JOHANNESBURG — At a time when mankind’s encroachment on habitats is increasingly leading species to extinction, scientists have discovered a mass migration of animals in Africa that reaches farther than any other documented on the continent.

The journey made by about 2,000 zebra who traveled between Namibia and Botswana, was discovered by wildlife experts only after some of the zebras were collared with tracking devices.

The newfound migration is a rare bright spot at a time when mass movements of wildlife are disappearing because of fencing, land occupation and other human pressures. Species of plants and animals around the planet are being wiped out at least 1,000 times faster than they did before humans arrived on the scene, said a separate study published Thursday by the journal Science.

The previously unheralded trek occurs within the Kavango-Zambezi Transfrontier Conservation Area, which is the size of Sweden and encompasses national parks in Namibia, Botswana, Zimbabwe, Zambia and Angola.

“It goes to show us that nature still has some surprises,” said Robin Naidoo, senior conservation scientist at the Washington-based World Wildlife Fund that led the two-year study on the migration. The zebra odyssey encompasses a roundtrip journey of 300 miles, starting in floodplains near the Namibia-Botswana border.