Image:Aardvarks are elusive, making it difficult to estimate population size.
Photo credit: Photos: Gareth Whittington-Jones
Roelof Bezuidenhout speaks to Gareth Whittington-Jones of the Wildlife and Reserve Management Research Group at Rhodes University about his research on the aardvark in three nature reserves in the Eastern and Northern Cape, and its role in shaping the ecology of a region.
Even though aardvarks damage roads, dams and fences, and help predators such as the feared black-backed jackal to survive by providing them with burrows to rear their young, aardvarks should be regarded as important ecosystem engineers. “They create structures which may concentrate food resources and provide refuge for other species from predators, climatic extremes and fires,” says Gareth Whittington-Jones of the Wildlife and Reserve Management Research Group, Department of Zoology and Entomology at Rhodes University in Grahamstown.
His MSc research has led him to believe that the aardvark may be important in maintaining the biodiversity in arid and semi-arid ecosystems, which are characterised by extreme temperature fluctuations and sparse veld cover that make life difficult for wild animals.
“Burrowers such as the aardvark create three-dimensional underground structures that are utilised by other species as the soil’s insulating properties moderate the below-ground environment in both hot summers and cold winters,” Whittington-Jones says. Research conducted in Botswana shows that aardvark burrows are used by a wide variety of animals, from birds to reptiles as well as 17 species of mammals ranging in size from the pouched mouse to the leopard. But Whittington-Jones thinks a more intensive study will uncover an even greater selection of animals, as well as insects, that depend on the aardvark for refuge.“Arid plant communities have also been shown to be influenced by the activities of burrowing species,” he says. “Various rodents, for example, clear patches around the entrances to their burrows and in so doing open up spaces for annual plants to germinate and grow.”
Whittington-Jones’ research was conducted on three game reserves: Kwandwe Private Game Reserve (Eastern Cape), Mountain Zebra National Park (Eastern Cape) and Tswalu Desert Reserve (Northern Cape) and was motivated by the need for more knowledge on aardvark ecology.One of the interesting results of the study is that species richness and the number of individual rodents trapped was higher inside the burrows at Kwandwe, while the opposite trend was observed at Tswalu. “This could be because of the softer soil at Tswalu which enables smaller mammals to dig their own smaller burrows. These may be better insulated and give even greater protection from predators than the much larger burrows created by the aardvark,” says Whittington-Jones.
However, he found no significant difference in the available seed biomass inside the burrows and the surrounding areas outside. “All granivorous animals may benefit from the protection afforded by aardvark burrows when they are foraging,” Whittington-Jones says. Smallstock farmers who know that the feared black-backed jackal also uses aardvark burrows to rear its young often toy with the idea of making war on the anteater as well.But Whittington-Jones is quick to point out that there’s another side to the coin. “Aardvarks eat termites and ants which have the capacity to significantly reduce the standing biomass of grass,” he says. “Obviously if you’re a stock farmer, grass is important to feed your livestock and you should therefore be grateful that the aardvark can reduce termite and ant numbers, and so conserve forage for your flocks. It has already been shown in many areas that experience heavy grass losses due to ants and termites, that the aardvark and many other ant- and termite-eating birds and mammals such as the aardwolf have been heavily persecuted by people.
“In some districts aardvarks are killed for bush meat, curios, medicine and good luck charms. But people should remember that because of their slow reproductive rate (gestation period of about seven months only giving birth to single progeny) that they are vulnerable to local extinction,” Whittington-Jones says. “It really is a mystery why the IUCN Red Data Book lists them in the ‘least concern’ category. Aardvark are nocturnal and elusive and it’s very difficult, if not impossible, to accurately estimate population size – which has been put at about 10 000 individuals.”
E-mail Gareth Whittington-Jones at [email protected]. |fw