling of all drinking water would vaporise many of the organic pollutants and would also destroy many micro-organisms that may contaminate water, thus making the water less polluted.


Like water, much of the air in Britain is polluted, and cannot be considered pure. With so many known pollutants now in the atmosphere, it is unlikely that any of them are beneficial, and most are probably harmful. If, at the present time, air pollution was a cause of infertility in budgerigars, then presumably many other species would have become extinct as a direct result of air pollution. This has not happened.


Outside of your birdroom there are still 24 hours every day, and the daylight hours still vary with the time of year, as they have always done. In the early days of the fancy, breeders did not artificially light their aviaries and budgerigars were prolific breeders, because they bred naturally when daylight length was optimum for reproduction, as do our native wild birds. Most breeders now use artificial lighting to attempt to stimulate their birds to breed in mid-winter, when the daylight length is at its shortest, and when the power of the sun is at its weakest. The purpose of using artificial lighting is to “trick” the bird’s pineal gland into responding as though it is spring with a continuous daylight length of 14 to 17 hours each day.

I have seen some ridiculous systems of lighting management advocated, where the lighting is switched off at midday for the birds to rest for 2 hours. For those who have not noticed, the sun does not switch off at midday. If birds naturally rest at midday, then they do so when the light is strongest. If you are going to use artificial lighting, it should be continuous for 14 to 17 hours or be controlled so that the lighting level in your birdroom is maintained for the equivalent period by the use of electronic controlling devices.


During a normal British springtime the temperature is probably maintained between the extremes of O degrees and 15 degrees Celsius during the same day, with little variation from day to day. Incubating hens can cope with this temperature range and can sit their clutches, providing optimum temperature in the eggs for complete development. Nowadays, the variation of weather on a daily basis, seems to vary over a much larger temperature range than 15 degrees Celsius, and often the weather varies considerably on a day-to-day basis; warm summer-like days and cold winter-like days often occur in succession. During the 17 day incubation period of the budgerigar egg, the external temperature range during that period may have varied between 26 degrees and minus 5 degrees Celsius, a range of 31 degrees; this temperature range is probably greater than a hen is able to cope with. I consider this to be the cause of much of the “dead in shell” which seems to affect most of the eggs which are being incubated at the same time.

If a thermometer that records maximum and minimum temperatures is kept in the birdroom, and the temperatures are recorded on a daily basis, and these temperatures are compared to the incidence of “dead in shell”, then it should be possible to establish if a large temperature range has occurred over the incubating period. If large temperature fluctuations are considered to be a factor, then thermostatically-controlled heaters are required in the colder months to limit the temperature range. If budgerigars are bred in the spring and summer months, similar large temperature fluctuations can occur but short of installing air conditioning these temperature fluctuations are harder to control.

Humidity is also somewhat related to temperature, and long warm periods tend to reduce humidity, as does the use of artificial heating. It is therefore, necessary to ensure that the moisture levels of the air within your birdroom is maintained, by leaving trays of water near heaters throughout the year. The wild budgerigar is an opportunist breeder, and warm moist conditions that occur when food is plentiful, stimulate the birds to breed, no doubt they should respond in a similar way if such conditions prevail in your birdroom.

Disease Organisms

Most large organisms act as hosts for many smaller organisms, such as bacteria, viruses, intestinal worms, insects etc. Some organisms are harmful to the host if the numbers of organisms carried are too great; this results in a parasitic infection, or otherwise known as an infectious disease. During the course of evolution, the higher organisms have developed an immune system which enables the host to protect itself against parasites of many different types. It is perfectly natural for the environment to carry small numbers of many different, potentially harmful, diseases, causing organisms or pathogens. If a budgerigar with a normal immune system meets small numbers of pathogens, then that bird is said to be “immune” to the pathogens that it is now able to protect itself against. Some bacteria are essential to the bird’s existence and live in the gut, usually of the strain known as E.Coli, such bacteria are known as commensal organisms. (Probiotics are basically the supply of commensals to the budgerigar).

