CHAPTER IX. 



BREEDING AND INBREEDING FOR COLOR IN SOME DOMESTIC PIGEONS. 



In the mating of individuals of essentially the same breed of common pigeons 

 there can sometimes be obtained evidence that white and red color tend to appear 

 mostly in the later offspring of the season. From the very first effort of the season 

 also, particularly when immature birds are used as parents, these colors are rel- 

 atively frequent. "Weak germs" are equally responsible for the white or red in 

 both cases. In many cases these striking color variants show other abnormalities 

 or marks of physical degeneracy. The several agencies or factors other than season 

 which similarly affect color, fertility, and sex are also prominent in some of the 

 several series of matings brought together here. Fortunately, the author has 

 written rather fully of the causes of weakness of many of the offspring of these 

 matings; throughout this chapter these statements by the author are given the 

 form of quotations. 



The common pigeons most studied were homers, barbs, pouters, owls, and 

 common rocks. Three or four crosses of these forms with nearly related wild 

 species have been added for the sake of completeness and in order to supply the 

 original data for the fertility and sex summaries of Chapter II. It need scarcely be 

 remarked that here, as elsewhere, all of the data available, not a selected part of 

 it, is presented. 



COLOR AND WEAKNESS IN HOMERS.i 



The results of mating a pair of common pigeons during a part of 3 years are 

 presented in table 70. The last pair of eggs, from each of the two included autumns, 

 hatched birds with much more of white color than was present in any of the birds 

 hatched from the earlier part of the season. Two of these young are shown with 

 their parents in plate 14. The whitened birds of the second autumn were followed 

 in the succeeding year by birds of normal color. The very earliest egg of the second 

 season, moreover, hatched a bird (No. 5) of fairly normal plumage, but its weakness 

 was revealed by breeding. This male E 1 (or No. 5, hatched January 15, 1909, of 

 the progeny of table 70), was mated in May 1909 with a female homer, hatched 

 November 15, 1908. It will be noted that this male came from cf red guinea x 

 9 black guinea, and that, as stated by the author, "both of its parents were strong"^ 

 birds; but this young male (5) had one white primary and three white primary 

 coverts (the latter in both wings), and came at the beginning of the season of 1909. 

 At the time of getting his first young this male had, therefore, nothing to indicate 

 weakness, except that he was only 6 months old. His breeding power should be 

 highest at the age of 3 to 6 years. The female {E) with which E 1 was mated 

 came from an old but strong homer (a few chequers). Her dam was a light gray 

 two-barred homer, that had one drooping wing affected with tuberctdosis in the joint. 

 The points of weakness in the dam of E were, then, lateness in season and tubercu- 

 losis, difficulty in flight, and death in May following. 



» A mating of mongrel common pigeons whose progeny were crossed with homers is more conveniently presented 

 here than elsewhere. — Editor. 



' It is elsewhere noted that this bird (and some of her brothers and sisters) had "frills" in some feathers of the 

 wing tpl. 71, Vol. I) and that this often acoompanies weakness. — Editor. 



