Hyperolius viridiflavus, or African reed frogs, are a widespread species that occupy most suitable habitats (ponds and lakes) throughout northwestern Ethiopia, through Southern Sudan to western Kenya, Rwanda, Uganda, Burundi, northwestern Tanzania, northeastern Democratic Republic of Congo, and most likely eastern Central African Republic.
Biogeographic Regions: ethiopian (Native )
Hyperolius viridiflavus has a bright warning coloration that wards off predators. Dragonfly larvae, beetle larvae, turtles, ray-finned fish and water snakes eat the tadpoles of H. viridiflavus.
Known Predators:
Anti-predator Adaptations: aposematic
Hyperolius viridiflavus is a highly variable species that exhibits considerable polymorphism in color pattern. Some populations contain distinct morphs while in others there is gradation among extremes. It is widely regarded as a superspecies with more than fifty subspecies recognized. The subspecies are divided into two subgroups, parallelus and viridiflavus, based on variation in geographic range and coloration. There is some controversy about the taxonomy of H. viridiflavus that is discussed further in the other comments section.
Hyperolius viridiflavus is a small to medium sized frog species with an average mass of 2 g and body length of 15 to 30 mm, depending on the subspecies.
This species exhibits sexual dimorphism with males slightly smaller than females. Females are more colorful than males; their adult pattern is referred to as Phase F which is highly variable and contains several distinct morphs. Mature males frequently remain in the juvenile phase (Phase J), which ranges from brownish to green with paired light dorsolateral lines.
Members of this species have horizontal pupils, extensive webbing of the feet, a brief snout, and a very large, shagreened, gular flap. They lack an external metatarsal tubercle. Males have a large dilatable vocal sac. Females have a tranverse gular flap All subspecies have a subdermal dark bluish lateral streak caused by black pigmentation of the musculus obliquus abdominal muscle. This band is sometimes difficult to see if the sides of the frog are heavily pigmented. The band differs in placement between the sexes.
The subspecies have different coloration ranging from solid light green in the H. viridiflavus mwanzae to light brown in H. viridiflavus pantherinus to very brightly spotted and striped in H. viridiflavus tauniatus. The feet are frequently brightly colored.
Average mass: 2 g.
Range length: 14 to 33 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; polymorphic
Sexual Dimorphism: female larger; sexes colored or patterned differently; female more colorful
Hyperolius viridiflavus lives in an environment with widely fluctuating weather conditions. Shortly after the breeding season, these frogs face a severe dry season when they must rely on stored water. Adults do not handle this water shortage as well as juveniles. Adults do not generally survive the dry season, and in areas with prolonged dry seasons adults are probably annual. Linsenmair has never found an adult H. viridiflavus nitidulus that has survived the dry season in West Africa. Even under laboratory conditions, adult H. viridiflavus senesce quickly after the end of breeding activity. Males also experience high mortality because they are highly vocal and are therefore more susceptible to predation by acoustically-hunting predators.
Typical lifespan
Status: wild: 1 (high) years.
Hyperolius viridiflavus lives in the tropical African savanna. It is associated with emerging vegetation in savanna, grasslands, and at the margins of forests, lakes, rivers, and swamps, where these frogs may live in high densities. Hyperolius viridiflavus also lives in areas associated with humans, like cultivated land and gardens. This species breeds in a variety of aquatic habitats from very small to large ponds that may be permanent but are usually temporary. It ranges from low altitudes to 2,400 m in Ethiopia.
Range elevation: 2,400 (high) m.
Habitat Regions: tropical ; terrestrial ; freshwater
Terrestrial Biomes: savanna or grassland ; rainforest
Aquatic Biomes: lakes and ponds; rivers and streams; temporary pools
Wetlands: marsh ; swamp
Other Habitat Features: agricultural ; riparian
The taxonomy of Hyperolius viridiflavus is complex and has been the subject of much debate. Much of the difficulty has come from the dependence on dorsal color patterns as taxonomic characters. Schiøtz argues that H. viridiflavus is a superspecies with many subspecies that can be divided into two subgroups, parallelus and viridiflavus based on coloration and geographic range. Wieczorek has broken up the various subspecies of H. viridiflavus into ten full species based on mitochondrial DNA. Adult H. viridiflavus are unique because they can regenerate fully functional digits after amputation.
Hyperolius viridiflavus are insectivores that feed on many different types of insects including flies in the genera Drosophila, Musca, Phormia, Lucilia, and Calliphora. The free-living tadpoles of Hyperolius viridiflavus nitidulus eat algae.
Animal Foods: insects
Plant Foods: algae
Primary Diet: carnivore (Insectivore )
Hyperolius viridiflavus is a predator of insects in the African savanna. It is also the prey of several species of animals.
This species is a part of the international pet trade although not at high levels.
Positive Impacts: pet trade
There are no known adverse effects of Hyperolius viridiflavus on humans. However, the Masai of East Africa have a superstition that their cattle will die if they eat these frogs because of their bright warning coloration.
Hyperolius viridiflavus eggs hatch into tadpoles two to five days after laying, depending on the temperature of the water. Tadpoles take eight weeks to metamorphose into juveniles. Juveniles mature sexually in three to twelve months depending on the climate. Juvenile H. viridiflavus have a different coloration than adults, referred to as Phase J, which is light brown to green in color. Sexually mature males frequently maintain the juvenile coloration throughout adulthood. Phase F, the adult phase, is a highly variable color pattern with distinct morphs.
Development - Life Cycle: metamorphosis
Hyperolius viridiflavus is listed as least concern by the International Union for Conservation of Nature because of its very wide distribution and tolerance of a broad range of habitats. It also likely has a large population size with no significant threats. This species is occasionally found in the international pet trade, but not at a high enough level to pose a threat to it.
