Written by Fayruz Prins
When we think of frogs, what comes to mind? Their slimy skin, sudden leaps, or noisy croaks? While these are defining features, frogs are far more fascinating than what meets the eye.
Belonging to the Amphibia class, frogs are remarkable creatures capable of thriving both on land and in water. Interestingly, they are believed to be the first cold-blooded animals to have appeared on land! They consist of over 6,000 species worldwide, with Brazil accounting for 1 022 of the species in its lush tropical rainforests.
On World Frog Day, we honour these incredible creatures while raising awareness about the urgent need for their conservation. Nearly one-third of the world’s amphibians are threatened, with 200 species already extinct and hundreds more teetering on the brink of extinction due to habitat degradation, pollution, and climate change.
One of the species on the brink of extinction is a resident at Kenilworth Racecourse Conservation Area (KRCA), one of the biodiversity hotspots managed by Nature Connect. The area is nestled within the oldest racetrack in South Africa, established in 1881. For the last 143 years, it has protected 52 hectares of one of the most near-pristine critically endangered Cape Flats Sand Fynbos specimens. Unfortunately, such protection amid urbanisation always has its challenges and are susceptible to pesticides, pollution, garden escapees, water abstraction and governance issues. It is also home to 16 seasonal wetlands that transform the area during winter, and then dry up during summer. These wetlands are a sanctuary for frogs and other organisms inhibiting and utilising the abundance of food and shelter opportunities.
KRCA is also the perfect low altitude habitat to support a population of micro frogs (Microbatrachella capensis). The wetlands’ submerged vegetation and shallow, dark, acidic waters make a perfect breeding ground for micro frogs. There are only five known subpopulations of these frogs, with KRCA being the only site to host approximately 200 individuals on the Cape Flats. Three populations occur in the Overstrand of the Western Cape, between Betty’s Bay and Agulhas. In total, micro frogs only occupy an area of approximately 10km² in-situ. Their last known localities are of utmost significance for their survival. However, through successful conservation efforts and annual surveys, the KRCA population has shown to be stable with natural dispersal across the site to wetlands where new calls have been heard.
What do micro frogs look like?
As the name implies, they are tiny frogs barely the size of an adult thumbnail, at around 18 mm they are the smallest frogs in South Africa. We have observed seven different colour variations from copper brown to bright green and some exhibiting dark mottling. They have rounded snouts, smooth skin with a pale band of colour along each flank, adorned with a dark bar between their eyes and a thin longitudinal line running down their spine. Their toes are partially webbed, with the longest toe free of webbing. A good diagnostic to differentiate between micro frogs and flat caco’s (Cacosternum platys) are that the latter lacks the webbing between their toes.
Where do they live?
They inhabit sandy flats and coastal wetlands of the fynbos biome with the KRCA population being the most inland location. They prefer dark stained acidic water with a pH of 4.0-7.0. They prefer to take cover in emergent aquatic vegetation, and have observed companionship with Isolepis rubicundus, a sedge growing in abundance in the wetlands at KRCA. The other few known localities in the Overstrand are Groot Hagelkraal Private Nature Reserve, Kleinmond Coastal and Mountain Nature Reserve, Greater Betty’s Bay Nature Reserve, and recently discovered in Nuwejaars Wetlands Special Management Area.
A year in the life of a micro frog
Breeding starts as early as May and ends in October but peaks between July to August. This coincides with their breeding habits at KRCA, generally occurring towards the end of August. Though these frogs are tiny, the males are highly vocal with many calling from emergent vegetation in a chorus as competition for a mate increases.
The larval stage of the eggs and tadpole metamorphosis may take a while due to various environmental factors. Newly developed froglets start appearing in early December and once seasonal wetlands start drying up, they go into a state of aestivation. This means that the frogs bury themselves beneath the vegetation and the soil and begin to slow down their activity and metabolism to survive the dry season. Once the first winter rainfall appears they emerge from the soil and continue the frog life cycle.
What’s all the hype?
What makes this tiny frog so important you might ask? Well, out of 8 billion people, what makes this little guy so important? As tertiary consumers, micro frogs form part of our earth’s intricate food web serving both as prey and predator in the food chain. Without them and other amphibians we would be living in swarms of mosquitos, flies, grasshoppers and other insects. They are also a staple food source for many animals such as small mammals, birds, and reptiles. For example, the Rhombic night adder (Causus rhombeatus) feeds almost exclusively on frogs and toads. With frogs going extinct at an alarming rate, a vital food source and natural form of pest control is disappearing, the result of this could have devastating effects on the local ecosystem. Insect populations could skyrocket and threaten humans, livestock and plants. Amphibians serve an irreplaceable role in the environment.
A sad reality
Micro frogs are facing harsh threats that impact their population size and range. Their highly sensitive nature has resulted in unsuitable habitat conditions and degradation and loss of their historical extent because of urban expansion, agriculture, invasive alien plant species and water pollution which has resulted in their severe conservation status of critically endangered.
What can you do to help?
Though the existence of micro frogs depends on the success of conserving them in these last few localities, there is still hope not only for this species but for all amphibians around the world. Let’s adopt a pro-environmental attitude and make small changes to reduce our impact on their habitats. These sensitive beings breathe through their skin making it easier to absorb toxic pollutants. Through conservation efforts and public awareness, we can safeguard the Micro Frog and its habitat. By advocating for wetland protection, reducing pesticide use, and promoting frog-friendly environments, we can make a difference.
On this World Frog Day, unite with Nature Connect to protect these tiny yet indispensable creatures. Share this article, raise awareness, and act to ensure a future where Micro Frogs and all amphibians thrive.
