Knysna Banana Frog
Encyclopedia
The Knysna Banana Frog (Afrixalus knysnae) is a species of frog
in the Hyperoliidae
family.
It is endemic to South Africa
.
s are temperate forest
s, Mediterranean-type shrubby vegetation, freshwater marsh
es, intermittent freshwater marches, arable land
, water storage areas, and pond
s.
It is threatened by habitat loss.
The Knysna Banana Frog is a species known from around 7 locations at low altitude (< 250 m asl) on the south coast of South Africa on either side of the border between the Eastern Cape and Western Cape Provinces. To the extent of scientists knowledge we know that the occurrence rate is 1,756 km². The area of occupancy has not been formally calculated but is known to be declining as some sites (like Covie) are presumed lost as no adults or tadpoles have been found there for at least three years. Although some sites are pristine, others are threatened by alien vegetation. Banana frogs are native to South Africa (Eastern Cape Province, Western Cape Province).
Knysna Banana Frogs are Terrestrial; Freshwater amphibians. They live in coastal mosaic of vegetation types, including mountain fynbos heathland, and forest. The frogs breed in small dams and shallow semi-permanent water with much emergent vegetation and even in well vegetated ornamental garden ponds; it is suspected that this species requires high water quality for breeding.
Habitat is declining due to encroachment by urban development, alien invasive vegetation and chemical pollution. Species in this genus deposit between 20 and 50 eggs on vegetation above the water. Tadpoles emerge, drop into the water and remain there until metamorphosis.
List of Habitats
1 Forest
1.4 Forest - Temperate
3 Shrubland
3.8 Shrubland - Mediterranean-type Shrubby Vegetation
5 Wetlands (inland)
5.7 Wetlands (inland) - Permanent Freshwater Marshes/Pools (under 8ha)
5.8 Wetlands (inland) - Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha)
14 Artificial/Terrestrial
14.1 Artificial/Terrestrial - Arable Land
15 Artificial/Aquatic & Marine
15.1 Artificial/Aquatic - Water Storage Areas (over 8ha)
15.2 Artificial/Aquatic - Ponds (below 8ha)
The distribution of the species tends to be severely fragmented as no one site holds more than 50% of the individuals and the distances between subpopulations are too great for dispersal within one generation. When scientists visited a site at Covie they found that the frogs have not produced any individuals (adults or tadpoles) for three years. It seems likely that this subpopulation has become extinct, but further visits are required to substantiate this; just because this area seems to be extinct does not mean the entire species is extinct. The cause for this disappearance is as yet unknown, but change in water quality is suspected as a possible reason. The change in water quality is most likely due to urbanization.
The main threat is habitat loss due to urban and recreational development, afforestation, invasive vegetation, agricultural expansion and chemical pollution. These threats are likely to act locally on breeding sites. Drought may cause additional stresses for this species.
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
in the Hyperoliidae
Hyperoliidae
Hyperoliidae is a family of small to medium sized, brightly colored, frogs which contains more than 250 species in 19 genera. Seventeen genera are native to sub-Saharan Africa. In addition,the monotypic genus Tachycnemis occurs on the Seychelles Islands, and the genus Heterixalus is endemic to...
family.
It is endemic to South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
Habitat
Its natural habitatHabitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s are temperate forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s, Mediterranean-type shrubby vegetation, freshwater marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es, intermittent freshwater marches, arable land
Arable land
In geography and agriculture, arable land is land that can be used for growing crops. It includes all land under temporary crops , temporary meadows for mowing or pasture, land under market and kitchen gardens and land temporarily fallow...
, water storage areas, and pond
Pond
A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens, water features and koi ponds; all designed for aesthetic ornamentation as landscape or architectural...
s.
It is threatened by habitat loss.
The Knysna Banana Frog is a species known from around 7 locations at low altitude (< 250 m asl) on the south coast of South Africa on either side of the border between the Eastern Cape and Western Cape Provinces. To the extent of scientists knowledge we know that the occurrence rate is 1,756 km². The area of occupancy has not been formally calculated but is known to be declining as some sites (like Covie) are presumed lost as no adults or tadpoles have been found there for at least three years. Although some sites are pristine, others are threatened by alien vegetation. Banana frogs are native to South Africa (Eastern Cape Province, Western Cape Province).
Knysna Banana Frogs are Terrestrial; Freshwater amphibians. They live in coastal mosaic of vegetation types, including mountain fynbos heathland, and forest. The frogs breed in small dams and shallow semi-permanent water with much emergent vegetation and even in well vegetated ornamental garden ponds; it is suspected that this species requires high water quality for breeding.
Habitat is declining due to encroachment by urban development, alien invasive vegetation and chemical pollution. Species in this genus deposit between 20 and 50 eggs on vegetation above the water. Tadpoles emerge, drop into the water and remain there until metamorphosis.
List of Habitats
1 Forest
1.4 Forest - Temperate
3 Shrubland
3.8 Shrubland - Mediterranean-type Shrubby Vegetation
5 Wetlands (inland)
5.7 Wetlands (inland) - Permanent Freshwater Marshes/Pools (under 8ha)
5.8 Wetlands (inland) - Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha)
14 Artificial/Terrestrial
14.1 Artificial/Terrestrial - Arable Land
15 Artificial/Aquatic & Marine
15.1 Artificial/Aquatic - Water Storage Areas (over 8ha)
15.2 Artificial/Aquatic - Ponds (below 8ha)
Identification
The Knysna Banana Frog is creamy and yellow color with lateral brown stripes. The females have a smooth texture.Population
Population trends are unknown, since there has been a rapid decline in population it is hard to tell if urban development, alien invasive vegetation, chemical pollution, or a combination of these things have been the sole reason of the decline and therefore affecting the population trend.The distribution of the species tends to be severely fragmented as no one site holds more than 50% of the individuals and the distances between subpopulations are too great for dispersal within one generation. When scientists visited a site at Covie they found that the frogs have not produced any individuals (adults or tadpoles) for three years. It seems likely that this subpopulation has become extinct, but further visits are required to substantiate this; just because this area seems to be extinct does not mean the entire species is extinct. The cause for this disappearance is as yet unknown, but change in water quality is suspected as a possible reason. The change in water quality is most likely due to urbanization.
The main threat is habitat loss due to urban and recreational development, afforestation, invasive vegetation, agricultural expansion and chemical pollution. These threats are likely to act locally on breeding sites. Drought may cause additional stresses for this species.
Conservation Actions
Among frogs this species is the most threatened and needs the most help. There are many important questions that are still unanswered; however the most important things we need to concentrate on now is what effects take place on the frogs when the water quality changes. Less urban development, alien invasive vegetation, and chemical pollution will help the frog population thrive but it will not totally stop the extermination of this population.Source
- South African Frog Re-assessment Group (SA-FRoG) & IUCN SSC Amphibian Specialist Group 2010. Afrixalus knysnae. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4.
. Downloaded on 16 November 2010.
- Minter, L. &Schiøtz, A. 2004. Afrixalus knysnae. 2006 IUCN Red List of Threatened Species. Downloaded on 22 July 2007.