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Many bird fanciers shy away from genetics, thinking it is too complicated. Any subject turns out to be complicated; but some people learn to be comfortable with portions. Occasional additions then are more platable. Its the same with genetics. Like any topic it can be presented in more than one way. For ringneck genetics one way is a series, so you wont get too big a bite at any one time. Lets start with colors, since color is what most people have and interest in.
A standard of reference is important. I choose to use the wild type = standard type = "normal" which is dark color. This the color found in S. semitorquata, or S. decaocto, or S. roseogrisea, the ancestor of our domestic ringneck.
Dark collared doves have a deep red eye, if they are kept outdoors subject to the solar radiation, or even if they are kept indoors and subjected to ultra violet light. Eyes of blond doves are also red, barely a shade lighter? Indoors the eye is a bit lighter red.
Plumage of the dark dove may be described as dark gray, Evidently, no one has investigated the pigments involved in doves. However, very likely two types are involved in the plumage and eye color - - the eumelanin, black-browns, and phaeomelanin, red-yellows. These are very widespread among most all vertebrates.
The gray plumage of dark doves becomes blackish in the neck ring, in the flight feathers and in the tail bar. Likely, the phaeomelanin is missing there. This notion is supported by the orange mutant (see Miller and Munsell, p. 5 Nov/Dec ADAN, 1985 issue), The tips of the tail feathers, especially toward the side (less in the middle ones) become whitish with no melanin or very little present. Juvenile dark doves and even blonds show a buff edge lacing that is most noticable in the wing shield coverts. This is lost in the adult plumage. A whitish trailing edge to some flight and secondary wing feathers is also seen. For a fuller description see Goodwin, D. , 1977, "Pigeons and Doves of the World".
To reiterate, the wild color in the collared dove is gray from the mixture of various amounts of eumelanin and phaeomelanin. All the color varieties are mutant forms of various alterations, patterns, dilutions, and/or blocking of one or the other of these pigments. A diagram of the biochemical synthetic pathway could show where an early block of the path by an abberrant or missing enzyme such as tyrosine hydroxylase will result in albino. Dove and pigeon albinos might be a result of a second block, since the first is involved also in the adrenaline pathway.
A summary of the basic single color mutants and some of their combinational interactions are shown in the following figure.
This color originally occurred in Japan. It was described by Tange, 1932, 1949. Dr. Hollander and I imported it in 1967 from Dr. Takao Kashiwabara, Dept. of Animal Husbandry, Fac. of Agric. Ibaraki University, Tsuchiura, Japan. He sent us 3 males and 3 females, but evidently they were so inbred that they failed to produce a pure bred strain. Only after outcrosses with our ringnecks did we reextract the albino with high fertility. This was the source of my J strain of birds and all albino ringnecks in the U.S., so far as I know.
By definition, albino is the absence of melanin. In some species other pigments such as xanthophylls or carotonoids are present. An albino red-winged black birds, for example, could have red and yellow epaulets. But in the ringneck dove and domestic pigeons also, feather and eye pigments are only melanin, so they are white with pink eyes.
The albino squab when first hatched is difficult to distinguish from white, or even from the ivory-rosy = cream combination.
My studies confirm Tanges results that albino is a regular (autosomal) recessive in inheritance. My evidence is presented in table 1. Note that I classified 1,905 squabs from 153 matings for albinism. A statistically significant excess (less than P = .05) of albino progeny occurs twice among 10 kinds of matings. Chance with small numbers is probably the explanation for the first of these ( Probablility = P = .04). I have no explanation for the second which has larger numbers (P = .017). From 153 matings 1905 offspring were classified from purebred matings, from first crosses, from testcrosses, and from F2 (carrier by carrier) matings.
