title: Sex ratio and intrasexual kin competition in mammals.
abstract: Asymmetries in both intrasexual competition and generation overlap occur in Antechinus (Dasyuridae; Marsupialia). We show that the range of interpopulation variation in the sex ratio of pouch young spans and exceeds the range of sex ratios at birth hitherto recorded from eutherians (Clutton-Brock and Albon 1983). Although postweaning dispersal and male mortality are similar among all Antechinus populations, interpopulation variance in female longevity leads to variable duration of mother/daughter interaction. As this duration increases, parental investment is increasingly biased toward males, supporting the view that local competition among female kin for resources may influence mammalian sex ratios.
authors.affiliation: Department of Zoology, Australian National University, GPO Box 4, 2601, Canberra, ACT, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Cockburn
authors.affiliation: Museum of Comparative Zoology, Harvard University, 01238, Cambridge, MA, USA.
authors.forename: Michelle P
authors.initials: MP
authors.lastname: Scott
authors.affiliation: Department of Zoology, Australian National University, GPO Box 4, 2601, Canberra, ACT, Australia.
authors.forename: Chris R
authors.initials: CR
authors.lastname: Dickman