Rurre is well set up, with multiple tour companies offering jungle and pampas tours. I hadn't booked anything in advance, but it wasn't a problem, and the next day I found myself on a boat with a 5 other travellers heading up the Rio Beni into the Madidi National Park.
A lot of what you actually see in the jungle in practice is plants and insects, and a few birds. The vegetation is dense and offers lots of cover to the many animals that live there. But some of the plants are amazing. We were astonished by the "walking palm", which has one trunk for most of its height, but for the lower 1-3 metres, has lots of sub-trunks to support it. As the top moves to find light, more sub-trunks are sprouted to support the weight, while older ones die off, leading to the tree gradually (on the scale of a few metres every few years).
Then there are the trees which start off high up in the canopy, and grow downwards, such as the vines which form real creepers you can swing on. And the "strangler fig", which acts as a parasite, gradually encompassing and killing off the tree it leeches on to. There are numerous types of tree where you can't tell where it started, and how it formed the shape it now has. A "Queen's Seat" formed a strong branch looping down which was easily strong enough to sit on.
We did a number of night walks to find creatures of the night... on the first night, we saw a "Night Monkey", with its eyes reflecting our torchlight. And tarantulas, everywhere. A particularly large one lived in among some "motacu" fruit. And one lived in the roof of the cabin where I was sleeping.
An afternoon's walk took us to a campsite in the jungle, well situated to see the colourful macaws the next morning. We then (with a lot of help from our guide) quickly built a raft and floated downstream back to the jungle lodge. This was slightly marred for me by the fact that some cash was stolen from a bag that I left to be taken by boat back to the lodge... The boat-driver and the cook were the only two people who saw me take the cash out of my wallet (to avoid it getting wet), and then had access to it for an hour or two...
The two days we spent in the pampas gave us the opportunity to see many more animals, however. Loads of capybaras and caimans on the river bank, pink river dolphins all around us, a large variety of birds, several species of monkey, and on the last day, an anaconda. In hindsight, the guide picking up this anaconda and then handing it round to us was not really the right thing to do from an ecological point of view...
On my return to Rurrenabaque, I had a relaxing day before taking a flight back out to La Paz. I took the opportunity to walk along the river and find a place with few currents where I could swim... all alone. Two German-speaking girls (who nevertheless claimed to be Bolivian) I met on the path later turned out to be working in the restaurant I had a great meal in that evening.