OUR COASTAL TREASURE

The sandy soils of the St Francis area were formed over millions of years as the sea level rose and fell across the Agulhas bank, a southerly extension of the African continent. The paleo-Agulhas plain was grassy, fertile and well-watered, but it was alternately exposed and submerged as the sea level changed with successive ice ages.

Today, our southern coastal sandy areas are the only remnants of this vast Agulhas plain that once teemed with life. These sandy areas are now fragmented and separated from one another, meaning that the frogs that were once widespread on the Agulhas plain are now separated into isolated little pockets. This is one of the reasons that the frogs of the St Francis area are special.  

There are 15 species of frogs that potentially occur here, which may sound like a lot but is really only around half of the species that are found in the Eastern Cape.

Arum Lily Frog

Photo credit: Luke Kemp

(http://thebdi.org/2021/10/30/arum-lily-frog-hyperolius-horstockii/)

Raucous Toad 

Photo credit: Jon Richfield
 (https://commons.wikimedia.org/wiki/File:Amietophrynus_rangeri_Raucous_toad_Probable_mature_female_IMG_3710.JPG)

1) About Frogs in General

Frogs are amphibians, a class of vertebrates (animals with backbones) that also includes salamanders and caecilians (legless, wormlike amphibians). The name “amphibian” refers to the fact that these animals are amphibious – can live on land and in the water. Their life-cycle usually includes an aquatic larval phase (i.e., tadpole) before metamorphosis occurs to produce adults that are largely terrestrial.  

Frog development from egg to adult

Photo credit: Tim Hunt (https://www.naturepl.com/blog/2019/03/12/clip-of-the-week-timelapse-of-common-frog-tadpoles/)

Amphibians colonized land from water more than 360 million years ago and today occupy all kinds of habitats, from wet rain forests to dry deserts. In order to do this, they had to adapt in many different and fascinating ways. Amphibians live a double life, one on land and one in water, and need specialized adaptations to both these environments. They are thus an evolutionary link between water-living and land-living creatures.

Frogs occur all over the world and, even though some people find them slimy, ugly and terrifying, they are actually a fascinating group of animals that are evolutionarily distinct and extremely important environmentally. If something is wrong with the frogs in an environment, chances are there will also be something wrong with the habitat in which they are found. They are not slimy, just wet, and their nightly (and sometimes daily) melodies are the very essence of nature.

For many years, scientists were puzzled by how amphibians reproduce. It was only later that they realised tadpoles aren’t fish  but are indeed the larvae of frogs.

Each frog species has its own unique call and position from which it calls. The call is thus an easy way of identifying the different species of frogs we get, without actually having to catch them. Be sure to listen to some typical frog calls recorded by the Endangered Wildlife Trust (https://www.youtube.com/watch?v=J1Sc78-TOFs).

No South African frog is dangerous to humans, although the poison secreted by their skin can be dangerous to small dogs. Unfortunately, frogs are threatened by a number of factors, with human activities causing the most damage. Humans destroy frog habitats, build dams, divert rivers, poison water sources, introduce pollution, and even drive over frogs while they are migrating across roads. The result of this is that frog populations have decreased in many places, and certain species are becoming rare and endangered.

2) Frogs of the St Francis Area

The sand dune system that occurs around St Francis forms part of the Agulhas shelf. However, it is always moving and changing. Over the past several million years it has experienced cycles of contraction and expansion well beyond the current coastline we know today. There are gaps between the remaining fragments of this Agulhas shelf system, meaning that populations of plants and animals found in these remnants are separated from each other. Thus, some amphibian species associated with the coastal sands have isolated populations on the Cape St Francis peninsula, which is separated from more extensive remnant Agulhas plain habitat to the west.  

This means that some of these isolated and poorly studied Eastern Cape populations may represent distinct species. There is also a possibility of finding species here that are currently only known to occur west of Mossel Bay. 

A big problem is that the remaining Agulhas shelf system is heavily impacted by the development of residential properties and tourism. Since the needs of frogs are seldom considered when planning new developments or tourist facilities, or even when implementing conservation measures, the result is that frog populations in this area become increasingly threatened. In addition, our local endemic (found only here) and patchily distributed frog fauna is seldom surveyed, meaning that we often do not know the status of the local populations.

Distribution of remaining dune fields around the St Francis area (light blue and purple).

