Treasure hunting in Tobago

It's 6am and we're heading off into the rainforest. The temperature has already reached 32C and the sun is still rising. According to our guide, this is the best time to catch a glimpse of the forest's colourful birdlife.

Forget about coming to the Caribbean to lie on a beach.

Here, at the northern end of the island of Tobago, we are on dawn safari. Peter Cox, our sharp-eyed guide, is one of Tobago's leading birders and it doesn't take long before he stops and points up into the dense tree tops. At first it's impossible to see anything through the thick mass of branches, but suddenly I spot a beautiful scarlet-plumed tanager perched on a branch.

As the morning progresses, and the heat rises, we see a pair of brightly coloured parrots swoop between the trees and a giant blue emperor butterfly that flutters by as we rest at a waterfall.

Hopping over streams, ducking under fallen trees and scrambling up ridges, we make our way deeper into the rainforest. The occasional heavy downpour keeps the oppressive humidity at bay, and lessens the sense that we're walking through a steam room.

The best is saved for last - a hummingbird sitting on a tiny nest. It looks fragile enough to be blown away by a breeze. We hold our breath as it waits for a few seconds, then with wings flapping like helicopter rotor blades, it darts off in search of food.

If you're looking for a beach holiday with a difference, Tobago is the place to go. The island has strings of pristine white sand beaches and tempting remote bays, but it's also a paradise for eco-lovers. The rainforest is 60 million years old and covers more than 14,000 acres. The oldest legally protected rainforest in the western hemisphere, it's home to more diverse flora and fauna than anywhere else in the Caribbean.

The eco-diversity is due to the island's proximity to South America, and its strange history. One hundred million years ago Tobago was in the Pacific, part of a chain of volcanic islands. As the continents moved around, it was nudged east to the north coast of Venezuela. In the last ice age, sea levels fell and continental plants and animals migrated here, only to be trapped when the waters rose again.

Interestingly, Tobago now shares certain species of wildlife with northern Venezuela that don't even exist in neighbouring Trinidad. There are more than 250 species of birds, in an island just 26 miles long and seven miles wide, and animals from armadillos and agoutis to racoons and opossums.

Another reason why the Tobagan rainforest intrigues scientists and laymen alike is how it has regenerated since Hurricane Flora in 1963. As much as 75% of the forest was damaged, but in the intervening years trees and plants have revived to form a thick replacement canopy now more than 150ft high.

A lush island, Tobago is awash with colour, from the orchids, heliconia and hibiscus tumbling over garden walls to the fruit orchards and cocoa plantations of the interior. And you can enjoy much of it undisturbed - Tobago is often overlooked by holidaymakers seeking Caribbean breaks, meaning no tourist hordes and reasonable prices.

There is plenty to do on the island and in the surrounding Caribbean sea. Spend a few hours snorkelling or take a trip in a glass-bottom boat to Buccoo reef, where parrot fish, angel fish and reef sharks float in and out of the coral reef and underwater canyons.

For divers, the waters - which contain every species of hard coral and most of the soft varieties - are largely unexplored and are so clear that underwater visibility is almost unrivalled at 130 to 150ft.

If you prefer your water shallow, you can wade out to sea for a mile and still be standing waist-deep, on top of the sandbank at Nylon Pool.

Reminders of the island's colonial past are never far away and Tobago is dotted with places named by homesick British governors - from Plymouth and Scarborough to Speyside and Culloden.

Over the summer and up until the end of September is turtle season on Tobago, when people gather to watch, from a distance, as the turtles lumber ashore to lay their eggs.

The giant leatherbacks - more than 6ft long and weighing up to 600lb - are now an endangered species. They swim from the warm waters of the Caribbean across the Atlantic and back again feeding on jellyfish. When they are ready they return to the beaches where they were hatched to nest.

Underwater, these vast creatures move as fast as torpedoes and can even outswim sharks. But they're at their most vulnerable for the couple of hours it takes to clamber up the beach, dig a hole in the sand and lay eggs. Huge and cumbersome, they look positively prehistoric.

A local conservation group protects the turtles from poachers but it's a constant battle on an island where turtles have been historically killed for their meat.

For something completely different, don't miss the races - goats and crab, that is. Jockeys run behind their goats in the races in Scarborough while locals study form and place bets on their favourites. The crab races are much more leisurely -it can take more than an hour for the crustaceans to reach the finish line of the 10ft long course.

For another taste of local life, there's nothing like the food. Kingfish, mahi mahi, cassava, sweet potatoes and the Tobago favourite, curried crab and dumpling, are on just about every menu.

Wherever you go on on this laid-back island, the palm trees sway to the sounds of soca and calypso music. A party called Sunday School in Buccoo village is the place to practise your dance moves with the locals. The beach event spills out onto the surrounding streets and sound systems belt out music till the small hours.

While all this is going on, just a short distance along the beach turtles come ashore to nest - to the sound of crashing waves and calypso. Only in the Caribbean.

Details: A week at Rex Resorts Turtle Beach costs from £699, flying from Gatwick (Golden Caribbean, 0870 777 6922, www.goldencaribbean.com).

British Airways and British Midland fly from Glasgow and Edinburgh to Gatwick, with fares starting at £55.

A full-day rainforest trek with Peter Cox of Tobago Nature Tours costs from £60 (e-mail peter@tobagonaturetours.com or see www.tobagonaturetours.com).