American Pigeon Journal
December 1990, page 33.
From Domestic Pigeons
By Robert J. Mangile
816 E. Atkinson Ave.
Pittsburg, Kansas 66762
Every
now and then, one reads about a pigeon fancier who discovers that he or
she has a female pigeon that occasionally lays a three-egg
clutch. This puzzles many fanciers because the normal clutch size
for domestic pigeons is two eggs.
In a 1977 Pigeon Science and Genetics Newsletter, [PS&GN] (issue #4, page 45) Tom McCaig of Hacienda Hts., California, wrote that a particular black crested Frillback hen laid 3-egg clutches "every time" that year and all three eggs were fertile. Her sister also laid 3-egg clutches twice that year. A hereditary basis was implicated.
In keeping with traditional ‘newsletter spirit’, I responded to McCaig’s comments (PS&GN, issue #5, page 29), with the following: "....3-egg laying hens. No secret, I don't think!? I had one. This bird was a double-yolk layer. I supposed this was the case on a couple of 3-egg clutches and reported it somewhere in PGNL [Pigeon Genetics News Letter] some time ago. Apparently, two ova that ordinarily comprise a double-yolked egg are encased separately. Anyway I did get a few double-yolked eggs out of her later. If more details are desired I'll run down my records - OK? The bird was a blue Runt hen."
Dave Rinehart (PS&GN editor) responded with: ". . (OK - run them down Bob! I have a red Lebanon hen that repeatedly lays double yolked eggs: but she has never laid 3-eggs. No accurate records kept on how many clutches or how many double yolked eggs she produced though. Seemed like about every other nesting though. - Dave)"
On page 12 of PS&GN, issue #6, selected data on my Runt was published. To summarize, on October 26, 1972, she laid two soft, rough-shelled eggs, followed by another normal egg on October 30th. In other words, ... a ‘3-egg clutch.’ (Note the time between eggs?) Following that three-egg clutch, she laid a minimum of six (6) clutches of one normal egg and one double-yolked egg through December 1974. In short, each clutch contained three yolks!? Primarily, they were recorded in the fall and winter months. No records of double-yolked or three-egg clutches were recorded during the spring and mid-summer months.
Many fanciers have long held the idea that the double-yolk egg-laying trait is hereditary. Hens that lay double-yolked eggs can sometimes be traced to other double-yolk egg-layers in their pedigree. This is tricky at best because long held stock is often inter-related anyway!
In "The Pigeon" (Chapter IV – Physiology, paragraph 443), W.M. Levi mentions abnormalities of clutches. He states . . . "The pigeon hen usually lays two eggs to the clutch; in rare cases, three; and occasionally, only one. The latter is caused by the improper functioning of the hen's reproductive organs. Very rarely are four eggs laid to the clutch."
In paragraphs 444 and 445, he discusses hatching difficulties for identical twins (normal size eggs with one yolk shared by both embryos) and double-yolked twins (large eggs containing two separate yolks and embryos). One case mentioned was of a ‘normal-downed’ and a ‘short-downed’ squab within a single shell. The differences in down length suggest that each squab was derived from a separate fertilized egg (yolk). Twin squabs rarely hatch without human assistance.
R.G. Silson (1988, Jour. of Heredity) reports on hens that lay three-egg clutches and suggested that the 3-egg clutch trait was a simple recessive mutant. He states . . . "A pedigree study indicates that the factor is a simple recessive that is not fully expressed in the homozygote. All later three-egg hens always had a three-egg hen on both sides of their pedigree, sometimes several generations back."
Nothing solid can be concluded without more detailed study. Hens that lay three-egg clutches are possibly double-yolk layers that occasionally or frequently lay three eggs due to the intended ‘double yolks’ being encased in separate shells. The same would hold true of the 4-egg clutch; i.e., both [sets of] eggs were intended as double-yolked.
