When thinking of movement in Amazonia, river transport probably comes to mind. Being home to the longest river in the world, with countless tributaries, it is certainly true that a myriad boats - ranging from dugout canoes to narrow peke-peke speedboats to luxury cruise ships - ply the waterways, carrying people and supplies.

And yet, when you step out of the airport in Iquitos, Tarapoto, Pucallpa, or any city in Peru's Amazon, you will be struck by the sight - and sound - of another form of transport: the mototaxi, which will generally outnumber cars by at least five to one.