Last night, a barefoot and gumbooted group of frog fans gathered at the Karkloof Conservation Centre for an evening of sploshing about in mud and finding frogs. “African Bullfrogs are my favourites” said John Robbins. “In Grade R a friend brought one to school and I have liked frogs ever since.” One of the first questions asked was what the difference between frogs and toads is. “They are all frogs” said Charlene Russell who was leading the excursion. She explained that the confusion had arisen long ago in Britain where only two frog genera occur naturally – Rana (frogs) and Bufo (toads). Toads are types of frogs.
Zoe Goble had been reading a book about frogs and asked about poisonous ones. All frogs secrete a toxic substance from glands on the back of their neck, but in most cases the concentration is small and they are not very poisonous. It is the brightly coloured ones found in the rainforests which are dangerous.
Everyone was interested to hear about the Platanas (African Clawed Toads) which were used to test pregnancy until the 1960s. Unfortunately, Platanas have a fungus on their skin which other South African frogs are immune to, but because they have been transported around the world, the fungus has spread to other frogs and is thought to have caused the decline of many populations.
We began by listening to recordings of frog calls so we’d be able to identify them more easily once in the wetland. Frogs are more often heard than seen. None of the frogs we heard were calling “Ribbet”, because very few do. Apparently, there is a species of frog which does make that sound in the wetlands around Hollywood, so because we always hear that call in movies, we now say frogs go “Ribbet”!
Margaret and Barry Neuborn admitted to listening to frog calls in the car, rather than music! “We hear lots of frogs at might in Mbona because a small stream runs next to our house,” said Margaret. “Often tiny frogs sit on the outside of the window and we can see their hearts beating. ” Charlie McGillivray lead the way around the vlei so we could hear the real frogs. We identified six by their calls: Bronze Caco, Painted Reed Frog, Tinker Reed Frog, Guttural Toad, Platana and Yellow Striped River Frog.
Much splashing about and shining of torches followed.
The first frog we caught was a Guttural Toad.
We also found a number of pretty little Painted Reed Frogs. Their markings are completely different in different areas of the coutry which causes confusion. They also fade in sunlight, probably as a defence against the sun. We popped what we caught into plastic bags to observe them for a while. As their skins are porous, they will absorb any substances we had on our hands and we didn’t want to harm them.
John held this one gently by it’s pelvis so we could all have a look before it leapt away. Zoe tried to photograph hers in the plastic bag. The children were definitely the best at finding and catching the frogs!
We also caught a Tinker Reedfrog and a Yellow Striped River frog.
Great fun was had by all. We headed back for coffee in frog themed cups which Twane Clarke had created especially for the occasion, and a braai at the Nick Steele picnic site.
A thoroughly interesting and enjoyable evening, celebrating wetlands and the special creatures which inhabit them. Thanks to Karkloof Conservancy for arranging it. see: http://www.wwf.org.za/what_we_do/species/sa_frogs/