From: Roberts, Cawthra and Musekiwa, 2013. (https://www.researchgate.net/publication/274972607_Dynamics_of_late_Cenozoic_aeolian_deposition_along_the_South_African_coast_a_record_of_evolving_climate_and_ecosystems/citation/download)

No frog species of special concern occur in the greater St Francis area, although it is an area where frogs that are out of place are occasionally recorded. One such odd record is of a Cape Sand Toad (Vandijkophrynus angusticeps). This species extends from the west coast around Vanrhynsdorp, south to Cape Town and east across the Agulhas plain to Mossel Bay. It has been recorded (a number of years ago) from only two locations east of Mossel Bay, one of which is near Oyster Bay. Another species is the Arum Lily Frog (Hyperolius horstockii), which is also mostly restricted to the Western Cape, with an old record from Humansdorp in 1965. A population of this species was recently discovered near Cape St Francis. (See pictures of both the Cape Sand Toad and the Arum Lily Frog under the respective species accounts.) 

The information on the following list of 15 frog species is based largely on data collected during the South African Frog Atlas project. Please see the list of references at the end of the article for further information.

A) Bufonidae

Family containing the true toads; distributed widely around the world, except in Australia and Antarctica. About 18 species in South Africa. All bufonids are toothless and warty in appearance. They also all have a pair of parotoid glands behind their heads, which contain an alkaloid poison that is excreted when the toads are stressed.

1. Eastern Leopard Toad (Sclerophrys pardalis)
2. Raucous Toad (Sclerophrys capensis)
3. Cape Sand Toad (Vandijkophrynus angusticeps)

Click here to find out about common toads in the St Francis area

B) Hyperoliidae

African reed frogs; brightly coloured frogs found in sub-Saharan Africa, the Seychelles and Madagascar. There are 16 species of reed frogs in South Africa. Most have smooth, brightly coloured and strikingly patterned skin that almost looks enamelled. They are small, usually between 3 and 8 cm in length, and often live in reeds or trees close to water bodies. The frogs in this family have sticky toe pads and extra cartilage between the last two bones of each toe, which makes their toes more flexible.

4. Arum Lily Frog (Hyperolius horstockii)
5. Painted Reed Frog (Hyperolius marmoratus verrucosus)
6. Rattling Frog (Semnodactylus wealii)

C) Brevicipitidae 

Rain frogs. Small, round frogs, mostly only measuring a few centimetres in length. Endemic to sub-Saharan Africa, from Ethiopia south to Angola and South Africa. Most species are terrestrial and fossorial (live in burrows). They are found in forest and desert habitats and may inflate their bodies into puffed-up balls when disturbed. They show direct development, meaning that they bypass the tadpole stage and baby frogs hatch straight from the eggs. There are 14 species found in South Africa.

7. Penther’s Rain Frog (Breviceps pentheri)

D) Pipidae

These are primitive, tongueless frogs found in South America and sub-Saharan Africa. In South Africa we have 3 species of clawed frogs, all of the genus Xenopus. Pipid frogs are highly aquatic and are adapted marvellously for life underwater. Their feet are completely webbed for swimming, their bodies are flattened and they have highly modified ears for hearing calls under the water. They lack a tongue or vocal cords, instead making noises using bony rods in the larynx.

8. Common Platanna (Xenopus laevis)

E) Pyxicephalidae

This is a diverse family that includes giant bullfrogs and smaller sand frogs, river frogs, moss frogs and dainty frogs.  They are endemic to sub-Saharan Africa and 48 different species are found in South Africa. They occur in a number of different habitats and may live on the ground, in trees or even in burrows.

 9. Boettger’s Caco (Cacosternum boettgeri)
10. Bronze Caco (Cacosternum nanum)
11. Cape River Frog (Ametia fuscigula)
12. Delalande’s River Frog (Ametia delalandii)
13. Striped Stream Frog (Strongylopus fasciatus)
14. Clicking Stream Frog (Strongylopus grayii)
15. Cape Sand Frog (Tomopterna delalandii)

SPECIES ACCOUNTS

A) BUFONIDAE – True Toads

1. Eastern Leopard Toad (Sclerophrys pardalis), Oostelike Luiperdskurwepadd

The species is almost endemic to the Eastern Cape Province, with only a few records in the Western Cape and KwaZulu-Natal. It occurs most commonly in the coastal regions between Gqeberha (Port Elizabeth) and East London, but has also been recorded inland from Makhanda (Grahamstown), Kei Road, Stutterheim, the Katberg area and from the Amatola Mountains.

