Sure enough, bang on 5am we awoke with an incredible commotion right above our cabin. It sounded like a drunken didgeridoo player but turned out to be howler monkeys.

They were starting their morning routine of moving through the tree tops and marking their territory by shaking and bashing the branches, all while howling as loud and low-pitched as their throats could handle.

Two hours later and after a few menacing confrontations between neighbouring family groups, the larger, darker males decided they had made their point and the howling died down.

Now we could see the smaller females some of which had piggybacking babies. A much more peaceful start to the day as we went into breakfast.

Our guide warned us that they often don't find the elusive anaconda but that mid-morning is our best chance as they slither out of the mud to warm their cold blood in the sun on top of the swamp grass.

So we set off after breakfast for an hour-long boat trip downriver to a particularly swampy part of the pampas. We donned our gumboots and got to (carefully) stomping through the swamp.

It was very hot and hard work but the potential of the big snake kept us going. After an hour of tracing through mud and knee-high water over an area of swamp about two football fields wide we still hadn't found anything. Half an hour later our guide was ready to pack it in but Mateo and I were determined and with the guide we decided to run lines a couple of metres apart, back and forth like a search party.

Just then we found a nice big patch of anaconda poo on top of the mud. It looked just like you'd imagine — large with a scaley pattern . We were on the right track! Another half an hour later we finally found one.

It was a gorgeous Green Anaconda, the most common variety in the Bolivian Amazon and the world's heaviest snake. Ours was almost 3 metres so only mid-sized for a species that officially reaches 6m long and up to 9 or 10 metres in local reports and legends. Specimens that size have been found with unlucky human victims inside and there are a few such tales in the local Yacuma community.

Correction: Thanks to Nick at www.nicksadventuresbolivia.com, it turns out ours was the even rarer Beniano or Endemic Bolivian Anaconda. A smaller species, so ours would have been nearly full-grown.

After pulling it out of the long grass, as gently as possible with a large angry snake, our guide carried it to a more open patch where we could get a good look and follow it for about 20 minutes as it peacefully slithered back to the swamp.

She seemed to be quite content to let us marvel at her beauty and the time we spent right alongside her was well worth the hours in the sun and mud. Another dream come true.