Red-shouldered hawk parents favor female offspring when times are good. New research reveals that, on average, red-shouldered hawks (Buteo lineatus) produce more females than males when resources are plentiful in their environment. In a study published recently in the Journal of Raptor Research, researchers tracked nests across Ohio for three decades. They found that the nests in areas with plenty of resources produced more females than males. They believe this occurs because females require more energy to produce—they grow faster but demand more food. In times when resources are slim, the ratio of male chicks increases, perhaps because the parents can’t spare as much effort to feed so many females.
