How do you compare the adrenalin rush of a face-to-face underwater encounter with a great white shark with a fleeting glimpse of a critically endangered Sumatran rhino? Or how can you compare sitting quietly next to a bright red flower, mesmerised by fast-living hummingbirds in their iridescent suits, with the spectacle of millions of monarch butterflies at their winter roost?
This is the great pleasure of wildlife watching: every encounter is different. But it made picking the best of the best – my personal selection of the hotspots that have made the greatest impact on me over 30 years of travelling the world in search of wildlife – particularly difficult. Here is a selection.
Rubbing shoulders with mountain gorillas, Uganda
It's only a one-hour encounter – and there is an awful lot of travelling and trekking to be done beforehand. But rubbing shoulders with wild mountain gorillas is likely to be one of the most emotional, humbling and exhilarating 60 minutes of your life.
There are currently about 800 mountain gorillas left in Africa: 480 in the Virunga volcanoes, which straddle Uganda, Rwanda and the Democratic Republic of Congo (DRC), and some 310-340 in Bwindi Impenetrable Forest, Uganda.
In Bwindi, an island of 128 square miles of equatorial rainforest, surrounded by plantations, the Uganda Wildlife Authority has habituated seven gorilla families to receive human visitors. These consist of as few as seven animals to as many as 36, led by a mature male or "silverback" along with his harem of several females, various immature "blackback" males, and youngsters.
The trek in can take anything from less than an hour, if you're lucky, to as long as 11 hours, if you're not. It all depends on where your allotted gorilla family happens to be at the time.
Within minutes of entering the forest you are sweating and panting, crawling and clambering your way along slippery paths and precipitous mountain tracks. But the moment you come face-to-face with your first gorilla, the mud, the sweat and the tears are a distant memory. Standing in the heart of a seemingly limitless jungle, with a family of the largest primates in the world, is one of life's greatest pleasures.
How to do it
Gorilla treks operate year-round. Fly to Entebbe, then drive to Bwindi. There are several lodges, tented camps, community rooms and campgrounds in Buhoma, near the park headquarters. Gorilla-watching permits for each trek needs to be booked in advance.
Leaping with lemurs, Madagascar
When it decided to slip away from the ancient mega-continent of Gondwana some 160 million years ago, Madagascar unwittingly made a good tactical move. The new island, roughly the size of France, travelled a couple of hundred miles east before settling off the coast of southern Africa. There, while the rest of the world grappled with the emergence of Homo sapiens, it was able to develop completely unscathed.
Visiting this chip off the old Gondwana block is rather like landing on another planet. The plants and animals are vaguely familiar — they resemble monkeys, hedgehogs and civets, for example — yet they are actually lemurs, tenrecs and jabadys. What's happened is that in Madagascar, evolution has come up with different solutions to the same problems as elsewhere in the world. More than 80 per cent of the wildlife inhabiting the 1,000-mile-long island — including every single native terrestrial mammal — is unique to Madagascar.
The undisputed stars are lemurs. No fewer than 100 different species are currently recognised. They are found nowhere else, apart from small populations of introduced mongoose and black lemurs in the nearby Comoros Islands. They range in size from diminutive mouse lemurs (the smallest primates in the world) to indris (the size of large monkeys).
There are two species on the top of ever