Parental investment and sex differences in juvenile mortality in birds and mammals

@article{CluttonBrock1985ParentalIA,
  title={Parental investment and sex differences in juvenile mortality in birds and mammals},
  author={Tim H. Clutton‐Brock and Steve D Albon and Fiona E. Guinness},
  journal={Nature},
  year={1985},
  volume={313},
  pages={131-133}
}
The common finding that juvenile male mammals show higher mortality than females1,2 is usually attributed either to the expression of deleterious recessive alleles on the X chromosome3 or to adaptive manipulation of the postnatal sex ratio by mothers who are unable to rear successful sons4,5. As a general explanation of differential juvenile mortality, the first of these two theories is unsatisfactory because increased male mortality is known to occur in several bird species where females are… 

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