Whether or not the double-yolked characteristic naturally has modified expressions and/or can be modified into three-egg or four-egg laying hens through selection, is questionable at this time. If any consistency can be recorded from selected pairings in related birds that lay multi-egg clutches, perhaps we can establish a genetic unit to 'multi-egg clutches' and through selective breeding change the reproductive mode of domesticated pigeons. This might be achieved more easily than one might expect.
In a 1977 Pigeon Science and Genetics Newsletter, [PS&GN] (issue #4, page 45) Tom McCaig of Hacienda Hts., California, wrote that a particular black crested Frillback hen laid 3-egg clutches "every time" that year and all three eggs were fertile. Her sister also laid 3-egg clutches twice that year. A hereditary basis was implicated.
In keeping with traditional ‘newsletter spirit’, I responded to McCaig’s comments (PS&GN, issue #5, page 29), with the following: "....3-egg laying hens. No secret, I don't think!? I had one. This bird was a double-yolk layer. I supposed this was the case on a couple of 3-egg clutches and reported it somewhere in PGNL [Pigeon Genetics News Letter] some time ago. Apparently, two ova that ordinarily comprise a double-yolked egg are encased separately. Anyway I did get a few double-yolked eggs out of her later. If more details are desired I'll run down my records - OK? The bird was a blue Runt hen."
Dave Rinehart (PS&GN editor) responded with: ". . (OK - run them down Bob! I have a red Lebanon hen that repeatedly lays double yolked eggs: but she has never laid 3-eggs. No accurate records kept on how many clutches or how many double yolked eggs she produced though. Seemed like about every other nesting though. - Dave)"
On page 12 of PS&GN, issue #6, selected data on my Runt was published. To summarize, on October 26, 1972, she laid two soft, rough-shelled eggs, followed by another normal egg on October 30th. In other words, ... a ‘3-egg clutch.’ (Note the time between eggs?) Following that three-egg clutch, she laid a minimum of six (6) clutches of one normal egg and one double-yolked egg through December 1974. In short, each clutch contained three yolks!? Primarily, they were recorded in the fall and winter months. No records of double-yolked or three-egg clutches were recorded during the spring and mid-summer months.
Many fanciers have long held the idea that the double-yolk egg-laying trait is hereditary. Hens that lay double-yolked eggs can sometimes be traced to other double-yolk egg-layers in their pedigree. This is tricky at best because long held stock is often inter-related anyway!
In "The Pigeon" (Chapter IV – Physiology, paragraph 443), W.M. Levi mentions abnormalities of clutches. He states . . . "The pigeon hen usually lays two eggs to the clutch; in rare cases, three; and occasionally, only one. The latter is caused by the improper functioning of the hen's reproductive organs. Very rarely are four eggs laid to the clutch."
In paragraphs 444 and 445, he discusses hatching difficulties for identical twins (normal size eggs with one yolk shared by both embryos) and double-yolked twins (large eggs containing two separate yolks and embryos). One case mentioned was of a ‘normal-downed’ and a ‘short-downed’ squab within a single shell. The differences in down length suggest that each squab was derived from a separate fertilized egg (yolk). Twin squabs rarely hatch without human assistance.
R.G. Silson (1988, Jour. of Heredity) reports on hens that lay three-egg clutches and suggested that the 3-egg clutch trait was a simple recessive mutant. He states . . . "A pedigree study indicates that the factor is a simple recessive that is not fully expressed in the homozygote. All later three-egg hens always had a three-egg hen on both sides of their pedigree, sometimes several generations back."
Nothing solid can be concluded without more detailed study. Hens that lay three-egg clutches are possibly double-yolk layers that occasionally or frequently lay three eggs due to the intended ‘double yolks’ being encased in separate shells. The same would hold true of the 4-egg clutch; i.e., both [sets of] eggs were intended as double-yolked.
Whether or not the double-yolked characteristic naturally has modified expressions and/or can be modified into three-egg or four-egg laying hens through selection, is questionable at this time. If any consistency can be recorded from selected pairings in related birds that lay multi-egg clutches, perhaps we can establish a genetic unit to 'multi-egg clutches' and through selective breeding change the reproductive mode of domesticated pigeons. This might be achieved more easily than one might expect.
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