Ed. Wallace et Nc. Bennett, THE COLONY STRUCTURE AND SOCIAL-ORGANIZATION OF THE GIANT ZAMBIAN MOLE-RAT, CRYPTOMYS MECHOWI, Journal of zoology, 244, 1998, pp. 51-61
Cryptomys mechowi is a social subterranean mole-rat which inhabits the
mesic regions of south-eastern and central Africa. Giant mole-rats li
ve in colonies of up to 11 animals in which reproduction is normally r
estricted to the largest male and female in the colony. In this prelim
inary study on a laboratory-reared colony, the non-reproductive member
s of the colony could not be placed into clearly defined, work-related
groups based on body mass. The colony showed a work frequency related
division of labour. Reproductive animals performed little work, 3-4%
of the total work. The non-reproductive caste was divided into two gro
ups based on the amount of burrow maintenance activity: those performi
ng between 7-11% of total work and those ranging from 15-22% of total
work. Male members of the colony tended to perform more work than the
females. The dominance hierarchy of the colony was found to be nearly
linear, with a value of 0.83 calculated from Landau's linearity index.
The reproductive animals were the most dominant in their respective g
ender. Dominance was not age-related. However, non-reproductive males
tended to be more dominant than non-reproductive females. Social organ
ization within the giant Zambian mole-rat is compared with other south
ern African Cryptomys species in the light of the eusociality continuu
m.