Painted Reed Frog

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Painted Reed Frog

Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"


This time I have another froggy for you! This is a Painted Reed Frog, Hyperolius marmoratus taeniatus. If you are familiar with my column you'll know that until now all the scientific names I've given consisted of two elements, a genus name spelled with a capital letter and a species name all in lowercase. So why does this one have three names?


The reason is that I'm here dealing with a subspecies. This is a division lower than species rank. Many species have them. In some cases it is difficult to know if a certain group of animals represent a subspecies or a species. So, there are different kinds of giraffes living in different regions of Africa, with subtle differences in their appearance; in one view all of these are just subspecies of a single giraffe species, while in another view they deserve to be called full species. It is difficult to resolve the problem since 'species' is actually not a rigorously defined or definable scientific concept.


In the case of the Painted Reed Frog, over its wide distribution that stretches from southern South Africa up into Kenya, there are many, many different forms … but even though the forms can look strikingly different they are typically not clearly distinguished from each other. You won't get one form in one place and a clearly different form in the next; instead you'll find as you travel from one region to another that the frogs will change by subtle gradations from the one form to the other, and you can get intermediate forms almost anywhere. The one I illustrated, the taeniatus subspecies, is found from northern Natal to central Mozambique. The typical version has straight black and yellow stripes going from the nose to the rump; intermediate versions have broken stripes, blending into the northern form angolensis (broken yellow stripes on a brown ground) and the southern marmoratus (fine black spotting or marbling on a light cream ground). There are many, many other forms with speckles, spots, blotches, stripes and squiggles in a great many different colours. But all have the same basic shape, call and habits. All of them start out as dull brown juveniles and acquire their distinctive colours and patterns as adults. The adult forms all have red coloration on the insides of their limbs and on the webs between their toes. While they sit with the limbs tucked in under their bodies, this bright colour is not visible, but when they move or jump and expose these areas there is suddenly a flash of colour which immediately disappears when the frogs land again. This may startle and confuse a predator, giving the frog a chance to escape.


As its name indicates the Painted Reed Frog is usually to be found where there are reeds. Actually mine is sitting on a sedge! Reeds, sedges or tall grass on the edges of savannah pans will do. This little frog, measuring 2.5-3.5 cm (an inch to a bit more) can easily climb up reed and grass stalks with its clingy fingers and toes. The stripey pattern actually helps break up its outline where it perches, usually lengthwise, on a stalk. Since the pans where they live dry up during the dry winter – the reeds, sedges and grasses growing on their edges typically also turning dry and brown – these frogs retreat to shelter to prevent themselves from drying out. Their winter hideouts can be deep down in clumps of leaves, under logs or stones, or even in people's homes! Being tiny and slender they can creep into small crevices; they've been found hiding behind cupboards and pictures on walls, and even in toilet cisterns.


When the rains come, the frogs come out. During the day they'll perch on reeds like this, often basking in the sun. Sometimes they'll climb into trees around the pans. At dusk they come down to the edge of the water and start to call. The calling can go on until after midnight. The males lay claim to fixed positions, sorting themselves out by listening to each other's calling. If one male approaches another too closely, the one defending its position will change its call to a harsh screech. If the intruder persists the two males will fight, the challenger trying to wrestle or kick the other from his perch. Once a male has established his position he will return to it on following nights. But each male will only call for a few consecutive nights, then take a break for ten days or so before returning and calling again. The call is a piercing, high-pitched peep, repeated at intervals of a second or so. On a savannah summer night close to a large body of water a chorus of hundreds of these little frogs can be heard.


Females heavy with eggs will come to hear the songs of the males, make her pick, and the pair will go into amplexus, the male clasping the female with his 'arms' under her armpits, in preparation for fertilizing her eggs. These she lays in clumps of about 20 on submerged leaves, reed stems or stones, or amidst the roots of aquatic plants. She can lay over 600 eggs in total. The tadpoles hatch out in five days and transform into tiny frogs in six to eight weeks.


These frogs still occur in large numbers in suitable habitat, and much of their range falls in protected places like the Kruger National Park. They can therefore at present be considered to be fairly safe.

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