Size of active vocabulary in hunter gather tribes

Active vocabulary size is a very difficult thing to measure or estimate. Is it all the words ever used in a lifetime or words routinely used? How about homonyms and polysemous words? How about functional words and languages that don't have many?

Another problematic term is 'hunter gatherers'? Do you mean modern hunter gatherers or historical ones? Do you mean small "uncontacted" tribes or large seminomadic societies with mixed modes of subsistence and extensive use of imported technology (think Aleut using snowmobiles).

When people mention hunter gatherers they usually mean small far-away tribes with minimal external contact. However, these are quite likely not to be very representative of what might have been typical before the encroachment of technologically superior belligerent cultures into their habitats resulting in societies under stress whose language may be under all sorts of pressure.

However, despite all that. The actual vocabulary size of somebody in a small relatively isolated community is not likely to be that much smaller than somebody of similar socioeconomic status living in an industrial society. Remember, hunter gatherer lives are not particularly simple. They tend to have knowledge of large folk taxonomies of plants and animals that can go into the hundreds or thousands. They are also likely to have quite complex kin and clan terminology as well as names for various tools and their uses. They might also have an extensive meteorological vocabulary dealing with seasons, parts of day, etc. They will not lack vocabulary for abstract concepts either. In some such societies, people will also have to deal with taboos resulting in name changes as a result of death. And many of them are also likely to be multilingual due to various influences such as intermarriage or other types of contact.

There will also be some variation among individuals depending on their role in knowledge maintenance, etc.