Within their range, Eastern Leopard Toads inhabit grassy or open bushveld areas, parks and gardens in the thicket, grassland and savanna biomes, with some also found in coastal fynbos habitats.

They reach a large size, with adults being over 145 mm in length and weighing more than 400 g. They breed in early spring in deeper water bodies, where they lay thousands of eggs (10 000–25 000) in double jelly strings. The tadpoles, which are small and black, metamorphose (become full frogs) all at the same time and countless small toadlets migrate away from the water-bodies for the more terrestrial, adult phase of their lives.

These toads are classified as having stable populations at the moment, but are still threatened by habitat fragmentation, agricultural expansion and poisoning. During the breeding season, countless hundreds are run over on roads as they move away from the breeding wetlands. Eastern Leopard Toads are a sister species to the endangered Western Leopard Toad (Sclerophrys pantherina) that is found in the Western Cape.  

2. Raucous Toad (Sclerophrys capensis), Lawaaiskurwepadda

Raucous Toad 

Photo credit: JonRichfield  (https://commons.wikimedia.org/w/index.php?curid=17809802)

Raucous Toads make a loud, duck-like call that gives them their common name. They are endemic to southern Africa and found in all the provinces of South Africa. They are fairly aquatic as toads go, preferring to inhabit ponds, dams and streams, and seeking running water by choice. Although fairly shy, these toads will visit houses and gardens where insect prey are attracted to lights, and may even become established in sheltered spots such as behind flower pots, if not disturbed. 

Raucous Toads inhabit fynbos and grassland biomes in the St Francis area and are also very much at home in the artificial grasslands of agricultural areas. They frequently breed at sites around farm dams, large ponds and pools along slow-flowing streams. Males at these breeding sites will usually call from exposed sites on floating vegetation, in shallow water near banks, or among reed beds. Females lay thousands of eggs in spiralling strings that often become entangled in aquatic vegetation. 

They sometimes feed on small vertebrates such as lizards, but mostly catch insects as prey. This large toad is similar to the Eastern Leopard Toad, although it is smaller (120 mm in length). It is also more warty in appearance and has dark patches on the head that meet in a brown chevron between the eyes. 

Like most typical toads, they have a pair of large parotoid glands behind the eyes. If threatened or injured they will exude whitish drops of toxin from these glands, which is poisonous to domestic dogs if they ingest it.

3. Cape Sand Toad (Vandijkophrynus angusticeps), Sandskurwepadda

Cape Sand Toads are endemic to the fynbos biome, within which they are widespread, extending from near Humansdorp in the east, and along the coastal flats and Cape Fold Mountains, to Nieuwoudtville in the west. They prefer sandy flat habitat, which is not very common east of Mossel Bay. Thus, the few records from the Eastern Cape probably represent a population separated by the presence of the Garden Route. The sandy areas of the St Francis area, such as the Sand River, are a good place to go looking for this species of toad.

It is smaller than the previous two species of toads and produces fewer eggs (2 000–3 000). It is easily distinguished from other toad species in the area by its more prominent warts, the flash of yellow on its limbs and its smaller size.

It breeds in winter, after heavy rains have filled temporary depressions (holes) in the sandy soil. When these conditions are met, the toads emerge from their refuge places and move towards breeding sites. Their mating calls are weak and intermittent, unlike those of the Raucous or Eastern Leopard Toads.

The presence of this species in the St Francis area is a range extension and the most eastern record for them. Further molecular investigations may indicate that the St Francis population is actually a new species. The small area of occupancy in the sand dunes and the fact that this habitat is under threat may unfortunately give this frog critically endangered status in the St Francis area.

B) HYPEROLIIDAE – Reed Frogs

4. Arum Lily Frog (Hyperolius horstockii), Varkleliepadda

Photo credit: Abu Shawka

(https://commons.wikimedia.org/wiki/File:Hyperolius_horstockii_ArumLilyFrog_Cape_Town_5.JPG and 6)

This small frog cannot be confused with any other species. It is a pale beige colour and has a characteristic pale stripe, bordered below by a dark brown stripe, down each side of the body, from the nostril, past the eye and along the flank. Its orange feet are also diagnostic.

