This seems like a really bad idea to me (except for the last part).

I've seen capuchin monkeys eat the fruit of Strychnos, the genus that strychnine comes from. That could be a fairly risky thing for a human being to consume, especially if you happen to eat any of the seeds, then all bets are off.

Many monkey species, especially those that eat leaves (these would be the most common species you'd encounter, at least in the new world) walk a very fine line between eating enough of a given plant to satisfy their energy budget and eating too much and poisoning themselves. A human following their example is likely to end of with a stomach full of undigestible fiber, get sick, or worse. Energetically, you'd probably spend more calories following the monkeys around than you'd gain from any food you'd collect.

Now eating the monkeys, that might be a good idea, but the primates you'd most likely encounter would be in social groups, and once you kill one of them, it will be very hard to kill another from the same group.

I saw a show on monkeys once where a species of monkeys discovered that by eating the wood charcoal from nearby villages they could eat more of a plant that was normally somewhat toxic to them, the charcoal acting as a filter for the toxin.

There are of course variations of this trick. If you can't find a monkey, either a quail or a toucan will do just fine. I have some friends who were in a military survival training mission in the Amazon.. For many days all they were able to find was swamp cabbage (palmito). Then they found a toucan... The monkey trick didn't work because the trees are very very tall.

Energetically, I bet you'd spend more calories following the bird than any calories you'd gain from food you collect. On the other hand, I've been told that toucan is quite tasty.

Although, once you found the locations you could remember them or map them and then later trips would be more efficient.

Yes, but that probably isn't enough of a savings. We don't have a toucan's digestive system, and can't process large amounts of fruit quickly through our digestive tract like they can. It's a case of starving with a full stomach.

They're in the Amazon, not Soviet Russia.

I wonder why they spend so much time eating nasty things like larvae in these courses. There's lots of fish in the Amazon. Snakes and lizards are quite tasty too. I guess it must be the easiest thing to catch.