By Will Grant
BBC News, Colombia
Mass tourism has yet to hit Providencia
The Colombian island of Providencia in the Caribbean, which seems the epitome of a tropical paradise, lies on a key drug trafficking route out of Colombia. It is also home to the Black Land Crab whose remarkable annual migration attracts military protection.
There are two traditional sports on Providencia. One is beach horse-racing, where lithe mares are raced up and down the water's edge at breakneck speed along the foam.
The other is cock-fighting where local men place bets on their favourite bird in the violent blur of razored talons that is a Colombian cock-fight. But in early June, there is a third pastime, crab-swerving.
While crab-swerving might sound like the latest Caribbean dance craze, it is in fact a very necessary skill in Providencia.
During their migration week, tens of thousands of Gecarcinus ruricola, or black crabs, emerge from their holes and head down the hillsides to the beach to deposit their eggs in the sea.
As the island's principal mode of transport is moped, so the "crab-swerve" - the last minute dip to the left or right to avoid an oncoming Gecarcinus - was born.
Judging from the number of splayed crab carcasses on the road, some residents of Providencia are evidently better crab-swervers than others.
Wilbur is a highly accomplished crab-swerver having been born on the island 24 years ago.
For a couple of dollars he will give you a lift anywhere on the island, a side job for almost everyone with a motorbike in Providencia, so one night we ask him to take us to see the crabs.
'Crab watch division'
At midnight, we pile onto his moped - You could ask for helmets, but what would be the point?
We drive to the south-eastern corner of the island to view this natural spectacle in all its glory. On route, we are stopped at a military checkpoint.
Thousands of female crabs head to the sea to lay their eggs
The remnants, maybe, of the tight security from the recent presidential election? Perhaps a spot-check to try to stem the constant tide of cocaine passing through this tiny idyll? No. Dressed in crisp military fatigues and carrying automatic rifles, this is "crab watch division" on evening guard duty.
In Caribbean English, the young private tells us the road is closed for the "crabs dem".
Showing a compassion hitherto unknown in the Colombian military, these men - boys, really - will spend the night stopping motorbikes and the occasional pick-up truck from passing this short stretch of ramshackle highway where the heavily pregnant crabs are crossing the road towards the beach.
"The only way through is walking," the soldier says, before sending another unimpressed local driver back round the long route home.
We dismount and head up into the darkness of the deserted highway on foot. But the road is in fact far from deserted. Every two steps there is another huge crab making its maternal dash towards the sea.
'Thousands of crustaceans'
Their black bodies against the orange hue of the street light makes them stand out like so many fat tarantulas on the march, and as you draw close they rise up with their claws open, ready to defend their unborn offspring to the last.
The baby crabs hatch in the sea before returning to land
"They've got to wash that spawn off them," says Wilbur, "either the sea or the rains will do it. That's why they come out tonight. It's the start of the hurricane season."
All the while he is talking, the forest around us rustles with the constant movement of thousands of crustaceans overcoming the obstacles between them and the shore.
Suddenly the rains the crabs had been waiting for came, and we were the ones scuttling for shelter.
The next morning, the same soldiers stop us travelling in the other direction. The ground is awash with thousands of baby crabs, little larger than ants, returning from the sea.
Even the most skilled of crab-swervers could not avoid a massacre among these miniature creatures.
Yet while Providencia, or Old Providence as the Creole residents call it, may feel like paradise, Colombia's problems are rarely far from the surface.
Miss Julia, like Wilbur, has lived in Providencia all her life, but hers has been a much longer life than his.
"I'm 76," she tells me from inside her tumble-down shack where she sells beers and soft drinks to the handful of tourists on the beach. But today, she has only got a few bottles of water to sell.
Two days earlier, some local youths broke in and stole her stock.
Miss Julia remembers when the island started to change, saying the drug trade first became a problem two or three decades ago.
"Pablo Escobar used to come around here," she says, motioning to the white sands around us, claiming she used to cook for the infamous drug baron. Now though, she says, the cocaine trafficking is worse than ever.
She retells a grisly story about some children from the island whose bodies were found dismembered on the mainland, saying "they wanted to get rich in just one day. The youth don't want to work no more."
Looking out to sea, she adds: "Groups of boys go out on a speed-boat and maybe one doesn't come back, two don't come back, or sometimes they're never heard of again."
Then, with a sad smile "it's the way of Providence."
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