Even for wildlife lovers, Brazil's Pantanal wetlands are overwhelming. Eagles and hawks sit on every other gate post and the blue sky is filled with the raucous calls of thousands of brightly coloured parrots. Giant anteaters, armour-plated armadillos and herds of white-tailed deer roam the grasslands take shade under brilliantly coloured trumpet flower trees. And gullies, streams and rivers seem to overflow with crocodile-like caiman.

The wetlands are also the best place in the world for seeing that most elusive of all big cats, the jaguar - the new world's apex predator. Jaguars look a little like leopards. In pictures. But in real life they are almost twice the size, with a bite more powerful than a Bengal tiger. They are also far, far harder to see. For decades jaguars have been harder to find than snow leopards, with film crews spending months on end in the wilds of South America with little more than a glimpse. Until now.

Our Brazilian friend Ailton has been tracking jaguars since he was a boy. No one knows better where to find them. And now he has agreed to show them to Tell Tale travellers.

Ailton's trips leave from his designated safari camp built in the heart of the Pantanal. Metre long indigo Hyacinth macaws nest in the camp, near Ailton's tents. Ocelots and crab-eating foxes wander between the tents at night. After waking at dawn, to the trill of tanagers, and the staccato call of the chacalaca - a turkey sized forest bird, the journey begins, with a sedate boat ride on the beautiful Cuiabá river.

There is wildlife everywhere. Capybara - which look like giant guinea pigs on stilts - burst from the river banks into the water, huge jabiru storks flap lazily through the air and capuchin monkeys gaze inquisitively down from trees by the river bank.

After an hour or so the boat enters the heart of the Pantanal wilderness and the Cuiabá splits into smaller streams. There are no sounds but the babble of the river and the call of the birds and the air is so clean you can see for miles. Wildlife becomes even more exuberant and almost entirely fearless of humans. Two metre-long giant otters cavort around the boat like puppies. Herons stab at fish a few feet from the bow, kingfishers flit in and out of the trees.

Ailton searches the banks for jaguars. The cats rest here in the shade during the day, or enter the rivers and streams for a cooling swim. At dusk they hunt, ambushing capybara or hoiking caiman out of the water with a single paw. We heard the jaguars many times, letting out deep, throbbing calls - like the bark of a giant dog.

And then in the late afternoon we finally saw a jaguar. She was lazing under the shade of a fruit tree, a few metres from our boat - so at ease she seemed to be smiling from her deep green eyes - revelling in her magnificence as we excitedly took photographs and felt the adrenaline rush surge through our veins.

Spot jaguars for yourself on our very special Brazil trips.