Disease will only occur when the immune system is either deficient, overworked, damaged, or meets a virulent attack by parasites. While it is only natural that you should wish to treat sick birds, with regard to the rest of your healthy birds, it is the worst thing that you can do, because the sick bird plays host to large numbers of parasitic organisms, that are then able to afflict other birds in the confined environment of your birdroom. Treated sick birds are probably too damaged to be of further use in your breeding programme, and therefore, they are best disposed of at the earliest sign of disease; the remaining healthy birds can only benefit from the removal of the sick. In the wild, sick birds would get no treatment and quickly perish; it is Mother Nature’s way. Birds which are chronically or sub-clinically infected, will not be in perfect breeding condition and therefore will fail to breed successfully.

Other Factors

There are several other factors which probably have great influence on fertility which Come under the heading of “nurture” or livestock husbandry; the use of vitamins and dietary supplements, and the use of disinfectants. To my mind it is hard to differentiate between these two groups of chemicals and pollutants.

It is only natural that a good stockman should want to provide the very best environment for his prized budgerigars, so that they will fulfil their potential, and to that end, many breeders wish to stuff every vitamin, mineral or additive through their budgerigars’ beaks without asking the question, “Why?” Budgerigars belong to one of the oldest families of birds and have been in existence for millions of years with very little change, they have well proven their harmonious relationship with their natural environment. How have they managed to survive as a species for so long if they need additives that, until recently, were not available to them? If a budgerigar receives a diet of several different varieties of seed from several different sources, then there will be vitamins galore within this diet. Vitamins in excess are known poisons and an result in death.

Likewise, how can the wild budgerigar reproduce in such great numbers, visiting the same filthy nests each year, without the trees being washed down with powerful virucidal and bactericidal chemicals before they go to nest ? The answer is of course, immunity. The relatively recent use of powerful disinfectants into the birdroom has introduced new chemicals into the budgerigar’s environment. If such chemicals destroy bacteria and viruses then it is difficult to see how they can be of benefit to the budgerigar when ingested on a gnawed perch.

There is a need for cleanliness, but not for sterility in the birdroom. Bird droppings are very rich in ammonia and this prevents the development of many harmful bacteria in the nest. It has worked for millions of years and will continue to do so.

It is essential that budgerigars meet limited numbers of potentially pathogenic bacteria, so that the birds develop immunity to them. Also, the regular function of the immune system in an individual keeps the system “alert” to the arrival of different strains of bacteria and ensures the birds’ future self-protection. Attempting to achieve a sterile environment by eliminating every single bug in the birdroom is very counter-productive to the health of your birds. I am not in any way advocating filthy conditions, but a common sense approach to hygiene. I would suggest that the best cleaning agent to use in the birdroom is Sodium hypochlorite (“Milton” or a proprietary “nappy sterilizing” solution.).

Noise and Sight

By nature the budgerigar is a gregarious creature and lives amongst many others of its species. In the wild, the members of the vast flocks of budgerigar breed simultaneously with each other. Budgerigar nesting sites are very busy places, with plenty of “chatter”. If budgerigars are not to be bred on the “colony system” then it seems logical that if pairs are to be kept in cages, then they should not be isolated from the sight and sound of other birds. Very few birdrooms have clear perspex or wire dividers between the breeding cages, and many birdrooms do not have flights full of birds in front of breeding cages.

The budgerigar is a “talkative” creature, and probably vocalises as much as any other creature on earth. Whilst I am unaware that any one has yet studied the vocabulary of budgerigar language, the chatter must mean something to other budgerigars, otherwise they would not have developed such complex vocalization. Budgerigars in great numbers, tend to vocalize more than they do in small communities, and as such, they must be more at ease with their surroundings and hence feel secure enough to go to nest and breed. A radio playing music seems to encourage budgerigars to vocalize and presumably this background noise prevents the birds being permanently alert to outside noises of danger, and hence feel more secure for breeding.


