During the last century, Africa's black rhino population plummeted by more than 90 percent, reaching an alarming low of just 2,300, but five were recently returned to the Serengeti National Park as part of an ambitious initiative to boost the viability of Tanzania's rhino population.

"Six flights to deliver the rhinos to Serengeti National Park are sponsored by National Fish and Wildlife Foundation, the Nduna Foundation and the Wildlife Without Borders program of the U.S. Fish and Wildlife Service (USFWS).

"The rhinos' safe arrival is a remarkable achievement for rhino conservation and for cooperation between nations, according to the USFWS. During the next two years, a total of 32 eastern black rhinos will be returned as part of the Serengeti Rhino Repatriation Project, more than doubling the number of rhinos in the Serengeti.

"The 32 black rhinos destined for Serengeti National Park are descendants of animals that were taken from Kenya to South Africa in the 1960s. Originally kept in the national parks' estate, they were sold into private hands in the mid-1990s. Meanwhile, in Tanzania, illegal poaching of rhinos decimated the native wild black rhinos.

"In recent decades, increased security efforts on private and public lands have helped black rhinos recover in some parts of East Africa. In preparation for welcoming the returning black rhinos, the Serengeti National Park strengthened security throughout the park and created an elite rhino-protection force trained to safeguard the rhinos and their habitat for years to come."

Learn more at AllAfrica.com.