- An interesting article by David Johnson
 Mole-hills are a common sight almost everywhere, and are not always welcome in formal gardens and lawns. They are usually blamed on “moles”, but there are actually two completely different animals responsible.
Most mole-hills are the work of mole-rats. These are rodents, and not related to moles. Mole-rats are vegetarian, and have typical huge rodent front teeth (incisors) that grow continuously. They have a social organisation very different to other rodents, and it is much more like that of social insects such as ants or bees. The colony is ruled by a queen, and all the workers are female. The males loaf around, doing little. Every day the queen licks the workers; they may think this is affection, inspiring loyalty, but her saliva contains hormones that suppress the workers’ reproductive instincts. The workers then set off along their extensive tunnel system, burrowing further in search of tubers and bulbs. The tunnels may be half a metre down, and do not disturb the ground surface. Burrowing creates loose soil that occupies more space than compacted soil, hence the need to make vertical chimneys at intervals to dispose of the excess. Any food found is “reported” back to the central chamber so that all the workers can come and share bigger tubers. A portion is taken back to the queen. This shared information system works well when food is unevenly scattered in large units. When the queen dies her suppressive hormones die too, and a fierce contest develops among the workers before a new queen becomes dominant.
Golden moles are insectivores with many small pointed teeth. They eat earthworms and insect larvae. Golden moles are not really yellow, but have a golden sheen when seen in bright light. They are solitary and territorial, and males that meet accidentally usually fight to the death. Their burrows are so much shallower than those of mole-rats that they lift the turf above. Golden mole-hills are clearly linked by an irregular wiggle on the ground surface.
Despite the similarity in appearance golden moles are not closely related to the true moles of the northern continents, but are Afrotheres whose cousins include the hyrax, elephant and aardvark. Strangely enough most of the animals we think of as typically African — the carnivores and great antelope herds — are recent invaders from Asia; Africa’s original surviving inhabitants are now the minority.
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Our Activities Calendar for 2012 is finalised and we have added a new activity – Journaling in the Berg – Join Elsa & Gill in April to create your own natural history sketch book. Old favourites remain – painting workshops, birding, photography just to mention a few. And, let us not forget the Cavern Bowling – the Cavern Team is ready for November 2012 and we look forward to improving our scores next year!
