Lop Nur is home to the wild Bactrian camel, which is a separate species from the Bactrian camel. The camels have continued to breed naturally despite the nuclear testing. China signed the Comprehensive Nuclear-Test-Ban Treaty in 1996 but did not ratify it. Subsequently, the camels were classified as an endangered species on the IUCN Red List. Since the cessation of nuclear testing at Lop Nur, human incursions into the area have caused a decline in the camel population. Wild Bactrian camels have been classified as critically endangered since 2002 and approximately half of the 1400 remaining wild Bactrian camels live on the former Lop Nur test base, which has been designated the Lop Nur Wild Camel National Nature Reserve.