In late spring on the open range, ewes give birth outside when the weather is warmer with very little assistance. Depending on the terrain of the ranch, a shepherd will move the flock to a winter pasture that has a lot of natural coverage such as sagebrush or rocky out coves. If a ranch does not have a lot of natural coverage, shepherds may use small teepees to temporarily shelter the mother and her lamb or have lambing shelters strategically placed throughout the pasture. Ewes lambing during severe weather are put into small canvas teepees, along with their newborn lambs, and left there for about 24 hours before turning them out to pasture. The teepees are insurance against death losses occurring from chilling during cold, rainy, or snowy weather and aid in bonding the lamb and ewe. Only strong ewes and lambs survive on the range.