A maze-lover's dream: Burrow architecture, natural history and habitat characteristics of Ansell's mole-rat (Fukomys anselli)

Abstract

a b s t r a c tThe Ansell's mole-rat (Fukomys anselli, Bathyergidae) is a small-sized social subterranean rodent whose distribution is confined to the Lusaka area in Zambia. It is an established model species for various laboratory studies, but until now the knowledge of its biology under natural conditions has been limited. Here, we provide the first comprehensive natural history and ecological data on a free living population from Miombo woodland. The Ansell's mole-rat lives in groups of up to 13 individuals (mean 9.7 ± 2.5; N = 9 complete, fully established family groups) with a single breeding pair per group. The family groups occupy very large and complex burrow systems consisting of 0.5-2.8 km of tunnels (mean = 1.2 ± 0.6 km, N = 15), which are densely branched and reticulated especially around nests. Burrow systems of neighbouring family groups were often interconnected by a freely passable tunnel, which has never before been documented in any African mole-rats. Mole-rat food density in the study area was relatively low (10.0 ± 8.4 m −2 ) but its biomass was large (457 ± 889 g m −2 ). This, together with a relatively workable soil (cone resistance = 529 ± 26 N cm −2 at the end of June, with 10% soil humidity), indicates moderate ecological conditions, which disagrees with the aridity food-distribution hypothesis (AFDH) considering small body size and sociality in bathyergids adaptations to harsh environments.

Variability of space-use patterns in a free living eusocial rodent, Ansell’s mole-rat indicates age-based rather than caste polyethism

“…22 for further details). Specifically, there was a freely passable tunnel connecting the burrow systems of P01 and P02 and another one between P05 and P10.…”

“…Consequently, laboratory-based findings obtained in captive mole-rat family groups should necessarily be viewed with caution unless they are supplemented and confronted with findings obtained from free-living animals. In the wild, eusocial mole-rats live permanently in large burrow systems sealed off from the surface and consisting of up to three km of branched and reticulated tunnels extending over an area which can exceed 1 ha202122. The burrow systems usually have long-lasting communal nests and axial tunnels providing access to areas where they branch into shallower foraging tunnels222324.…”

“…In the wild, eusocial mole-rats live permanently in large burrow systems sealed off from the surface and consisting of up to three km of branched and reticulated tunnels extending over an area which can exceed 1 ha202122. The burrow systems usually have long-lasting communal nests and axial tunnels providing access to areas where they branch into shallower foraging tunnels222324. In some mole-rat species, the burrow systems of neighbouring groups can be interconnected by open or partially blocked tunnels, thus forming vast communication networks2225.…”

“…The burrow systems usually have long-lasting communal nests and axial tunnels providing access to areas where they branch into shallower foraging tunnels222324. In some mole-rat species, the burrow systems of neighbouring groups can be interconnected by open or partially blocked tunnels, thus forming vast communication networks2225.…”

Temperature preferences of African mole-rats (family Bathyergidae)

“…Also, in open-fieldtests, subterranean rodents prefer corners and walls, and compared to laboratory mice they are less ready to enter the open field (own observation). The burrow systems of subterranean rodents are generally of similar architecture sometimes containing several nests per system, which might be located at different depths with slightly different ambient temperatures (Brett, 1991;Scharff et al, 2001;Lövy et al, 2012;Šklíba et al, 2012). While temperatures fluctuate daily and seasonally in shallow tunnels, more or less constant temperatures prevail at depths of 50 cm or deeper (reviewed in Burda et al, 2007).…”