15 13
www.thevillagenews.co.za
29 April 2020
MY ENVIRONMENT
When is a frog a toad? By Anina Lee
A
ll toads are frogs, but not all frogs are toads. Let me explain. All frogs, including toads, belong to the order Anura – meaning ‘without a tail’. The order Anura contains many families, one of which is the Bufonidae, or toad family. So toads are a family of frogs. So what are the characteristics that distinguish toads from frogs? In plain language, when is a frog a toad? There are some obvious distinctions, but be aware that these are general characteristics and there are exceptions to every ‘rule’. The Bufonidae or ‘toads' have a thicker, drier skin than other frogs. A toad's skin is often covered with bumps and glands, which is probably why some people think you can get warts by touching them. While this is a myth, frogs and toads alike can secrete any number of toxins through their skins. Having a thick skin permits toads to live away from water longer than most frogs, so you're more likely to see toads on dry land. Because they need a different kind of camouflage to live the terrestrial life, toads are often brown in colour, which
PHOTO: inaturalist.org
is another way to distinguish them. Toads also prefer to walk while most frogs hop or leap. If you see an amphibian leaping into a pond or river, it’s a true frog, not a toad. Most frogs and toads are carnivorous, have species-specific mating calls and reproduce and develop in water. And most importantly, both frogs and toads are under intense extinction stress from human activities. Frogs are some of the most fragile, most environmentally vulnerable species on earth, which is why they are so good at telling us whether their natural environment is healthy or not. If their habitat is degraded, they won’t be found there. In essence, they can be regarded as ‘mining canaries' for the entire planet. It's the very sensitive skin that makes them more susceptible to environmental pollution. And it is cause for great concern that frogs are declining significantly in numbers and diversity. Their demise could signify major problems for the global ecosystem. Western Leopard Toads (WLT) One toad is of particular interest in the Overstrand. Most people know about the endangered Western Leopard Toad (Sclerophrys patherinus). These toads have captured the imagination of the public due to the efforts of volunteer groups in the Cape Peninsula and Stanford to save them from getting squashed by cars. These toads are particularly vulnerable during July and August when they return from their foraging grounds to their breeding
PHOTO: David Sykes
ponds to mate and breed. A week or so later they trek back to forage again. In the process they cross busy roads, or fall into steep-sided swimming pools, with deadly consequences. The tiny baby toadlets emerge from the breeding sites about 10 – 12 weeks later in spring to seek food. They, too, have to cross roads and other physical obstacles, often leading to a great loss of numbers. In the words of CapeNature: “This beautiful toad can reach an impressive size of 140 mm in body length and, like all toads, has a rough skin and a large parotid gland behind each eye. Its upper body has chocolate to reddish-brown patches on a bright yellow background, and there usually is a yellow stripe running down the middle of the back. The underside is granular and cream coloured, with a darker throat in males. The mating call of the males is a deep snoring sound repeated every few seconds, and in chorus sounds like a tractor or motorcycle engine.
ABOVE: Cape River Frogs (Amietia fuscigula).
PHOTO: Sheraine van Wyk
RIGHT: Raucous Toad (Sclerophrys rangeri).
LEFT: Western Leopard Toad (Sclerophrys patherinus).
“This species is endemic (restricted) to the coastal lowlands of the south-western Cape, with a distribution range that extends from the Cape Peninsula and Cape Flats to the Agulhas Plain. Sadly, its distribution is now very fragmented and these toads have not been recorded in the area from Pringle Bay to Hermanus in recent years.” According to Sheraine van Wyk, Whale Coast Conservation’s frog fancier, Western Leopard Toads can still be found on a few farms along the Klein River in the Stanford area and in ponds down the coast to Pearly Beach. Difference between a Western Leopard Toad (WLT) and a Raucous Toad A number of people in Hermanus have excitedly re-ported seeing what they believe to be a Western Leopard Toad in their gardens. But in reality, it is most probably a Raucous Toad (Sclerophrys rangeri). Urban expansion and human activities have destroyed the WLT habitat from Pringle Bay to Hermanus. The closest you will see them nowadays is in the Stanford area.
PHOTO: Sheraine van Wyk As mentioned above, the WLT is generally brighter and yellower in colour and the markings are a distinct chocolate brown. But there is another way to tell the difference. Look at the dark markings on top of the head/neck behind the eyes. In the WLT the dark marks are interrupted in the midline (not continuous) so they don’t form a solid band. In the Raucous Toad the dark patches are fused into a bar behind the eyes. Many people living in the Cape Whale Coast region are environmentally conscious and attempt to have eco-friendly gardens that will attract bees, chameleons, butterflies and other wildlife. If a frog of any kind
BOTTOM LEFT: Painted Reed Frog (Hyperolius marmoratus)
chooses to live in your garden it indicates the ultimate approval. Even if it is only a very raucous toad, you can be very proud indeed. A last word from the Table Mountain Fund: ”The sobering reality is that frogs were here before the human development that now threatens it. Conservation efforts aim to protect the Western Leopard Toad and recover the population to a point at which the species can thrive. Equally critical, though, is maintaining a healthy Western Cape biodiversity, with fit, functioning wetlands and pesticide-free gardens that complement our natural ecosystem. How do we know if we’re doing this? The toad census will tell us.”
