Dawn over the karst hills of Guilin.
These remarkable hills owe their peculiar shapes to the mildly acid waters of the Li River,
whose meandering course over eons of time has corroded away their bases
until only the rocky cores remain.
The Li is one of the cleanest rivers in China,
a favourite spot for fishermen with their trained cormorants.
The men, all called Huang, come from the same village. Now in their 70s and 80s,
they've been fishermen all their lives.
Before they release the birds,
they tie a noose loosely around the neck
to stop them swallowing any fish they may catch.