If Madagascar is the kingdom of the weird, then the aye-aye surely wears its crown. Just one glimpse of those bulging orange eyes, naked bats' ears and crooked witches' fingers explains why this creature is, for many islanders, the stuff of the heebie-jeebies.
While locals have long feared the aye-aye as a harbinger of evil, visitors have simply been baffled. The first naturalists concluded from the bushy tail and chisel incisors that it must be some bizarre kind of squirrel. In fact this perfectly harmless, cat-sized creature is – like us – a primate. Specifically, it is a nocturnal lemur and, like all Madagascar's lemurs, found nowhere else on earth.
Weirdest of all are those long fingers – especially the skeletally skinny middle ones. And their function is unique in primates. As the aye-aye clambers around the canopy it taps on dead branches. Should a hollow ring reveal a cavity – and, even better, the rustling of juicy grubs within – it rips off the bark with its teeth and uses these freaky digits to winkle out the prize. Thus on Madagascar the aye-aye fills the slot taken by woodpeckers elsewhere.
Aye-ayes live almost entirely in the rainforest canopy, feeding by night and sleeping by day in a tree-fork nest. Males mark their treetop territories with pungent glandular secretions and during the courtship season sometimes come to blows over females. A desperate suitor may even pull apart a mating couple in the hope of some action for himself.
Seeing this peculiar primate is a challenge. Local people have long persecuted aye-ayes, both because of their association with death and their raids on coconut plantations. The good news, however, is that this elusive mammal is now known to be much more widespread than was once feared.
Sightings are easiest on the island of Nosy Mangabe, where aye-ayes have been reintroduced. Elsewhere – with a good torch, an experienced guide and a large slice of luck – you might come across one at several rainforest reserves, including the well-known Andasibe-Mantadia National Park (Périnet).
* Rainbow Tours (020-7226 1004; rainbowtours.co.uk) offers a two-week tour in search of aye-ayes and other wildlife in Madagsacar's eastern rainforest reserves, including Nosy Mangabe, from £3,880 per person, including flights.
Mike Unwin is the author of '100 Bizarre Animals', published by Bradt Travel Guides (£16.99). Independent readers can purchase the book for only £11.50 including UK p&p via www.bradt-guides.com. Enter coupon code 'mudskipper' at the checkout.