CHITWAN, Nepal - All hell broke loose as the one-horned rhino stepped out of the crate, the powerful male charging elephant-mounted mahouts relocating him to a new home in Nepal's far west in the hope of shoring up the vulnerable species.

The cantankerous male - whose single horn keeps him in the crosshairs of wildlife poachers - is the first to be relocated to Shuklaphanta National Park but will be joined by four females of breeding age.

Finding suitable rhinos for the ambitious relocation program is a marathon effort for the 100-strong team.

Atop elephants they set off at dawn in Chitwan National Park, communicating in brief shouts and hand signals as they fan out across the plain and into the dense jungle.

Thousands of one-horned rhinos once roamed the southern plains of Nepal but rampant poaching and pressures of human encroachment reduced their numbers to around 100 in the later part of last century.

A successful anti-poaching and conservation initiative has seen the population steadily climb over the past decade to around 645.

But new blood was needed in Shuklaphanta National Park, currently home to about eight rhinos, to protect the country's population against threats, said Doctor Kanchan Thapa, a biologist from conservation group WWF.

A female is the first rhino spotted - a prime candidate - but as she emerges from the dense bush, a calf of about 9 months follows her out.

Her calf - which will stay with its mother until it is around 2 years old - counts her out of the move. The search continues.

More than three hours later, an excited whisper goes around as another rhino is spotted: a huge male.

The elephants encircle it, slowly encouraging him toward a marksman waiting perched in a tree with a tranquilizer dart gun.

It is a painstaking process: one wrong move could startle the 2-ton male into charging the elephants or slipping back into the forest.

He moves slowly toward the open plain where the marksman waits, almost veering out of range before coming to a stop within striking distance.

The dart hits the rhino in its flank. It breaks into a run but his lumbering strides gradually slow until he falls to his knees about 100 meters away.

The vets attach a satellite collar around his neck and take blood samples before a dozen men roll him onto a sledge. A tractor is needed to shift him into a crate before the convoy begins a 15-hour overnight journey to his new home.

Anticipation builds as the crate is opened, revealing the vast backside of a sleeping rhino. Despite the long journey, he initially appears reluctant to budge.

But he suddenly springs to life and charges the truck, butting it a few times with his horn before turning his attention to three elephants standing nearby.

The rhino leaves a deep gash on the backside of one elephant, panicking the beasts as the mahouts on top try to regain calm. The rhino stormed into the forest and out of sight, leaving a cloud of dust in its wake.