I found a neat bit of information about a subsistence culture similar to the drykas. It pertains to their food.
It is impossible to define “abundance” of resources absolutely. However, one index of relative abundance is whether or not a population exhausts all the food available from a given area. By this criterion, the habitat of the Dobe-area Bushmen is abundant in naturally occurring foods. By far the most important food is the mongongo (mangetti) nut ( Ricinodendron rautanenii Schinz). Although tens of thousands of pounds of these nuts are harvested and eaten each year, thousands more rot on the ground each year for want of picking.
The mongongo nut, because of its abundance and reliability, alone accounts for 50 percent of the vegetable diet by weight. In this respect it resembles a cultivated staple crop such as maize or rice. Nutritionally it is even more remarkable, for it contains five times the calories and ten times the protein per cooked unit of the cereal crops. The average daily per capita consumption of 300 nuts yields about 1,260 calories and 56 grams of protein. This modest portion, weighing only about 7.5 ounces, contains the caloric equivalent of 2.5 pounds of cooked rice and the protein equivalent of 14 ounces of lean beef
Do the Drykas have an equivalent, or can we discuss and or create an option that would provide similarly?
Edit: I don't mean to ask for a miracle food that will solve the troubles of the Drykas, but rather a food that makes up the bulk of the Drykas diet. In the sea of grass this food is abundant and if nothing is brought back by hunters, you still have something to fill your stomach. Perhaps something as simple as sunflowers, which are abundant, filling, and have a multitude of uses from coffee, to stirfry.