If you believe that you are providing the correct “nurture” for your birds, and have had several consecutive successful breeding seasons in the past, then the problem of poor fertility must lie within the “nature” of your birds themselves.

If you are a budgerigar breeder of long-standing, then it is very likely that most of the birds in your stud today, are the distant relatives of very few ancestors, many generations ago. Unless you have paired your birds, each year, to bought-in, unrelated stock, after a few generations, virtually all your birds will share over 90% of the same genes, whether you believe you are practising outcrossing, line-breeding or in-breeding. In a closed population such as a budgerigar stud, eventually, all your birds will be distantly related to each other.

Natural Selection

In the wild, the process of selection that operates is “the survival of the fittest.” That is, those budgerigars that can survive the rigours of their environment live to pass their genetic information to their offspring. Those that fail to cope with the environment, for whatever reason, do not have the opportunity to leave offspring. It’s a cruel world; some excellent specimens fail the test, but poor specimens never pass the test. One might say that the genetic material passed on from generation to generation in the wild, contains The Secrets of Survival. Those that failed to become parents, must not have had some essential genetic information. The system of genetic selection by the survival of the fittest, is usually termed Natural Selection. Mother Nature could not give two hoots about deep undivided masks bearing enormous spots, directional feathering, small tucked-in beaks, etc. If such features could enable the budgerigar an improved chance of survival, no matter how slight, then such features would be preserved and passed on to the next generation. The fact that such features are not seen in wild budgerigars, would indicate that the possession of such features confers no advantage to survival and more probably are disadvantageous to survival.

In your birdroom, natural selection does not operate. Here we have artificial selection in practice. You now make the rules rather than Mother Nature. Do you operate the principles of survival of the fittest, in conjunction with selection of the desirable features of the exhibition Budgerigar? If you do not ruthlessly cull poor breeders, birds of low vitality, weaklings and other misfits, no matter how close to the Ideal such specimens appear, then you are preserving the very genes that make such birds less than the “fittest” birds. In effect, you are weakening your birds. If this weakening by artificial selection is repeated year after year, then eventually you will have a strain of beautiful but weak budgerigars. I am sure that no breeder ever intends to weaken his stock in this way, but it is a major pitfall made by many breeders of many different forms of livestock.

Fertility is Paramount

Many breeders will, no doubt, blame in-breeding for the loss of fertility in livestock (and plants also), but inbreeding, in itself, is not the problem. The problem lies in the fact that fertility is always an after-thought, when things start to go wrong. When selecting your breeding team, fertility is paramount and should come before every other feature for which you are selecting.It is a pointless exercise to pair two beautiful birds to produce no offspring. It is far better to produce over a dozen offspring, of slightly lesser quality, rather than one or two per pairing; you can at least improve upon the lesser-quality birds by selecting the best from a fertile strain.

The problem of poor fertility that seems to affect most studs in Britain, would occur from the fanciers who have the most desirable budgerigars, selling their “culls” to other fanciers. If those “culls” are being disposed of as a result of known poor fertility, (but obviously unknown by the purchaser), then the low fertility genes will be passed on to the next stud and so on. The purchaser, having paid a lot of money for Mr X’s birds will persevere with such poor breeding birds because, visually, they are superior to his own. The new owner will tend to keep the few offspring from the imported birds and then mate them with his best own-produced birds in order to “improve” his stud’s quality (which it no doubt will do), but unwittingly, the fertility of the stud has now gone down drastically !

Many breeders claim that excellent quality budgerigars naturally have low fertility, and some breeders perversely take a pride in the fact that their birds are “difficult breeders” to prove to t themselves that their birds are of exceptional quality; this is foolishness.

