Rarest hamster

The world's rarest species of hamster is the nowadays ironically named common hamster (Cricetus cricetus). Also known as the European or Eurasian hamster, it was indeed formerly very common, its geographical distribution stretching eastwards from France and Belgium in Western Europe through Central and Eastern Europe to the Altai Mountains and Yenisey River in Asian Russia. Due to intensive trapping for the fur trade and also widespread killing as a farmland pest during the 20th century, however, its numbers have fallen so dramatically through much of its range that the International Union for Conservation of Nature (IUCN) declared it Critically Endangered in July 2020, the first and presently the only hamster species thus designated. Its total number in the wild has not been determined so far, but during the past century its population size has fallen by over 90% in some regions, and both its lifespan and its litter size have decreased markedly too.

Prior to 1930, the rarest hamster species was the golden or Syrian hamster (Mesocricetus auratus), which since its discovery in 1839 had only been known from a handful of specimens captured in its native homeland of Syria and bred for a time in captivity before dying out. In 1930, however, an adult female and her litter of young were captured in Aleppo, Syria, and brought back alive to Jerusalem, where they bred in captivity. Some were then sent to zoos, universities and private individuals around the world in order to found new populations and try to ensure the species' long-term survival, Fortunately, they did continue to breed, ultimately resulting, incredibly, in all of today's millions of specimens maintained worldwide as popular children's pets and also as laboratory animals.