Cape Mole Rat - Behaviour

Behaviour

Like other mole rats, Cape mole rats rarely travel above ground, and spend most of their lives within excavated burrow systems. Their burrows typically range from 50 to 130 metres (160 to 430 ft) in length, with tunnels about 10 centimetres (3.9 in) wide. They are herbivorous, feeding on the bulbs, corms and tubers of plants such as Star-of-Bethlehem, Cape tulips, and wood-sorrels, among others. They obtain this food by digging foraging tunnels to reach plant roots; these tunnels are narrower than their main tunnels and may be as little as 0.5 to 2.5 centimetres (0.20 to 0.98 in) below the surface. Food may also be taken to deeper storage chambers to store up for hard times, or when a female is raising young. They have no need to drink, being able to obtain all the water they need from their diet.

In order to feed on bulbs, Cape mole rats hold the food item in their fore-paws, chew away the base, and then peel away the husk with their teeth, moving from the tip to the base, in the manner that humans peel bananas. They have an enlarged caecum, and, like rabbits, are coprophagic, passing food through their digestive tract twice.

In addition to storage chambers, the centre of the tunnel system includes a nest, and a separate latrine chamber. The tunnels are entirely closed off from the surface, although their presence may be evident from dome-shaped mounds of excavated material similar to mole hills. As a result, there is little circulation of air within the tunnels, which are therefore hypoxic and humid, but are protected from extremes of weather. The mole rats occasionally travel above ground to forage for surface vegetation, and to disperse to found new burrow systems.

Despite spending almost their entire lives underground, and having very poor eyesight, Cape mole rats exhibit distinct diurnal rhythms in time with the hours of daylight on the surface, and are primarily nocturnal. Unlike some other species of mole rat, they are solitary animals, and, except when a female is raising young, only one individual inhabits each burrow system. They are highly aggressive towards other members of their own species outside the breeding season. When encountering a rival, they adopt a rigid posture with the head thrown back and jaws open, chattering their teeth and occasionally making short leaps in the direction of their opponent. Because burrow systems can approach within 2 metres (6 ft 7 in) of each other, burrowing animals warn away rivals using sex-specific seismic signals.

Cape mole rats become alarmed if they sense a breach in their tunnel system, moving cautiously towards the break, and making characteristic 'pumping' motions with their hindquarters, of unknown significance. Predators that may enter the tunnel system to feed on Cape mole rats include mole snakes and Cape cobras. They are particularly vulnerable while travelling above ground, where they may also fall victim to jackals, mongooses, owls and grey herons.