I started raising and flying pigeons in June 2007 and created this website to share my research and my experience about the pigeons. I was very reluctant, however, to start writing about pigeon genetics because it can be a very complicated subject to most people. I am a computer science teacher and biology has always been one of my favorite subjects. I am neither a scientist nor a geneticist, I am just a curious, albeit serious pigeon breeder and I would like to understand as much as I can about my hobby to produce better quality offspring. I have been experimenting with genetics, but most of the information on this page comes from research I've done on the internet, books, and my interaction with other pigeon breeders. This is not a comprehensive work intended to cover all aspects on the subject of pigeon genetics, but instead help pigeon fanciers understand how genetics work. My intentions are simply to explain the basics of pigeon genetics to fanciers, so they can more appreciate the hobby and breed better quality of pigeons and colors they like. I am hoping that it will help some of you better understand your hobby and answer some of your questions.

Basic Genetics

In order to better understand the pigeon genetics you have to understand basic genetics and genetic terms first. I think it would be easier to start with human genetics that we are most familiar with then transit into pigeon genetics like mutation, colors, and patterns, etc.

We are all made out of cells, and each cell in the human body contains about 25,000 to 35,000 genes. Genes are a set of instructions that decide what the organism is like, how it survives, and how it behaves in its environment. Genes carry information that determines each person’s traits. Traits are characteristics humans inherit from their parents, such as the color of the hair, the color of the skin, the color of the eyes, likelihood to develop certain diseases etc. All living things have genes.

Genes are all lined up on thread-like things called chromosomes which come in pairs, and there are hundreds, sometimes thousands, of genes in one chromosome. The chromosomes and genes are made of DNA (left picture), which is short for deoxyribonucleic acid. DNA molecules are the long-term storage of information that is often compared to a set of blueprints or a code, since it contains the instructions needed to construct other components of cells. The DNA of humans is composed of approximately 3 billion base pairs, making up a total of almost a meter-long stretch of DNA in every cell in our bodies.

In humans, a cell nucleus contains 23 pairs of chromosomes, which are 46 individual chromosomes. Half of these chromosomes come from one parent and half come from the other parent. But not every living thing has 46 chromosomes inside of its cells. A pigeon has 40 pairs of chromosomes, which means pigeons have 80 individual chromosomes.

Each gene has more than one form of expression. For instance, an eye color gene can have the two different forms of expression of orange eyes or bull eyes in pigeons. These forms of expressions are called alleles or allelomorphs. Each pair of alleles generally has a dominant allele and a recessive allele. In the presence of the dominant allele, the recessive allele does not express itself. The only time that the recessive trait will be seen is when both of the alleles are recessive. In genetics, dominance describes a relationship between different forms (alleles) of a gene at a particular physical location (locus) on a chromosome. Typical plants and animals have two sets of chromosomes, one set inherited from each parent, and are described as diploid. They, therefore, have two alleles, each from one parent, at each gene locus.

If the two alleles at the same gene locus are identical, the individual is called a homozygote for that trait and is said to be homozygous; if instead the two alleles are different, the individual is a heterozygote and is heterozygous. When the trait is homozygous, the phenotype is what both alleles represent. If it is heterozygous, then the two alleles interact, and the dominant one is the one that shows as the phenotype (the actual trait that you see on the animal or plant, such as "ash red" color in pigeons). Hemizygous gene has no allelic counterpart or is present as only a single copy instead of the usual two copies in a diploid cell or organism. In other words, a gene wherein one of its pair is deleted is a hemizygous gene. In another example, most of the genes of the X chromosome and Y chromosome in human males are hemizygous since males have only one X chromosome (and one Y chromosome) (unlike females that has two X chromosomes).

An autosome is a chromosome that is not a sex chromosome – that is to say there are an equal number of copies of the chromosome in males and females. In humans, there are 22 pairs of autosomes, and in addition there are X and Y chromosomes which are sex chromosomes. In the picture shown on the right, two chromosomes X and Y, are used to represent and determine the sex of a human offspring. Male is represented by X and Y chromosome symbols and female is represented by two X chromosome symbols. In reproduction, each parent submits one chromosome for the child. A female's egg always contains an X chromosome, never a Y, because all of her chromosomes are XX. The male's sperm, however can contain either an X or a Y. If the male sperm that joins the egg happens to contain an X chromosome, then it will join from the X of the mother, making the child female (XX). But if the male sperm that joins the egg happens to contain a Y chromosome, the child will be male (XY). In this manner, parental genes decide whether the offspring will be male or female. This also means the gender ratio in humans is 50% male and 50% female. It is very important to understand that in humans, the male's chromosomes determine the sex of the offspring.

