Tunnel Voles

Tunnel voles are small, mice-sized creatures descended from the burrowerkin. As their name suggests they are a largely subterranean species, preferring to spend their lives underground in their tunnel complexes. Tunnel voles will occasionally venture topside in order to procure grass for bedding or to forage, but do not stray far from the safety of their burrows.

A tunnel vole’s family burrow is made to a largely uniform design. The main shaft descends vertically in a loose corkscrew pattern, up to a metre in depth. The small diameter of the tunnels prevents hunterkin from entering, and the corkscrew pattern frustrates any attempts to dig the rodents out. At the bottom of the shaft is the bedchamber, a small room filled with bedding where mated pairs reside and raise their young. Opposite the bedchamber is the larder; another room where tunnel voles store food for leaner times. A tunnel vole’s diet consists largely of tubers and invertebrates, with seeds taken during topside foraging. Stored invertebrates are kept alive for freshness and have their limbs and other ambulatory structures bitten off in order to stop them escaping.

Towards the top part of the tunnels is another room, used as a latrine. Soiled bedding is also disposed of here. The separate latrine keeps the tunnels free from waste and helps disguise the scent of the living voles from the tunnel entrance. Once the latrine is at capacity it is simply walled up and a new one excavated. These rooms of waste provide excellent nutrition for the surrounding soil, and it’s actually possible to detect the location of these latrines from the surface due to the grass directly above them being richer and healthier than the rest.

Tunnel voles live in loose colonies, with each family having their own separate burrow. Over generations of digging these tunnels can sometimes break into one another, becoming linked up with a network of passageways. Voles are tolerant of wanderers moving through the main shaft, but the chambers are strictly out of bounds to non-family members, and any intruders caught will be viciously driven off.

A pair of tunnel voles will breed twice a year, rising to three times during abundant years. A litter consists of up to five pups, which are born blind and completely helpless. They soon mature and will be ready to leave the nest at two months of age. Upon leaving the family burrows youngsters will immediately scatter in all directions, either digging a new tunnel a distance away from the family burrow or jumping into a newly dug existing one. If fortunate enough to enter a new burrow containing a single member of the opposite sex they will become a mated pair. If the burrow already has a resident pair the individual will leave and try another burrow, or dig their own and wait for the opposite sex to come to them. To maximise the chance of finding an available partner youngsters will often leave the family burrows during the same time frame. Although this creates a bonanza for predators the sheer number of youngsters means at least some will likely escape and go on to raise the next generation.