It is endemic to a narrow strip along the southern coast of South Africa, and is associated with coastal vegetation types in the fynbos biome. As its common name implies, it is often associated with arum lilies, Zantedeschia aethiopica, and will take shelter within these flowers during the day. However, this is not necessarily its only, or even its preferred habitat.

Previously the eastern limit of this frog’s distribution was thought to be at the Tsitsikamma National Park, but a specimen in the Port Elizabeth Museum was collected from Humansdorp in 1965. More recently, a population near Cape St Francis was discovered and so this marks the most easterly extent of this species’ occurrence. Since the population in our area is separated by quite a long distance from other populations, it may be that, over time, the St Francis population will evolve into a separate species. Molecular analysis of DNA will be able to find out whether speciation does indeed take place.

Although Arum Lily Frogs occur mostly in winter-rainfall regions, breeding takes place during spring and summer. Males usually call from elevated positions above water, generally on sedges, reeds, shrubs and grasses, but may also call from water-lily pads at water level.

Clutches of 10–30 eggs are attached to the roots and stems of plants below water level. Eggs have a diameter of 2 mm, within 4 mm jelly capsules, and are a whitish-cream colour with a brown hemisphere.

The species is known to feed on a variety of small, flying insects, and to be preyed upon by predators such as whiskered terns Chlidonias hybridus, water mongooses Atilax paludinosus, and other frogs.

5. Painted Reed Frog (Hyperolius marmoratus verrucosus), Geverfde Rietpadda

Painted Reed Frog (Hyperolius marmoratus verrucosus)

Photo credit: Tyrone Ping (https://www.tyroneping.co.za/amphibians-of-southern-africa/hyperolius-marmoratus-verrucosus/)

The Painted Reed Frog (Hyperolius marmoratus) is widely distributed throughout sub-Saharan Africa but there are many different subspecies, usually identified by their patterning and colouration. In South Africa, there are three recognised subspecies, and in the St Francis area we have one of those – H. m. verrucosus. This particular subspecies is brown with yellow spots and bright red legs and thighs. During the day these frogs can change their colour to pale white, which means they absorb less heat and keep cool.

The species is recorded from the south coast of KwaZulu-Natal, southward along the Eastern Cape coast to Tsitsikamma. It inhabits a wide range of natural habitats, including forests, savannas, shrublands, grasslands, rivers, swamps and freshwater lakes. It coexists well with humans, and is also found in pastureland, rural gardens, and urban areas.

Painted Reed Frogs have a loud, distinctive call and form large choruses that are active for an extended period during the breeding season. The call is high pitched and often repeated, filling the night with a cacophony of sound. When rain forms a marshy puddle at the edge of St Francis Drive, below Sea Vista, the Painted Reed Frogs can be heard calling there incessantly.

They utilise a wide variety of breeding sites, ranging from temporary ponds, pans and vleis, to permanent bodies of water such as dams, marshes, reedbeds, sluggish rivers and streams. Breeding takes place between October and February, when males call from high perches, such as trees, bushes and reeds near the water. Females choose a mate and lay their eggs in flattened clumps attached to submerged leaves, stalks or stones. They lay 150–650 eggs at a time.

Painted Reed Frogs are widespread and common in the St Francis area. They feed on different types of insects and are, in turn, preyed upon by other animals, such as snakes, birds and other frogs.

6. Rattling Frog (Semnodactylus wealii), Langtoonvleipadda

Rattling Frog 

Photo credit: A Sharp & P Coetzer

(http://thebdi.org/2021/11/18/rattling-frog-semnodactylus-wealii/)

The species name of this frog, wealii, honours James Philip Mansel Weale, an English naturalist who farmed in Bedford, Eastern Cape. He collected animal and plant specimens, including Rattling Frogs, and sent them to the Natural History Museum in London, England. Also known as Weal’s Running Frog, this amphibian is endemic to southern Africa where it is distributed along the southern coastal regions and northwards through Gauteng, northwestern KwaZulu-Natal, central Mpumalanga and western Swaziland.

These are beautiful frogs, with yellow-beige colouring over which bands, spots and blotches of chocolate brown are distributed. In particular, the three dark, divided stripes with pale centres on the back are characteristic. The hands and feet are yellow to orange in colour and the frogs are unusual in that they prefer to walk rather than jump.

