I don't know the average lifespan, but what I have heard how highly variable life spans of populations are in rainforest locations ranging from well below that of here in north america to even higher than here for some. diet and lifestyle habits locally are responsible for variations of this in rainforests. Whole villages have the same lifespan because all residents share the same common habits, so when they are bad such as only eating starchy roots, drinking or something else, it reflects in the whole population there. I won't adopt any othat stuff. I know the key to a long healthy life is things like green vegetables, activity ect and it may be hard to convince them of that. avoidance is the most important preventitive measure I plan to use against health problems in the Amazon. Also the plants such as antifungal, bacterial, viral ect. can also be used to further strenthen prevention on any suspected exposure to health threats like applying them to disinfect after photographing animals in a wetland. I have bought an infatable boat which makes it easy to stay seperate from threats in wetlands and still take photos. lets hope a piranha or spiny animal does not pop it!