CITES: no special status
IUCN Red List of Threatened Species: least concern
Hyperolius viridiflavus has a melodic call like a xylophone that is more tonal than that of other species in this genus. Their calls are a characteristic part of the African night sounds. Males have an exposed calling site and form choruses in order to attract mates.
Hyperolius viridiflavus nitidulus males have two distinct calls, a mating call and a territorial call. The territorial call is longer and deeper than the mating call, and lasts from 0.28 to 0.36 seconds and has a frequency of 0.98 to 2.6 kHz. The mating call is a short metallic click that lasts between 0.10 to 0.24 s and has a frequency of 2.04 to 3.43 kHz, depending on the size of the frog. Female H. viridiflavus cannot make sounds.
Members of this species use keen visual perception in order to capture insects. They have bulging eyes and horizontal pupils.
Communication Channels: acoustic
Other Communication Modes: choruses
Perception Channels: visual ; acoustic
Hyperolius viridiflavus breeds during the wet season. The length of the breeding activity varies among subspecies but typically lasts several months. This species is polygynandrous. At the beginning of the breeding season, males migrate to bodies of water such as shallow ponds and form calling choruses to attract mates. Males maintain an individual calling space through combat. Males typically call at dusk and expend considerable energy trying to attract a mate. Females H. viridiflavus may select larger males as mates. Females approach males and initiate amplexus. Amplexus is axillary (the male holds the female around the armpits). The eggs are laid on vegetation under the water in ponds, lakes, and slow-moving streams. Female H. viridiflavus produce multiple clutches during the breeding season.
Mating System: polygynandrous (promiscuous)
Hyperolius viridiflavus breeds during the wet season. The length of the breeding activity varies among subspecies but typically lasts several months. Females have multiple clutches over the course of the breeding season. The average size of a clutch is 330 eggs. Eggs hatch after 2 to 5 days, and have metamorphosed into juveniles by 8 weeks of age. Juveniles of both sexes become sexually mature at 4 to 12 months old.
Hyperolius viridiflavus has been shown to experience protogyny, or female to male sex change, in the laboratory. The new males were able to fertilize the eggs of females. This likely occurs when the sex ratio within a population is heavily weighted towards males.
Hyperolius viridiflavus is semelparous, but may breed multiple times in its one breeding season. This reproductive strategy is largely due to climatic factors, as no adults have been documented surviving the annual, harsh dry season. Even in laboratory settings, individuals will senesce shortly after the breeding season.
Breeding interval: Female Hyperolius viridiflavus produce a new clutch every 10 to 20 days during the breeding season.
Breeding season: Hyperolius viridiflavus breed during the wet season which typically lasts several months.
Range number of offspring: 94 to 800.
Range time to hatching: 2 to 5 days.
Range age at sexual or reproductive maturity (female): 4 to 12 months.
Range age at sexual or reproductive maturity (male): 4 to 12 months.
Key Reproductive Features: semelparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
Hyperolius viridiflavus provides no parental investment other than yolk and sperm for the eggs.
Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)
The common reed frog (Hyperolius viridiflavus) is a species of tree frogs in the family Hyperoliidae found in Burundi, the Democratic Republic of the Congo, Ethiopia, Kenya, Rwanda, Sudan, Tanzania, and Uganda, and possibly the Central African Republic, Chad, and Eritrea. Its natural habitats are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, dry savanna, moist savanna, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, subtropical or tropical seasonally wet or flooded lowland grassland, subtropical or tropical high-altitude grassland, rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, freshwater springs, arable land, pastureland, rural gardens, urban areas, heavily degraded former forests, water storage areas, ponds, irrigated land, seasonally flooded agricultural land, and canals and ditches.
Some evidence suggests that west African frogs may change sex from female to male after having successfully bred.[2] Animals that switch sex as adults are known as sequential hermaphrodites because they have the gonads of either sex but at different periods of their lives. This contrasts with animals which are "simultaneous hermaphrodites" which have both gonads at the same point. However, this sequential hermaphroditism in reed frogs has only been noted once and in a captive colony; it is not generally accepted by scientists that this process occurs in amphibians. Despite a lack of evidence for hermaphroditism, the film Jurassic Park has become a cultural reason for why many believe that frogs can be sequential hermaphrodites.
The common reed frog (Hyperolius viridiflavus) is a species of tree frogs in the family Hyperoliidae found in Burundi, the Democratic Republic of the Congo, Ethiopia, Kenya, Rwanda, Sudan, Tanzania, and Uganda, and possibly the Central African Republic, Chad, and Eritrea. Its natural habitats are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, dry savanna, moist savanna, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, subtropical or tropical seasonally wet or flooded lowland grassland, subtropical or tropical high-altitude grassland, rivers, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, freshwater springs, arable land, pastureland, rural gardens, urban areas, heavily degraded former forests, water storage areas, ponds, irrigated land, seasonally flooded agricultural land, and canals and ditches.
Some evidence suggests that west African frogs may change sex from female to male after having successfully bred. Animals that switch sex as adults are known as sequential hermaphrodites because they have the gonads of either sex but at different periods of their lives. This contrasts with animals which are "simultaneous hermaphrodites" which have both gonads at the same point. However, this sequential hermaphroditism in reed frogs has only been noted once and in a captive colony; it is not generally accepted by scientists that this process occurs in amphibians. Despite a lack of evidence for hermaphroditism, the film Jurassic Park has become a cultural reason for why many believe that frogs can be sequential hermaphrodites.
Hyperolius viridiflavus tree frog from Lubumbashi, Democratic Republic of Congo