>>Actually the Burmese case of producing female offspring was noted as rare. I think more often it's been documented in snakes to produce only males.

>>

>>Snakes are like birds and exactly opposite of mammals on gender determination. The female snake is zw and the male is zz. So it's the female that has the mixed chromosomes and determines the gender of the offspring with her contribution. Apparently most examples of parthenogenesis in snakes are like that leucistic water moccasin producing males. Not sure but thought I read that for that more common type half of the female's contribution gets doubled up to make a fully homozygous baby right down to the zz (the ww doubled ups don't survive as invalid).



You're right, depending on the species and the mechanism involved it may or may not be an all-female litter. I think, though, that members of a species or a closely related species are likely to utilize the same mechanism as each other. In any case, it at least seems safe to say that a litter of mixed sexes is not a parthenogenetic one!
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0.1 Peruvian rainbow boa (Amaru)

2.0 Brazilian rainbow boas (Arco, Olho)

0.3 Honduran milksnakes (Chicchan, Chanir, Hari)

1.0 Thayeri kingsnake (Coatl)

2.7 corns (Cetto, Tolosa, Uce, TBA)

1,000,000.1,000,000 other critters

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