It starts at 2am, an unearthly chorus of high-pitched wails that wraps the forest in a suffocating embrace.

It’s as if the indri, the largest living lemurs, are singing at the door of my simple rainforest lodge in the lowland jungle of eastern Madagascar. In reality, they could be as far as 4km away.

Unique to Madagascar, lemurs are some of the oldest primates in the world, and their survival is thanks mainly to the isolation of this ‘lost continent’ which drifted away from the African mainland 160 million years ago. The last inhabited place in the world, Madagascar’s been home to man for just 2,000 years.

The island is vast - bigger than the UK — and poor infrastructure can make journeys long and expensive. To save time and money I join a small group tour with adventure specialists Explore, travelling from the north-east to the south-west.

Lemur spotters, locals from the nearby village, race ahead through the dense undergrowth, hoping to find some of the nine lemur species that live here.

I’m amazed at just how close we can get to the animals; a common brown lemur comfortably forages for berries only metres from our feet, while above us a family of indri propel themselves through the trees with an admirable combination of athletic strength and balletic grace. Only the painfully shy but irrisistably cute grey bamboo lemurs are easily frightened.

  • Sarah Marshall travelled as a guest of Explore on their 15-day The Lost Continent tour of Madagascar. Departures from March to November 2013 cost from £2,247 per person including flights, accommodation, guides and most meals. Visit www.explore.co.uk or call 0844 499 0901.