In pigeons, the female's chromosome determines the sex of the offspring because female pigeons are hemizygous for color, hence carrying only one color. Genetically, all male pigeons carry two colors, one we see and one that is hidden. The dominant color is the one that is expressed (that we see, assumning the bird is heterozygous for color). Females on the other hand, carry one color and one empty color allele. This means every female pigeon carries only the color that we see on the outside. This is very important to understand because unlike humans, the sex of the offspring is determined by the female's chromosomes. Cock birds carry two colors, and will donate one of them during mating. If the hen donates the color she carries, then the offspring will have two colors, each donated by a parent, and will make that bird a cock bird. If the hen does not donate a color (the empty allele), the offspring will have only one color, donated from the father, and will be a hen. You will understand why this is so important in the next page when I explain the pigeon colors and sex-linked mating among pigeons.

Mutation in Pigeons & Human Interaction

Before I get into pigeon colors and patterns I would like to talk about one more thing, and that is mutation. The ancestor to our domestic pigeons, the rock-dove (Columba livia), is considered to be the wild type in pigeon genetics. It is a blue bar with no crest and has clean legs. The wild type does not have any heavy skin above the beak or around the eyes and has a pale grey color with two black bars on each wing. Columba livia is found everywhere in the world as the same type and size and it is the original type and standard against which we compare any mutation. Pigeons are found almost everywhere on Earth; however, they don’t occur in very cold places or in very dry places. There are no native pigeons on the Hawaiian Islands or on the islands of the mid-Atlantic ridge. The genetic symbol for wild type is (+).

But how did we get so many different breeds of pigeons from the rock-dove pigeons? How did we get breeds like jacobins, pouters, barbs and rollers? When and what went wrong for these mutations to happen? Did humans play a role to create so many different pigeon breeds?

According to Charles Darwin, this is called the Selection of Traits. In order for existence, survival and reproduction do not come down to pure chance. Darwin realized that if an animal has some trait that helps it to withstand the environment better or to breed more successfully, it will leave more offspring behind than others. On average, the trait will become more common in the following generations. As Darwin studied natural selection, he spent a great deal of time with pigeon breeders, learning their methods. He found their work to be an analogy for evolution. A pigeon breeder selected individual birds to reproduce in order to produce a front crest. Similarly, nature unconsciously “selects” individuals better suited to surviving their local conditions, because those who are not as well adapted die off when the ones with an advantageous trait may survive because of that trait. Given enough time, Darwin argued, mutation and natural selection might produce new types of body parts, from wings to beaks. With more than four thousand years of breeding behind them, domestic pigeons are full of combinations deemed beautiful or useful, or both, by their breeders.

The varieties of pigeons we see today are from the odd mutations that man noticed and liked it, then bred the trait into his flock to intensify it. While man was attempting to create new breed from an odd mutation, which would normally not have survived in the wild, nature used natural selection to ensure that the fittest and the strongest survived. Mutation is not a random event. Those mutations that allow the organism to survive and leave more offspring are preferentially accumulated within the gene pool; those that don't are preferentially removed (along with the animal bearing them). Variation in the wild is a necessity that allows for adaptation, which in turn encourages survival. Darwin thought that we don’t see mutations like fan tails, pouters, jacobins, feathered feet and crest in the wild because they would not have survived in the wild on their own. Human played a big role for these mutations to be evolved and perfected over time.

How do we prove that all the fancy pigeons today came from Columba Livia, the rock dove? When Darwin was studying pigeons, and wrote his “The origin of Species”, he devoted the whole first chapter to the domestication of pigeons. He discovered that if the different fancy breeds are mated, the off spring would eventually lose their distinctive traits and resemble the rock dove. Darwin called this phenomenon “reversion”. According to Darwin there was no other reasonable explanation for the profusion of fancy pigeons, and he was right. Many pigeon breeders, who have been around pigeons for long time experience a reversion even in a certain pigeon breed, where two distinct colors and patterns are bred and their offspring show the markings and the color of an ordinary rock dove.

