Less than a day. This vast open border is where the South African rangers have to stop their protection work and Mozambique, poor after decades of civil war, doesn't have the resources to protect them. Local men are paid a pittance to take the risks and kill the animals, while the middle men and sellers in the Far East make a fortune on the horns and tusks of the dead rhino and elephants.
How can it be stopped? Its not the fault of the local villagers, desperate to make a living for their families. Education, financial compensation for damage to crops and helping communities benefit from the wildlife's presence are all crucial long-term goals.
In the short-term the wildlife needs protection, the most effective being the dog squads that can track poachers during the day or night. Its not easy work - such a squad was recently attacked by villagers, paid by poachers to remove them. But the work must continue.
Using dogs has allowed rangers to work at night, previously impossible as they need their eyes to track, not their noses. Before, the poachers could move with impunity during darkness, now they cannot because of the skill of the dogs and their handlers.