Abstract:
Ansell’s mole-rat, Fukomys anselli, is a cooperatively breeding bathyergid endemic to the
Lusaka Province of Zambia. During a 12-month field study involving the capture of 33 colonies
of mole-rats, the number of occupants, breeding females and sex ratio within colonies were
recorded. While thirty of these social groups contained a single breeding queen, three were
found to exhibit plural breeding among females, having two queens present simultaneously.
Mean±S.E.M. colony size was 8.7±2.2 (range 6–16,n=33). The occurrence of plural breeding
and small group size is consistent with the predictions of the aridity food distribution hypothesis
for social species inhabiting mesic habitats. The sex ratio of the population was skewed
towards females at 1.2:1. The mean mass of adult males was 63.0 ± 18.3 g (range 36.7–110.3,
n=87) while that for adult females was 52.9±11.8 g (range 35.1–77.8, n=86). Pregnant and
lactating females were found throughout the study period from February 2009 to February
2010, indicating an aseasonal pattern of breeding in this species. Autopsy of individuals
(n = 288) from the 33 colonies revealed a total of 19 pregnant females. Nine of these were in
the latter stages of pregnancy and mean litter size was determined as 2.7 pups (range 1–4).
Collectively, these new data reveal that Fukomys anselli share many similarities in life history
and reproductive traits with the phylogentically closely related giant Zambian mole-rat,
Fukomys mechowii.
