A novel PCR‐based genetic marker shows that sex of offspring does not account for hatch‐order effects on growth, survival and dominance in Pūkeko Porphyrio melanotus melanotus

摘要: Intra-brood competition can influence a variety of fitness-related traits in birds. Previous research on the joint-nesting Pūkeko Porphyrio melanotus melanotus, New Zealand subspecies Australasian Swamphen, showed that chicks hatched earlier brood tended to grow faster, were more likely survive and had higher dominance status as adults than later nest-mates. However, this finding could be due changes offspring sex ratio across hatch order (e.g. if males tend earlier), which was not previously examined because methodological challenges associated with sexing nestling Pūkeko. Here, we report useful PCR-based genetic marker determine We then used new sex-specific data re-examine patterns growth, survival dominance. found does account for hatching-order related social dominance, growth or survival. Furthermore, negligible ratios did differ significantly between primary female secondary broods (in joint-clutch nests), when comparing single broods. no clear evidence bias according conclude explain survivorship adult