The IUCN's Red List of Threatened Species lists 55 species of Cervidae, 2 of which are listed as extinct and 1 is considered critically endangered. Of the remaining 52 species, 8 are endangered, 16 are vulnerable, and 17 are listed as "least concern". The remaining 10 species are listed as "data deficient". Many more local deer population are on the cusp of extirpation, which could lead to inbreeding in adjacent populations. According to the IUCN, major threats of extinction for cervids includes over exploitation due to hunting, habitat loss (e.g., logging, conversion to agriculture, and landscape development), and resource competition with domestic and invasive animals. In addition, climate change has begun to contract species ranges and forced some species of cervid to move poleward. For example, moose, which are an important ecological component of the boreal ecosystem, are notoriously heat intolerant and are at the southern edge of their circumpolar distribution in the north central United States. Since the mid to late 1980's, demographic studies of this species have revealed sharp population declines at its southernmost distribution in response to increasing temperatures. In addition, climate change has allowed more southerly species to move poleward, which increases competition and disease transmission at range interfaces of various species (e.g., white-tailed deer and moose). Finally, cervids are an important food source for a number of different carnivores. As cervid populations decline, so too will those animals that depend on them. CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) lists 25 species of cervid under appendix I.