Rattling Frogs reach a length of 44 mm from snout to vent and prefer to inhabit grasslands, although they are also found in fynbos habitats as well. They are tolerant of human activities and readily inhabit pastures, clearings in forested areas and grassy corridors between plantations of exotic trees. They occur at altitudes ranging from near sea level to 1700 m.

During the non-breeding season, this frog is terrestrial, hibernating in holes made by other animals, under logs or rocks, or within the roots of Restionaceae reeds (commonly known as thatching grass). When breeding season starts in spring, males call from a patch of grass and may even climb up reeds in order to broadcast better. They are very agile and can climb from one grass stem to the next with the greatest of ease.

They breed in any sort of pond (permanent or temporary, natural or artificial) that has emergent vegetation, as well as in marshes or dams that are in open grassland or in grassy fynbos habitat. There, the clutches of eggs are fertilized and attached to vegetation or other objects underwater. Each clutch contains 100–500 eggs.

Rattling Frogs can fake death when captured. They lie on their backs, curl their legs into the body and go all stiff for a few minutes. However, if they are released, they suddenly recover, turn over and quickly walk away. The skin contains small amounts of toxic substances that can cause severe physiological reactions in predators, if they dare to take a bite.

C) BREVICIPITIDAE – Rain Frogs

7. Penther’s Rain Frog (Breviceps pentheri), Penther se Reënpadda

Photo credit: LEFT – Werner Conradie; RIGHT – Bernard Dupont

(Bushveld Rain Frog (Breviceps adspersus) (12054760253).jpg)

This unusual little frog has been recorded in the Eastern Cape between Joubertina in the west, and East London in the east, where it prefers sandy to sandy-loam soils in semi-arid grasslands of the coastal region. There is a recognized breeding population in Makhanda (Grahamstown), where the loose soil of well-turned gardens provides an ideal breeding habitat. This is an uncommon species of frog in the St Francis area.

They are small, round-bodied frogs with a flattened face and short limbs. Females measure between 40 and 50 mm, but males are only half that length. They burrow backwards into the ground, using their hind limbs, and spend most of the time underground, only emerging after rains have fallen. They walk or run, rather than hopping like most other frogs.  

During breeding, the male is too small to hang onto the female as other frogs do, so he glues himself to the female’s back with a sticky substance. The female piggybacks the male around like this until she finds a suitable breeding place, usually a hollow or hole in the ground that is full of rainwater. She lays her eggs there, and the male fertilizes them. In a short time, fully developed froglets emerge from the eggs – they have no tadpole stage. They don’t need ponds or permanent water bodies in order to reproduce.

D) PIPIDAE – Clawed frogs

8. Common Platanna (Xenopus laevis), African Clawed Frog, Gewone Platanna

Photo credit: Brian Gratwicke

(Flickr: Xenopus laevis, CC BY 2.0, https://commons.wikimedia.org/ w/index.php?curid=23752908)

The Common Platanna is widespread in southern Africa where it inhabits any permanent bodies of water, including dams, rivers, pools and lakes. It is a fully aquatic species, spending all its time submerged in the water, except on rare occasions when it needs to move to other water bodies or when its own pond dries up. It is beautifully adapted to life under water; it has fully webbed feet, a flattened body and eyes on the top of its head. It also has claws on the three inner toes of each hind foot, which it may use for clawing its food to shreds before swallowing it.

This species of frog is highly invasive, meaning that it settles very easily into new areas and even new habitats, as long as it can find a water body in which to live. Experts think that it didn’t used to be so widely distributed, but has been introduced by fishermen, who commonly use the frogs as live bait. It is also a common aquarium species because it is easy to keep.

Whatever the cause, Common Platannas can be found in every biome in southern Africa, inhabiting all sorts of water bodies, from ice-covered lakes to desert oases. It has taken well to man-made water bodies such as farm dams, ponds, sewage purification works and fish farms – and it especially loves stagnant and still waters. It belongs to a family of frogs that has no tongue or vocal cords, but platannas still make a croaking noise using bony rods present in the larynx.   

Common Platannas enjoy a variety of foods, from small zooplankton and invertebrate larvae to insects, fish and the tadpoles of other frogs. They even eat adult frogs in some instances! Platannas are not above feeding on carrion, such as dead fish, and can easily be caught using a net and some meat or liver as bait. However, they produce copious amounts of slime and are very slippery to catch hold of. They are common in the permanent dams around St Francis, including those on the St Francis Links and on any farms in the area.

