Six-month-old Jessie has just started her training to sniff out these frogs under the ground. The Giant Bullfrog is currently a protected species in Gauteng because its habitat is gradually shrinking due to urbanisation.
Jessie’s owner, Esté Matthew, says she came up with the idea and after a conversation with her supervisor, Professor Ché Weldon, they developed a programme in which Jessie could help with Matthew’s study in zoology. Jessie comes from two working parents on a sheep farm near Bloemfontein.
Because Matthew lives in Wag-‘n-Bietjie residence, Jessie is staying with a friend of Matthew’s. A research colleague of Weldon and geologist from Sweden, Peter Bergman, recently visited them to help with Jessie’s finer training. Bergman’s own dog, a German shepherd, was trained to help with mineral exploration.
Matthew said they started her training two weeks ago and are amazed at how quickly she has progressed. They initially started with biltong in a container and later made a tea mixture, which they gradually diluted until there was only 1% tea in the mixture. Jessie could still sniff it out. They then started with frog-skin smell, so that she would not be anxious when she encountered a live frog for the first time. Matthew said Jessie could already sniff out one to 100000th of the smell in a box under the ground.
“It is simply phenomenal and we have no idea how sensitive her sense of smell is.” Jessie was initially trained under laboratory conditions and later in a controlled intermediate stage (mesocosm) in the outdoors. The next step will be to take her into the field in areas where bullfrogs are known to occur. Weldon says the training is done in a scientific, reliable way and the same test is repeated up to 40 times to ensure a reliable result.
Weldon says the African Bullfrog hibernates underground for up to 11 months of the year and is above ground for only about a month (usually November/December) to breed and to lay its eggs, if it rained sufficiently. “This makes it extremely difficult to find the frogs during the rest of the year. The frogs must be detected before development starts, otherwise the development can be stopped and this will cost developers millions of rands.”
Weldon and his colleague, Professor Louis du Preez, performed such an investigation for Transnet near Heidelberg in Gauteng two years ago, where they spotted the bullfrogs and could make the right recommendations for the development in the area. “If we did not do the investigation in the breeding season, we would not have found the frogs.”
The purpose of Jessie’s training is to sniff out the bullfrogs in time, to help conserve the species and to explore the ecology around their habitat. Weldon says it will also help to determine a buffer area around the habitat, because there is no knowledge about the behaviour of the young metamorphs. Weldon says Jessie will later also be trained to sniff out frog diseases, to help them in the diagnostic phase.
Currently, frogs are caught and expensive and time-consuming molecular tests have to be done in laboratories to determine whether the frogs have certain skin infections. The fungi on the skin give off a distinctive smell, which Jessie’s sensitive nose can possibly pick up. He says Matthew is focusing on the bullfrog for her MSc, but in the next phase, in a PhD study, her focus will extend to help sniff out other endangered species, such as the Amatola Toad in the Hogsback area.
The frog “disappeared” for 12 years, before it was seen again approximately three years ago. “The species is not extinct, but is found in an extremely small area and we may be able to use Jessie to search for other individuals or populations. She will help us to research the distribution and conservation status of the Amatola Toad.”
Jessie, with her sparkling eyes and wagging tail, can still become a valuable tool for learning more about frogs, to protect the species better.
This supplement has been paid for by the North-West University Potchefstroom Campus. Contents and pictures were supplied and signed of by the NWU