will mate and produce offspring in captivity. However, both reciprocal crosses produce sterile hybrid males and females with decreased fertility. There is a clear effect in which types the parents are. The cross P. sungorus male x P. campbelli female will have embryos that grow normally, like both parent species. But the cross between P. campbelli male x P. sungorus female result in overgrowth, leading to embryonic death. Distribution and habitat Campbell's dwarf hamsters inhabit burrows in the steppes and semideserts of central Asia, the Altai mountains, autonomous areas of Tuva, and the Hebei province in northeastern China. A burrow can contain four to six horizontal and vertical tunnels. The tunnels leading to the nesting area can be as deep as below the ground, but are usually deep. The burrows are lined with either dry grass or sheep's wool. They may sometimes share burrows with Daurian pikas, but only in the steppes and semideserts of northern Manchuria. In parts of Mongolia, the hamsters may also share burrows with species of Meriones to save them from digging their own. In Tuva, Campbell's dwarf hamsters have been found living with other hamsters, such as the Chinese striped hamster, the Roborovski hamster, and the long-tailed dwarf hamster. The diets of the three types of hamsters are different to avoid fighting over the same type of food, which is why they live together. Campbell's dwarf hamsters may also live near areas of human civilization. In Mongolia, they may be found in yurts to keep warm during the winter, as they do not have thermoregulation like the Djungarian hamster. They have five main predators: the Eurasian eagle owl, the steppe eagle, the corsac fox, the common kestrel, and the saker falcon. All distribution areas have more females than males, because males are at higher risk from predators, as they cannot move as quickly. Status and conservation This hamster is listed as of Least Concern by the International Union for Conservation of Nature (IUCN). The population and distribution size is large, and no major or widespread threats to the species are known. However, due to the increasing number of livestock in the areas of distribution, such as the steppes of central Asia, some burrows are at a small risk of being destroyed. In arid areas of distribution, the reduction in the number of water sources is also of minor concern status. These hamsters are conserved in