In response to your question regarding why men participate in large game
hunting if it is a dangerous , low-yield activity the answer is two fold.

First, in many cases, men are free to particpate in an activity that does
not predictably yield a food resource because the gathering activities of
the other members of thier group produces a sufficient amount of food for
them.  (It should also be noted that hunters will gather food while engaged
in hunting activity, either to feed themselves if the hunt
is long or to bring back to camp.)  For hunter/gatherer peoples that have
not been recently forced into marginal environments,  gatherable food
resources are usually plentiful throughout the year.

Second, hunting is a prestige activity that yields a much-valued food.  A
successful hunter has much to gain in terms of social standing, improved
reproductive opportunities and
having the werewithal to build social and politcal alliances.  The
scarcity of this food resource, and its high price in terms of the time
and technology necessary to obtain accounts for its high value, and the
benefits that accrue to an individual who can supply it.

I agree that meat from large-game is a valuable, high-quality protein
addition to the diet.  However, if it is not available there are other
resources that can supply the same foodstuff.  The group can obtain their
protein needs through the consumption of nestling birds, songbirds, eggs,
lizards, mice, insects, rabbits, etc. etc. etc..  As long as the total
calorie intake is sufficient, a relatively small amount of dietary
protein will suffice to keep the females fertile and lactating, the
children and adolescents growing at optimal speed and the adults healing
and manufactuirng any polypeptides necessary for maintenance and upkeep.

References on the diets and food-getting activities of hunter-gatherer
groups are scattered
throughout the ethnographic literature, and much information on this
topic can be obtained through a search in the Human Relation Area Files.
I can also refer you to such workds as Richard Lee and Irven DeVore"s
Man the Hunter (Aldine, Chicago, 1968),  M. G. Bicchieri's Hunters and
Gatherers Today, (Holt, Reinhart and Winston, 1972) and Frances
Dahlberg's Woman the Gatherer (Yale University Press, 1981)

Lorraine Heidecker
Department of Anthropology
California State University Sacramento