Doves that are carriers ("split"= heterozygotes) of albino may have some albino offspring. In fact, on the average, 1/4 of the offspring would be albino. If we use al to = the albino gene and + to = the alternative normal gene (allele) it can be diagrammed like the figures below. (For the gene symbol some persons may prefer just the "a" for the albino gene symbol, or c = colorless used in some other species. Also remember that an individual has 2 a gene for any one character, but sperm or eggs have only one.)
Albinos certainly cant see as well as normal birds. They dont like really bright light. If kept outdoors, they are likely to develop eye problems sooner than other types might. The main difficulty, however, is with squabs. In common with whites and combined mutants like creams whose eye pigment is slower to develop than other types, they are less able to find food and water readily. The fancier needs to recognize thirst and hunger and assist the squabs for 1-2-3 days. Of course, other colored squabs may have water and food probems, but, in frequency of needs, albinos are often the most helpless. Once adapted to the food and watercups, they do very well for themselves.
Tange, M. 1932 Unexpected occurrence of albino individuals in the offspring of blond ring doves, Streptopelia risoria. (In Japanese with an English resume). Japanese Jour. Genetics, 8: 1-18.
Tange, M.ü 1949 Further data on the crossing of albino ring doves with white ones. Journal Fac. Agric. Kyüshü University 9: 127-142.
The species hybrids are between S. risoria and S. humilis [dwarf turtle dove] with (usually) several backcrosses to risoria, but often mated inter se as well.
The ivory mutant color presumably on the blond background was described by Taibel, 1966, in Italy in Atti della Societa Italina di Scienze Naturali e del Museo Civica di Milano Vol. 105 Fasc II: 158-174. We know of no importations. In tracing back to the origin of our stock, we find that the same phenotype turned up in Rayne, Louisiana. Julius Thidodeaux was described as an elderly chap who kept doves in one large pen. Thidodeaux was the source of ivory doves raised by Frank Webb in Port Arthur, Texas as well as by Ron Young of Huston. Webb was the source of ivory doves to Richard Burger of Newark, Delaware. And Burger donated 4 ivory doves (one male and three females) to us 3 May 1971.
Taibel, 1969, also published on the dark ivory as I interpret it. Taibel called it pearl ash, and got it by crossing with another species, S. decipiens and reextracting it (Natura-Soc. It. Sc. Nat. Civ. St. Nat. e Acquario Civ., Milano 60/1:32-40 15-II.). The eyes are noticeably lighter than normal. Closer examination makes evident a rather finely mottled appearance of the iris, of the red to light or no pigment.
Juvenile ivory doves (as with rosy juveniles) closely resemble blonds. Their forehead feathers are distinctly lighter, and the tail bar centrally bleached, but less noticeable than in the adult.
Ivory plumage appears to have a dilution effect similar to blond. Ivory is less "brown", or is a bit more "gray", than a blond. The primaries (remiges) appear more dilute in ivory than in blond and have a more pronounced white tip to the primaries, which is barely detectable in the dark wild-type and slight in the blond. The primary coverts show a tiny stippling effect of dilute pigment versus almost no pigment as do the primaries themselves in the middle of the feather. This is especially noticeable in those primaries near the middle of the wing. The stippling is more marked on the leading edge of the feather. the secondaries appear quite free of the stippling.
The rectrices or main tail feathers have the tail "band" or pigmented area lightened centrally. The lightened area is not so much stippled as in the wings but more bleached, much as in recessive opal of pigeons. See Miller, 1976 Pigeon Science and Genetics Newsletter 2:24. Dr. W. F. Hollander and myself obtained a cross of such and opal pigeon with and ivory dove. The offspring was normal. Therefore, these mutants are non-allelic.
The breeding results or family data that I collected agrees with Taibels. My demonstration of recessive inheritance for ivory involved classifying 1,063 progeny of 8 kinds of matings, (table 2 in ADAN Nov-Dec 84). The ivory class is consistently deficient in numbers although accepatable for the statistical test of chi-square. But one type of mating (P=.027) was statistically, significantly different from expected. This may be explained by misclassification as hatchlings which died early preventing correction in the older squeaker. Or, perhaps, ivory homozygotes are detrimental during incubation. Or a combinatin of these is possible. Also chance might be involved. The reciprocal cross is as expected, and when combined yields a tolerable chi-square value (X2) of 3.42.
