A couple of days ago we (Pap et al.) submitted a manuscript for review in Evolutionary Ecology. This paper searches for parasite traits (prevalence, abundance, dispersal capacity, subpopulation size) that could explain the extent to which sex ratio is distorted towards females and how this might affect sexual size dimorphism and feeding efficiency of three Ischnoceran lice species. To this end, around 30 adult house sparrows (1:1 male:female) were sampled across 16 Romanian populations.