Since they breed easily in captivity, platannas have been used as laboratory animals all over the world. The development of their embryos has been studied, as well as their metamorphosis, their immune systems, hormones and genomes. They are used for biochemical research, to test the effects of potential new medicines. Interestingly they were also used to develop the first commercial pregnancy test for women during the 1930s to 1940s. The doctor would inject a woman’s urine into a female platanna and if the frog laid eggs the next day, the woman was definitely pregnant.

Because they are so widespread, Common Platannas are in no danger of becoming extinct. Instead, they are often found to invade the habitats of other frog species and proceed to eat their tadpoles, which can pose a threat to the populations of these other species. However, Common Platanna tadpoles and adults are also eaten by other animals, such as birds, snakes and mammals. 

E) PYXICEPHALIDAE

9. Boettger’s Caco (Cacosternum boettgeri), Boettger’s Dainty Frog, Gewone Blikslanertjie

This is a small frog, measuring no more than 23 mm, but it has a big call. Its Afrikaans name, “Blikslanertjie”, tells it all, literally meaning “hitting a tin can”. Their rapid, high-pitched, metallic clicks are characteristic, and they call incessantly from ponds and vleis during the breeding season. Choruses start calling in the late afternoon and continue well into the hours of darkness, until around midnight. The loud, tinny noise is produced by this otherwise tiny caco using a vocal sac that almost doubles the size of the frog’s body when it expands! 

They are common frogs in the St Francis area and widespread throughout South Africa. They occur in many different habitats in our area, including fresh water marshes, temporary pools, pastureland, seasonally flooded agricultural lands, rural gardens and ponds. Mostly they favour open areas with short vegetation, particularly grassy patches.

They vary in colour from emerald-green to light and dark brown, and sometimes they have spots or stripes, or can simply be uniform in colour. The underside is pale and has diagnostic grey to black spots that are concentrated more towards the back legs (compare to Bronze Caco).

The species breeds in almost any small, temporary water body, including pools in inundated grasslands, culverts and other rain-filled depressions. Females lay clutches of about 250 eggs that are attached to vegetation below the surface of the water. The tadpoles usually hatch two days later, and metamorphosis is completed within approximately two weeks, making for a very rapid change from egg to young adult. 

Boettger’s Caco feeds on termites and other small insects. It is thought to be an important predator of mosquitos and is, in turn, prey for birds, snakes and other frogs. It is a supreme generalist and adapts well to disturbance, even tolerating water that is moderately stagnant or polluted. It has the unusual habit of pretending to be dead when handled: it lies motionless for a brief time after being released.

10. Bronze Caco (Cacosternum nanum), Dwarf Dainty Frog, Koperblikslanertjie

Bronze Caco

(Photo credit: Marius Burger; https://www.inaturalist.org/photos/87129063)

These frogs are similar to Boettger’s Cacos, but differ in that they are usually grey or brown in colour, with a beautiful bronze tinge to their backs. They have grey to black spots on their white bellies, the spots being distributed more towards the front and sides of the body, rather than to the rear of the body, as in Boettger’s Cacos. They are also tiny frogs, measuring no more than 25 mm in length. 

This species is distributed from Swellendam in the Western Cape, eastwards along a narrow (70 km wide) coastal strip all the way to Gqeberha (Port Elizabeth), and particularly favours areas of higher rainfall. Around St Francis, Bronze Cacos are common in fynbos, grassland, thicket and forest biomes, where they breed in small ponds, dams, vleis, streams, rain pools alongside roads, and inundated grass and pasture.

The males make a distinctive metallic ‘che-che-che’ call, followed by rapidly repeated clicks. They are territorial and may begin calling in the mid-morning on warm, drizzly days or after rain. Otherwise they start in the late afternoon and may continue well into the evening. Females lay eggs in clusters of 8–25 that are anchored to the substratum. Previous researchers have reported that metamorphosed froglets of C. nanum leave the water 17 days after hatching, which may be the quickest growth to metamorphosis known in any frog.

In captivity, Bronze Cacos feed on mosquitoes and probably play an important role in controlling small insects in many habitats. They are one of the most common frogs in the St Francis area and, after rains, they can be heard calling from almost every rut, drainage ditch and small pond. In dry times, they are known to aestivate (become dormant) underground or below logs or rocks, and will sometimes emerge in large numbers after heavy rain.