The motting of the eye can be called a pleiotrophic effect of the ivory gene. Genetically, pleiotrophy is the action of a single gene that results in more than one kind of detectable effect, often without obvious causal reasons. For example, blue eyed, white furred cats are usually deaf. The deafness has no obvious relation to the white fur or blue eyes, but one gene controls the total difference from normal cats. Similarly the ivory gene also controls mottling ofl the eye. Originally I thought ivory also controlled a very light color down (about white) on newly hatched squabs. I found that white down separated alone, which is not possible with pleiotrophic genes. Therefore, I am dubious that ivory always must have whitish down in the squab.
Interactions: Ivory on a blond background yields a blackish collared very light colored bird. The black half collar is diluted a bit more in blond-ivory birds than in ivory or blonds, but not noticeably so with a superficial glance. This light ivory also may be called show-ivory, since fanciers prefer it somewhat to the ivory on a dark background (the single mutant form). Ivory combined with rosy yields a "heavy cream" or light tan bird. If blond is included it is a light cream. Cream is a very attractive, even beautiful color, pied ivory is as most would expect. Perhaps we should leave fuller descriptions of interactions to a later section.
Genetic diagramming: Genetic symbol manipulation is practically identical to that for albino. By the way, the slash mark in the albino diagrams stands for the chromosome which is then tagged by the + or al gene. [You may wish to reduce the al symbol to a in diagramming. The slash may be omitted also, if you remember that there are always two chromosomes, therefore, two genes in the indivudual for any one simple character. Similarly the ivory gene iv may be reducd to just i to save a little clutter.]
Table 2. Breeding results of the ivory plumage color mutant in various mating systems in the ringneck dove, Streptopelia risoria.
Genetics of the Ringneck dove, Streptopelia risoria.
IV. Description of mutants - pied - autosomal recessive - pi.
[ADAN Jan-Feb 1985: 9-11]
Pied of mottled or splashed "variants" have been known and occasionally reported in doves for many years; for example, Finn, 1902 (Journal of the Asiatic Society of Bengal, pages 162, 167) and Dr. Oscar Riddle, 1947, (Endocrines and Constitution in Doves and Pigeons. Carnegie Institution of Washington, Publication 572 - see plate 3, p. 15.) However, nothing particular came of them until about 1957, when Bernard Roer of Phoenix, Arizona, first bred some, and later started selling them. Heres what he has written about the origin:"
"My pied Ringneck doves were first raised by Mr. Hugh Nichols, Higley, Arizona, from a pair of common Ringnecks that he got from me. They had about half pied young (male and female). These were mated together and raised only pied. At about this time pied birds were raised from Ringnecks byd Lou Shoemaker in Baldwin Park, California. These birds looked like the ones we had. I sent a lot of my doves to California, so they have been mixed."
One piebald or pied female dove and 3 carriers were first sent to us by Richard Burger of Newark, Delaware about 20 May 67. Two years later he sent 9 unsexed pied that matured into 5 male and 4 female pieds (plus 4 carriers).
No bill ring nor bill pigment is seen in the newly hatched pied, although very rarely it might appear "by chance". I think I have noticed it twice in about 600 pied hatchings; but it was more a small "blob" than a ring. The juvenile plumage of pied doves looks much like grizzle pigeons with streaks of light or no color merging with pigmented areas on each feather. The next or adult plumage is distinctly different. Each whole feather is normally pigmented, or is white (not pigmented). Patches of pigmented feathers or non-pigmented feathers are scattered, at first glance seemingly at random. Then one notes some tendency to pattern or regularity of the pied areas. Some birds are mostly white with only a few pigmented feathers. More rarely some birds are mostly pigmented with only a few white areas. This tends to follow family lines, and is obviously genetically influenced. Since the mostly or more white birds were common among pied birds, I selected in the reverse direction. Most of my pied stock now has much pigment.
