Over the years, I have at various times worked and /or traveled in tropical jungle environments (Brazil, Colombia, West Africa) and at one time I spent 1/2 a year geological mapping in a remote jungle location in Sierra Leone. That was before the civil war tore that country apart, I was living in a canvas tent and spent the entire rainy season back there in the jungle. It was hot and humid all the time. I could write a book about all the stuff that went on there: voodoo, black magic, witchcraft, poisonous snakes, large constrictors, swarms of army ants, un-paid army and police foraging off the countryside, etc. etc.
Anyway the take away about photography in the jungle is that heavy overcast days are your friend, take advantage of those days. Bright, sunny days will be challenging to the extreme to get good shots. I was shooting Kodachrome 64 back then with, what maybe 8 stops of dynamic range, so you will be a lot better off with digital today. Use rain covers to keep the rain off your cameras and for protection from water dripping off the tree canopy, which goes on for hours after it stops raining. The rain/humidity will eventually destroy your camera and lenses if your are there for any length of time. For a short visit, seal your cameras and lenses in plastic bags with desiccant packs at night to dry them out. If your camera has some weather sealing, store it in with the battery door and other doors, i.e. cards slots, etc. open to allow the humidity to leave the camera. When I returned home to Vancouver, my Nikon F3 was toast, I sold it for parts and my lenses all had fungus growing in them; I threw one away and sold the others for $25 each. In the end, I got a few OK pictures but the heat/humidity had caused the film to go off a bit so they are challenging to scan and colour correct and I haven't really done very much with them.