11. Cape River Frog (Amietia fuscigula), Kaapse Rivierpadda

Photo credit:  – Gregg Darling, Oyster Bay;

(https://thebdi.org/2022/03/27/cape-river-frog-amietia-fuscigula/)

The Cape River Frog is found mostly in the Western Cape but its distribution does just squeeze into the very western regions of the Eastern Cape, including the St Francis area. It is a fairly large, typical frog with a snout-to-vent length of up to 125 mm. It has variable colouration, ranging from dark- through light-brown, but is also commonly green or olive, or brown with green streaks. It has a powerful, athletic build with long hind legs and feet, perfect for leaping, but also well webbed for powerful swimming. The forefeet are not webbed.

In the St Francis area, Cape River Frogs inhabit water bodies in grassland and fynbos habitats. If you walk along a stream or water course and hear a “bloep” sound, and see ripples on the surface of the water, you have most likely just startled a Cape River Frog that has jumped into the water to escape your attention. These frogs tolerate some habitat disturbance and are frequently found associated with human habitation. They happily colonise farm dams, ditches and ponds.

The adults spend the day floating amongst vegetation or basking on rocks above the water. Larger individuals may be found on the banks or in the vegetation above the water. They readily leap to the safety of the nearest pool when disturbed.

Breeding takes place in shallow water along the edges of pools, dams, streams and slow-flowing rivers. These frogs breed in standing water, where the females lay clutches of 400–500 eggs.

Cape River Frogs feed on numerous types of flying and crawling insects and are, in turn, an important food source for otters, larger birds and snakes.

12. Delalande’s River Frog (Amietia delalandii), Delalande se Rivierpadda

Photo credits: 

 Hankey Andrew (https://vmus.adu.org.za/vm_view_record.php?vm=FrogMAP-125)

Delalande’s River Frog is also a typical river frog, just like the previous species, and has a pointed snout with eyes that protrude past the outline of the head. It has long, strong legs with extensively webbed feet. Adult females reach a maximum size of around 90 mm, while males reach around 60 mm in length; this makes the species somewhat smaller in size than the Cape River Frog.

Delalande’s River Frogs favour savanna and forest biomes, along with forest fringes, and are always found close to fresh water, usually along the banks of large or small streams. They are widely dispersed in the eastern regions of South Africa, as well as along the south western coastal areas of the Eastern Cape. They are frequently associated with human habitation and take up residence in ditches and ponds, often where reeds and water lilies are present.

They are typically varied in colour, from a dull brown to a luminous green, with dark chocolate blotches and orange flecks on their backs. About half the individuals have a prominent pale vertebral stripe running from the snout down the middle of the back.

The adults love to float around on the surface of a pond, in amongst the vegetation, or to bask on rocks on the bank. They rapidly escape to the safety of the water if disturbed, making a characteristic “bloep” sound as they disappear under the water; they may remain submerged and out of sight for long periods of time.

These river frogs are active throughout the year and may breed at any time. Females lay clutches of 400–500 eggs in shallow, standing water. Tadpoles may grow to 80 mm in length and tend to feed on detritus at the bottom of the pond.

Being a species that is numerous and active all year round, Delalande’s River Frogs consume a lot of insects. They also form important prey for other creatures, such as herons, water mongooses and snakes.

13. Striped Stream Frog (Strongylopus fasciatus), Gestreepte Langtoonpadda 

This is an attractive little frog with silver-yellow to brown colouring and two dark stripes on the back. It also has a characteristic dark facial stripe that runs through the eye. The head is pointy and the toes are very long, almost the length of the body, with no webbing between them (this distinguishes them from river frogs). This frog has a white belly and the males have yellow throats. The maximum size of an adult is around 50 mm.

Striped Stream Frogs are endemic to southern Africa and are widespread and common in the St Francis area, where they inhabit fynbos, thicket and grassland biomes, but are never very far from permanent water.

They prefer open, grassy or well vegetated streams or ponds and tend to breed in winter. Breeding seems to be associated with a drop in temperature, but males can be heard calling any time of the year. Their high-pitched, sharp “pip-pip-pip” call is very characteristic and can be used to identify them. They may even start calling after a cold front passes by, even if it is not winter breeding time.

At some breeding sites only a few calling males may be present, while at others, large choruses may form, with calling males separated from each other by only a few centimetres. Males call from the water’s edge or from elevated positions in reeds and grass.