The pattern or regularity of white patches shows up best in such mostly pigmented birds. The face and throat seem to be one center of white patching. the wing butts or shield area by the wrist is another center of white patching. The rump, flights and tail are progressively involved in white patching as the extent of white patching increases. One curious feature is that the tail "bar" of pigmented feathers on pied birds is disturbed. The pigment seems to "run" further out towards the tips and smear into a "rusty" tone so that the neat (discrete) "bar" pattern effect is lost.
Carrier or heterozyous pied birds may have one or a few white feathers, especially on the head. This happens with about 10% (9.86) of such birds, and is diagnostic for carriers if present. Such flecked head plumage may represent somatic mutation. (White feathers from scars are pretty rare, but could mislead someone on rare occasions. )
In pied doves the orange-red eye ring is missing. The eye color is "black". Since the pupil is unaffected, the actual color is "dark ruby", a blackish iris with a red pupil, depending on age. In dove squabs the eye ball is so large and the position of left and right eyes so nearly opposite that light can be seen through the pupil from the opposite side of the head. This is almost true for the adult.
Pied doves combined with the sex-linked white are white with black eyes. The white is obviously epistatic to (hides) the pigmented feathers. But the black eye of pied shows that effect also on white doves, hence, back eye whites. All other color combinations are as one would expect. Regular pied (dark), peach pied and peaches and cream likely will be favorites with fanciers; but blond pied, rosy pied, and pied ivory wll have their place.
Genetic diagraming can follow the same style given for albino and ivory characters (ADAN Sep-Oct, Nov-Dec 84). [Again you may wish to shorten the pi gene symbol to p.] The normal gene (non-pied) can be Pi+ or just +. The plus, +, in genetics is the symbol for the normal, standard, or wild type gene. Some students like to use + as a superscript to the gene, but it is not necessary to do so. For the diagram model this time Ill just use the F2 and emphasize the phenotypic-genotypic shorthand form. Note that the + _ includes purebred normals and carriers.
In analyzing the inheritance of pied, I classified 1,986 birds, see table 3. My ringneck test cross data exhibited a very rare event -- i.e. a "perfect" ratio of 291:291 non-pieds to pieds when we expect a 1:1 ratio here. The testcrosses with male hybrids, however, and pooled male plus female hybrids had a significant deficiency of pied progeny. I have no clue to the reason for this, except that species hybrid populations are more likely to have their chromosome pairing and segregation to be abnormal. Indeed, such data may b evidence for such abnormalities. Cytogeneticists are unwilling to look for this directly, because bird chromosomes are so small.
Genetics of the Ringneck dove,
V. Description of Mutants - Rosy-autosomal recessive - ry.
ADAN Sep-Oct 85 : 4-8
Rosy doves are reddish. Their head is "mauve". Thus, they give a two-toned effect of very attractive coloring. This color evidently has less of the eumelanin or dark pigment, but this needs confirmation.
Rosy was first brought to our attention in 1960 when Reed Kinzer of Lancaster, Penn. inquired of Dr. Hollander about them. Mr. Kinzer wrote on 6 Mar 61 calling them dilutes or rosy. "I got them from George Kleinpell of Cleveland, who in turn got them originally from a man in Cleveland who has nothing but this type." On 12 December 62 Kinzer sent to Dr. Hollander 6 young by RR Express. They matured into 4 males and 2 females. Three of the first crosses were to the wild type dark.
Rosy was reextracted on the dark background. The first such dove was 114L in my records, a male dark rosy, D+ dB ry ry which hatched on 14 Feb 64. Often such squabs are difficult to distinguish from blond until about 6 weeks of age when the mauve color starts to show well on the forehead.
