We study reproductive allocation in a subset of the colonies at our study site.  We use those colonies shown above in blue.  Each year we water the colonies [see:  Cole, B.J. and D.C. Wiernasz. 2000. Size and reproduction in the western harvester ant, Pogonomyrmex occidentalis .  Insectes Sociaux.  47:249-255. for method and here for a picture]  Then we place a cone over the surface of the colony to collect all of the reproductives.  We measure the number of males and queens produced each year as well as the sizes of the males and the queens.  Since we know that body size influences the fitness of the reproductives this gives us a measure of the fitness of the colonies.  We have been measuring the reproductive success of these colonies since 1994.