The Pantanal is the largest tropical wetland on Earth, a plain in western Brazil that goes four-fifths underwater every summer, and it is the one place where a jaguar is not a matter of luck. Everywhere else the cat is a glimpse through leaves. Here it lies full length on an open sandbank in daylight, so untroubled that your boat can hold position a few metres off; two or three days on the rivers and you will probably see one. The reason is the flatness. Rain falling from November has nowhere to run on ground this level, so it spreads sideways instead, creeping south for months and lifting the water two to five metres. From June it drains away, and everything that lives here is pulled in around the shrinking rivers and pools rather than scattered under cover.
The boats work the Cuiabá and the Três Irmãos near Porto Jofre, radios passing sightings between them, and on a good outing you watch a jaguar slide off the bank into the water after a caiman. It will not run short of them. Something like ten million yacaré caimans live here, the densest gathering of crocodilians anywhere. In the dry months they pack the drying pools jaw to tail, mouths held open to cool, so thick that the mud seems to move when they do. The way in is the Transpantaneira, which takes you 147 kilometres south from Poconé on dirt, over more than a hundred wooden bridges. It is a safari in itself: caimans under the planks, capybaras on the verge, hawks and toucans in the roadside trees, and over the marshes the wetland's outsized birds — deep-blue hyacinth macaws, jabiru storks, flocks of white egrets. The best hour is the last one. Nothing on that horizon cuts the day short, so the light spreads the full width of the sky while the day's birds cross back overhead to roost.