It is late morning in April, during green season, in the little-known Tarangire National Park, the secret gem of northern Tanzania. Our guide is a big Maasai chap called Godwill (also known as Godwin), whose voice has all the effortless volume and carry of an experienced guide, from years of shouting facts into the back of his vehicle. He slows down as a small herd of impala bounds from our path into the thick grass. We do not stop for them; it is only the second day here, but the golden-coloured antelope with their long twirling horns comprise two out of three of all animals we have seen so far. However, moments later, as we drive along the edge of the park’s famous and extensive swamp, I can feel myself being flung forward in my seat as Godwill firmly applies the brakes, a sure sign he has seen something good.