Most fanciers first encounter rosy on the blond background. Various names were proposed besides rosy, including salmon, peach and cream. Peach finally won out, since rosy fit the dark background better and cream was a little too extreme. I suspected that cream as a name might fit a combination of ivory
and rosy better. This was verified later. Moreover, the mutant should be named after the single mutant form (i.e. rosy on a dark background). Blond (= dilute) rosy is peach, which is a double mutant. Actually, different parts of a ripe peach would fit either dark or blond rosy in color.
Rosy fits a monohybrid Mendelian situation, see table 4. However, there is evidently a deficiency of rosy progeny, enough to reach significance generally when over a hundred offspring are classified. The only exceptions are with humilis species-hybrids. In all there were 2,658 progeny from 258 matings classified in tests with rosy. We have no indication that dark rosy squabs die off faster then blond rosies after hatching or vice versa. Perhaps rosy dies off faster in embryo; however, preliminary results in "Reproductive Success Indices" do not support this notion either. This could turn out to be an example of "meiotic drive" -- a rare phenomenon in genetics.
There is an alternative explanation. Some rosies vary from one another in the degree of color. More specifically, some adult (dark) rosy birds are difficult to distinguish from blond without side by side comparisons. A genetic modifier seems indicated, since it "runs in families". I have tried to indicate such birds in my own records as r ry instead of ry ry. This might also fit McClintocks controlling elements" in corn (= maize) for which she recently got the Nobel Prize. Controlling elements are also called transposons or plasmids in bacteria and they are involved in "genetic engineering". Such might explain the deficiency of rosy progeny. Wouldnt it be ironic to find such esoteric or sophisticated phenomenon in the dove fancy!
This color is pictured in color in a 1982 article by Alois Münst in "Lachtauben in vielen Farben" Geflugel-Börse (No. 23) 103:12-13. He pictures blond pied, dark, blond, and what I take to be blond ivory, dark ivory-rosy = heavy cream, and orange. Orange looks much like a peach (blond, rosy) with a whitish neck ring which I have produced more than once in my stock. This orange also has very light flights and tail (like blond rosy?).
Orange was imported into Canada about 1982 and soon thereafter into the United States. Genetic tests to differentiate orange from blond rosy evidently have not yet been made.
The blond rosy has already been described as "peach". White hides rosies except for the main under tail. The ventral tail feathers of white rosy doves have the eumelanin "band" much reduced over that showing in the white bird. One has to look closely to see it at all. Therefore, it was named clear white. Pied rosy is attractive, especially peach pied with patches of color (peach) and no color as expected. Ivory rosy combination is called heavy cream, perhaps the most attractive new color to turn up in doves.
The blond-ivory-rosy (light cream) is nice too, but it is so light that novices have to look twice to notice the neck ring to distinguish it from white. Evidently the ivory mutant doesnt block all the phaeomelanin, nor the rosy block all the eumelanin as does happen in yellow-chinchilla rabbits or silver-pyle chickens to yield a mimic white. Unfortunately no one has tested ringneck doves to see if they have both melanins for sure.
Recent data has implied that rosy modifies the color of "split" blond/white males (heterozygotes) more than to the expected peach. They look similar to (mimic) cream or even blond ivory. That is, they are lighter in color than peach females. This is a possible source of confusion for color types.
Those who have been following my diagraming, well might be able to just substitute the gene symbol ry and diagram the same results as for the other colors. Last time for pied I gave an F2 kind of result. So this time Ill give a testcrosss (T.C.):
Im sure some of you would like to have the difference between rosy and peach diagrammed. Since it depends on the dark versus a blond background, and since these are sex-linked, we ought to wait until sex-linkage is explained a bit first.
Table 4. Family data for the inheritance of the rosy color mutant in ringneck doves.
Dove color genotypes phenotypes, Origins of ringnecks, Stubby dwarf ringnecks, Minerals, mourning dove, Dove are delightful, Genetics of Ringnecks, Absence of Bill Ring, Feral pigeons, Advances in Classical Genetics
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