Because wintering Willow Ptarmigan (Lagopus lagopus) display sex segregation with management implications, we obtained age and sex ratios from 340 hunter-harvested Willow Ptarmigan from 4 winter areas in Labrador: Javelin Mountain 1998–1999 (111 birds), Javelin Mountain 1999–2000 (96 birds), Lobstick Structure 1999–2000 (98 birds), and Mokami Hill 1998–1999 (35 birds). Those data illustrate a considerable age and sex segregation among wintering areas: Lobstick Structure birds were disproportionately male, 70% (46% adult male), Javelin Mountain birds were disproportionately female, 78% in 1998–1999 and 77% in 1999–2000. Mokami Hill, produced sex ratios between those of the other two areas: 69% female. Sex segregation on our wintering areas likely resulted from females dispersing farther from breeding areas than males. Because the climates of Javelin Mountain and Mokami Hill are successively warmer than that of Lobstick Structure, females may be selecting wintering areas that produce higher quality food than areas occupied by males. If Willow Ptarmigan are disproportionately taken from the Javelin Mountain area, then the substantial sex segregation on wintering areas suggests that hunter-harvest can suppress breeding success.