Cull the Culls

If breeders did in fact cull their “culls” rather than sell them to other breeders, and bred for fertility for the next few seasons, then the budgerigar fancy could easily solve its present crisis. If randy cocks were mated to prolific laying hens, and those offspring mated to the “quality” specimens and this procedure repeated each year, then fertility could be improved like any other feature in the exhibition budgerigar.

In the wild budgerigar, the ability to fly is essential. Unfortunately many budgerigar breeders think that this ability is optional. If birds that can’t fly, won’t fly, or don’t fly, do not get this natural exercise then they are unlikely to be bothered to partake in the vigorous act of mating! Breeders often refer to broad shouldered birds as possessing “power”, nothing could be further from the truth if the unfortunate specimens possessing “power” cannot fly!

These birds are the modern equivalent of the dodo, and you don’t see many of those, do you? Why, oh why do some breeders attempt to breed with such birds, isn’t it obvious that they are runts?

In a recent edition of Budgerigar World we were given the tale of a hen that had previously refused to breed for two whole seasons. Is Mother Nature’s message not getting through to this breeder? Even if this hen does now produce offspring, the chances are that the offspring will also possess a gene or genes from this hen that will affect the fertility of the stud as a whole, when they are recombined in distantly-related offspring in future generations. This breeder is making a rod for his own back. No matter how desirable a bird is on looks alone, if fertility is also very low, then such a bird is best forgotten. Ignore this at your peril !

In parallel with the infertility problem in budgerigars today, is the problem of the lack of longevity in many birds. Once again, this problem is probably the result of breeding from birds that have genetic factors that result in short lives. This problem could hardly be attributed to in-breeding using father to daughter matings, or grandfather to grand-daughter matings, since these two generations are probably not alive at the same time, during the period of sexual maturity.

Test the Problem

In order to decide if infertility in your stud lies in the management of your birds, or within the birds themselves, then to test this problem I suggest the following:

Buy 4 pairs of small “typey” budgerigars from your pet shop. Then:

  1. Pair two of the pets hop pairs together.
  2. Pair two of the pet shop cocks to two of your own “average” type hens.
  3. Pair two of your own “average” type cocks to the pet shop hens.
  4. Pair up two of your own “average” type pairs as a control pair making a total of 8 pairs in all.

Analyse the Results

To avoid bias on your part, draw lots for the pairings. Follow your normal routine system of management of breeding pairs, and then analyse the results. If your management is not at fault, then it would be my guess that, your cocks are more likely to fail to produce fertile eggs, rather than the pet shop cocks, and both sets of hens will probably lay eggs if they are in breeding condition.

By way of comparison, the thoroughbred racehorse has the best kept pedigree records of any form of livestock. The original founding stock is a mere 3 stallions and 40 mares; all racehorses alive today are descendants of those 43 horses, and every racehorse can have it’s pedigree traced back to the origin of the breed. Every racehorse is distantly or closely related to every other racehorse in the world. Fertility is not a problem. Racehorses must pass a “survival of the fittest” test, The Racecourse Test, and only the best horses are used for producing the next generation. If an expensive stallion proves to be a producer of poor stock, then he is banished from further breeding activity, despite his initial value; he is removed permanently from the breeding stock. Stallions of poor fertility are not persevered with, since they produce few offspring, and mare owners prefer to breed foals! Male thoroughbreds have a strong sex-drive and because of this, at least 90% of males are permanently excluded from procreating by castration. There are very few “genetic ailments” within the thoroughbred population, and weaklings are ruthlessly culled.

The Lesson is there

Furthermore, the thoroughbred racehorse can run considerably faster than any of the original founding stock that have provided the total “gene pool” of today’s racehorses. Over the centuries breeders have found and proved, time and again, that severe selection criteria, coupled with ruthless culling, is the way to produce improvements in livestock, and to maintain those improvements for generation after generation. The lesson is there for all to see; it can be done.

Original text Copyright 1996, Dr John Pilkington

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