The largest controlled breeding experiment with canaries, conducted 70 years ago under the auspices of William Bateson (F. M. Durham and D. C. E. Marryat, 1908. Royal Society of London, Reports to the Evolution Committee, Report 4: 57–60.), involved 1300 birds with either black or pink eye color. The difference is governed by two alleles at the Z-linked cinnamon locus. Crosses between pink-eyed males (bb) and black-eyed females (BW) produced unexpected pink sons and black daughters that are attributed to primary nondisjunction in meiosis II of spermatogenesis. Several interdependent estimates of the incidence of nondisjunction progeny range up to 16 ± 3%. Cytological evidence is lacking for Durham's (F. M. Durham. 1926. J. Get. 17: 19–32.) and other presumptive nondisjunction cases in the contemporary literature comprising canaries, doves, and pigeons.
Experiments in HeredityReport I to the Evolution Committee, Royal Society. W. Bateson , E. R. Saunders