KZN’S nocturnal treasure at risk
YOU don’t like bats. You think of them as disease-spreading creatures to be avoided at all costs. On the very mention of the word your mind spins into the dark blood-sucking world of Dracula.
You might not know it but Durban is one of the bat hot spots in the country. What’s more, KZN is home to 39 of the 57 species of bat found in South Africa and one bat – the longeared free-tailed bat ( Otomops martiensseni) – is only found in Durban.
A bat scientist who is trying to reposition this furry nocturnal flyer far higher in the acceptable and likeable range is Dr Corrie Schoeman, evolutionary ecologist at the School of Life Sciences, University of KwaZulu-Natal. He has devoted most of his working life to understanding this much-maligned creature and believes Durban is one of the best places to study bats.
But the numbers, he warns, are dwindling. White nose syndrome, for example has wiped out millions of cave-dwelling bats in the US, a fungus believed to be spread by human activity in the caves.
Closer to home, an ongoing study by one of his PhD students in the School of Life Sciences has earmarked Durban’s waste-water treatment works as potential killers of the smallest bat species in Durban, the Banana bat, because of heavy metal pollution.
“Many of these sites – there are 32 in Durban – have poor wastewater quality compliance,” explains Schoeman. “In the short term certain plants and animals may benefit from the nutrient rich ground water, while bats will feed off aquatic insects, but our studies tell us that the long-term effects may be devastating. They include physical abnormalities like metal deposits found in the liver and kidney, changes in the blood, enlarged liver and kidney and possible negative effects on male bat breeding organs (testes).
“It is not easy to change perceptions,” says Schoeman, a former legal graduate who decided to change course and opt for the realms of science and more specifically the “understudied” world of bats.
“If these creatures don’t survive, there are a whole lot of negative consequences,” he says. “In environmental terms they provide a valuable service and when bat populations are destroyed, the ecology suffers, crops are damaged and disease risks heighten.”
Schoeman says it is therefore important that we should encourage these unique flying mammals into our lives.
“They feed on harmful insects like mosquitoes and plant pests, they disperse seeds and pollinate plants.”
“Plus, plus, plus” he says. “They are actually charismatic, won’t get entangled in your hair – and definitely won’t be sucking any human blood.”
Why do we hate them so much?
“Mainly because they fly at night and look dark and ghostly in the sky,” says Schoeman. “The myths surrounding the vampire bat, for example, can be dated back to ancient Babylonia, millennia before the first reports in Europe about bloodfeeding bats, and messengers of the supernatural.
“The Dracula myth also hasn’t helped their cause one bit. True, there is a group known as Vampire bats that live in central and South America, but they feed on a wide variety of warm-blooded animals, mainly cattle, seldom humans.”
The real problem, he says, is that studying these nocturnal flying mammals is difficult.
“It’s not like bird spotting which is relatively easy in day- light,” says Schoeman. “You can’t ring them easily, so there is little information on how far they fly, or even the colonies.”
However, new technologies like heat-sensitive cameras and radar are helping. As are radio transmitters that are temporarily attached to the bat’s back to monitor its movements.
What scientists like Schoeman know is that bats come in a variety of shapes and colours, even yellow and white, they are extremely intelligent, some species live for more than 30 years, have been around for at least 65 million years, are curious and feel like silk.
It is these attributes, he says, that have attracted more and more students to the world of animal science with bats at the top of the research list.
“The whole Batman legacy certainly helps!”
“Bats can teach us so many things. They are nature’s Rolls Royce and deserve so much more research.”
Raising the academic bar for the ailing bat population is necessary, he says, to protect them from further destruction.
Schoeman, this year’s recipient of UKZN’s distinguished teacher award, says: “If bats are in your roof or swooping over your head when the sun goes down, don’t chase them away. They are your friends, not flying rats, and certainly not vermin.”
Old World fruit bats have relatively large eyes with good light-gathering capacity, and can see in colour.
Most echolocating bats have small eyes, and see only in black and white, but still use sight to navigate long distance and avoid large objects at night. The main reason people think bats are blind is that they hunt at night and they use a form of sonar to find their way and their prey. This is not unlike dolphins who use echolocation to hunt, especially in the murky depths.
There are several myths surrounding bats. Some people say they are loathsome. Bats belong to their own order Chi-