The eggs are laid in shallow water on the edges of grassy pools, streams and man-made dams. They soon become camouflaged as debris sticks to them, and they are difficult to see. The tadpoles complete their metamorphosis in 4–5 months.

14. Clicking Stream Frog (Strongylopus grayii), Kliklangtoonpadda

Clicking Stream Frog

Photo credit: Chad Keates (https://nextgenherpetologist.co.za/2019/02/22/frogs-of-the-eastern-cape/)

This beautiful frog has dark blotches over its back and a characteristic pale line that stretches down the centre of the back, all the way from the snout to the posterior end of the body. Other than this stripe, which may be broad or narrow, the frog is very camouflaged by its spots and blotches, and even its eyes are disguised by the presence of dark facial stripes running through the horizontal pupils.

Adults attain a length of around 50 mm and have an extremely long fourth toe on each back foot. There is reduced webbing between the toes, which distinguishes these frogs from the river frogs. As its name suggests, the clicking stream frog makes and a distinctive “clik-clik-clik” call that is not dissimilar to the sound of a gutter dispensing large drops of water onto a sodden surface below. Males may call throughout the day and night after good rains have fallen.

This species is endemic to southern Africa and is common in the St Francis area. It inhabits the fynbos biome, where it can be found in any marshy or wet areas. It also makes its home in the thicket and forest biomes, and even lives comfortably in areas close to the coast. It shows a wide tolerance for water quality and will breed in brackish pools where sea spray is prevalent. Mostly, though, it prefers to breed in small dams, ponds, pools, ditches and shallow seeps.

Clicking stream frogs breed when it rains and waterbodies are plentiful. The females lay about 250–350 eggs, usually out of the water, up to 30 cm from its edge. The eggs are deposited in moss, under leaves, on mud or in crevices under rocks. In wet weather, tadpoles emerge from the egg capsules after 5 days and enter the water, but in dry weather they can survive in the capsules for as long as 63 days. Development to the adult stage takes place over a period of 3–6 months.

Clicking stream frogs are active all year round and feed mostly on small insects.

15. Cape Sand Frog (Tomopterna delalandii), Gestreepte Sandpadda

Originally, sand frogs were grouped with Giant Bullfrogs and were referred to as small pixies. Only later were they placed in their own genus, Tomopterna. The Cape Sand Frog is reminiscent of a small toad because of its warty skin and the way it walks. It has a squat, robust body that is almost as wide as it is long, and a broad head with large, bulging eyes. The legs are short and there is a curious, spade-like structure on each heel that is used to dig into the sand. Females can reach 50 mm in snout-to-vent length.

The colouration of these frogs varies from light grey to dark brown, but they usually have a mottled appearance and are, well, pretty much sand-coloured. Some individuals have a pale patch between the shoulders, and most have a distinctive pale vertebral stripe all the way down the middle of the back. Males have a dark throat.

These frogs are endemic to South Africa and occur along the western and southern coastal regions as far east as Port Alfred. They are found in lowlands and valleys throughout the fynbos biome and favour sandy areas. They are also commonly found in agricultural lands, particularly if the substratum is sandy. They hibernate for most of the year, digging themselves into the sand and remaining underground until the first rains of the year arrive.

Cape Sand Frogs breed in pans, vleis and dams, and in small watercourses in flat, sandy areas. They can breed whenever rain has fallen and females will lay up to 2 500 eggs, either singly or in small masses, in shallow water. The eggs have an unpleasant odour, doubtless to deter would-be predators from consuming them. The tadpoles reach 44 mm in length and metamorphose into small frogs within 25–35 days.

References

https://www.frogmap.adu.org.za

https://www.thebdi.org

https://www.inaturalist.org

 https://nextgenherpetologist.co.za/2019/02/22/frogs-of-the-eastern-cape/

https://www.tyroneping.co.za

 https://en.wikipedia.org 

 https://www.steenboknaturereserve.org.za/fauna/frogs

Endangered Wildlife Trust: https://www.youtube.com/watch?v=J1Sc78-TOFs

Quick Photographic Guide

Thank you to Chad Keates, Nextgenherpetologist, for allowing use of some the beautiful photos in this quick guide (nextgenherpetologist.co.za)

A) TOADS

B) REED FROGS

C) RAIN FROG

D) CLAWED FROG

E) CACOS

RIVER FROGS

STREAM FROGS

SAND FROG