The first images of pigeons found by archaeologists in Mesopotamia (modern Iraq) date back to 3000 BC. In all the ancient civilizations, from early Mesopotamia through Greece, Egypt and Rome rock doves had their admirers, breeders and keepers. Once man started city states between the Tigris and Euphrates, a lot more grain was needed to be grown and harvested than it used to be to feed all the citizens of the city. The rock doves took advantage of that extra seed and grain found around the cities and bred more profusely. We know that pigeons will continue to breed as long as a good food supply is available. Man in turn, took advantage of the rock doves themselves and climbed the cliffs and rocks to collect the eggs and squabs for food. Although a fairly timid bird in the wild, if taken when young, pigeons showed a tendency to be domesticated providing a regular source of food during difficult times. It was the Sumerians in Mesopotamia that first started to breed white doves from the wild pigeons. Pigeons have been domesticated for thousands of years for their roles in human lives as symbols of gods and goddesses, sacrificial victims, messengers, pets, food and even war heroes. Pigeons and doves have been immortalized in poetry and prose, music and art.

The white pigeons have been recognized as a symbol of love, peace and a new beginning. In many cultures, white doves represent the Holy Spirit and the soul and are further symbolic of hope, innocence, tenderness and purity. Ancient and modern civilizations fly white doves in ceremonies celebrating devotion, partnership and fertility. In a lot of Middle Eastern countries the pigeon droppings was used as a fertilizer and later as gun powders by the Turks. The rock dove’s ability to find home from a distance was noticed by man quickly and they have been kept for sending messages back home from war zones and distant cities. The ones which have the more talent and the body type to come home fastest have been interbreed to produce better quality birds for generations. Man has always been a collector and quick to spot the unusual so he would have noticed the odd white feathered bird and as time passed these odd birds would have been spared and then interbred to produce more varied and unusual birds. After many years of domestication and man's selective breeding, variety of talents (fast flying, endurance flying, tumbling, rolling, diving, singing, etc.) various colors, shapes and sizes developed all for human pleasure and needs. Now, all over the world, thousands of pigeon lovers and breeders from all different backgrounds have a great bond of brotherhood because of their common interest - the pigeon.

"Just what it is that makes one love pigeons is hard to analyze. Some seem born with this love an inherit part of them. They acquire their birds in their early youth and never part with them; others commence their rearing at a later period, and either soon part with them or develop into enthusiastic fanciers. There seems to be no middle ground; one either loves pigeons or one does not. That man is fortunate who finds in his breast an inexplicable love for them. To him, is affordable a hobby of immeasurable value. When fortune frowns and when the cares of a harsh or disordered world seem almost too heavy to bear; when the grim reaper has taken some loved one; or when nerves are tense almost to the breaking point, then the pigeon lover finds in his birds a solace and consolation impossible to describe. When, through some temporal triumph, one is prone to be impressed with his own prowess, then again, by contemplating the ways of the pigeon, the great temperer, one is brought back to the norm. The pigeon proves a stabilizer, leveling the depths of depression and the heights of false ecstasy, as he 'keeps the even tenor of his way,' always happy, always devoted, always indifferent to the vagaries and the tribulations of the human soul. The pigeon lover unwittingly absorbs his calm 'philosophy' " (Wendell Levi, The Pigeon, p. 34).

Studies show that the lifespan of an feral pigeon is only to 3 to 5 years in the “wild”. With proper feed and care, pigeons can live 15 years or more in captivity. There are 309 different species, belonging to the taxonomic family Columbidae. Pigeons are arranged into four subfamilies: typical pigeons, which eat predominantly seeds; fruit pigeons, fruit eaters found in tropical Africa and Asia; crowned pigeons, which have a crest of feathers on the head; and a fourth subfamily containing only one species - the Tooth-billed Pigeon, which has a serrated upper bill. The following pictures are few examples of show type breeds that we have today. They are all developed and mutated with the help and careful selection of humans for more than four thousand years of breeding and domesticating the rock doves for variety of reasons.