Bradypodion

Bradypodion(meaning "slow-footed" inGreek) is agenusofchameleonsin thefamilyChamaeleonidae, collectively calledSouth African dwarf chameleons. All species are found inSouth Africaand most areendemicto this country, but a few can also be found inEswatini,Lesotho, southernmostNamibiaand possibly southernmostMozambique. They are quite small chameleons where the different species often can be difficult to separate by appearance, although exact location (each species tends to have a rather small distribution) and the intense breeding colours of males are useful for their identification. They arearboreal, but some species are mostly found low in the vegetation.
Bradypodionfeed on small invertebrates, especially insects.They rapidly reach sexual maturity, typically at an age between half a year and one year, but sometimes up to two years.Adult males areterritorial.It is the only genus of chameleon where females of all species give birth to live young rather than lay eggs (the only other chameleons that give birth to live young are certainTriocerosspecies). This is likely an adaption to the relatively cold climate of southern Africa in comparison to tropical Africa. Colder temperatures slow the development of eggs laid in the ground; when instead retained inside the body until birth, a female can actively sun bask to increase the temperature.A female can give birth to up to 20 young per time, twice or rarely even three times in a year.
Up until the early 2000s, some other chameleons from eastern and central Africa were occasionally placed herein, but they are now placed inKinyongiaandNadzikambia.
20 species are currently recognized:
Delimitation ofBradypodionhas been controversial for some time. Most species seem readily distinguishable bymorphologicalcharacteristics, but for some time the genus was used as awastebin taxonfor smaller chameleons fromsub-Saharan Africawithplesiomorphichemipenises.Alternatively, many of the present species were reduced to subspecies status.This has since been refuted,but several more species seem recognizable judging from morphologicalandmitochondrial16S rRNAandNADH dehydrogenasesubunit2sequencedata.
Thephylogenyandbiogeographyof this group is quite consistently resolved. TheCape dwarf chameleonand theKnysna dwarf chameleon(and possibly one new species close to it) arebasallineages with unclear relationships; they seem a bit closer to each other than to any other species, but altogether are quite distant. They occur in isolated ranges in coastalWestern Capeand westernEastern Capeprovinces. Inhabiting a wide range ofhabitats, they are (for the genus) large, and have brilliant, predominantly green coloration and long tails - just as in manyChamaeleo. These characters areplesiomorphic, retained from the genus' ancestor.
The remaining species form a well-supportedclade, which in turn can be divided into smaller groups. One consists of forms that radiated on the seawards slopes of theDrakensberg Mountains: the southernDrakensberg dwarf chameleon, the northernTransvaal dwarf chameleon, and what appears to be undescribed species from theNgome Foreston the southeastern slopes. These are also plesiomorphic inhabitusand habits.
Another group of taxa occurs from easternmost Eastern Cape to centralKwaZulu-Natalprovinces, betweenGilboa Forestand theTugela River. These inhabit a wide range of habitat and contain the plesiomorphicNatal Midlands dwarf chameleonfrom thenamesake region, the smallblack-headed dwarf chameleonwhich inhabitsfynbosand other low forest on slopes of mainly coastal KwaZulu-Natal, and another probable new species from the Gilboa Forest area. These appear to be a quite recentradiationfrom a single ancestor, and the group requires more research as regards species limits, and geographical delimitation from the Drakensberg dwarf chameleon.
Several largish but short-tailed andcryptictaxa inhabit morearidhabitatssuch askaroo. TheKarrooandsouthern dwarf chameleonsseem to have considerablegene flowrange fromNorthern Capeto coastal Eastern Cape provinces. The small and nearlyextinctSmith's dwarf chameleonis close to these; it occurs on theescarpmentinland fromJeffreys Bay. Less closely related is theRobertson dwarf chameleon, another aridland species which is found in Western Cape province inland from the range of the Cape dwarf chameleon and may be acryptic species complex, and an undescribed population from theSwartberg Mountains.The last species with aridlandapomorphies, theNamaqua dwarf chameleon, is quite distant to the others; it occurs in coastal regions from north of the Cape species throughNamaqualand. This is probably still a part of a single radiation which brought about all the aridland taxa, and eventually Smith's dwarf chameleon.
The remaining species are all small inhabitants of forested slopes and fynbos, such as the black-headed and Smith's dwarf chameleons. However, as already indicated by the distinctness of these two, their morphologies seem to be aconvergentadaptation. TheKentaniandTranskei dwarf chameleonsfrom the east coasts of Eastern Cape may or may not be each other's closest relatives.Setaro's dwarf chameleonfrom northeastern coastal KwaZulu-Natal is not close to these. TheZululand dwarf chameleonfrom westernuThunguluapparently consists of two or more species, one that may be closer to the preceding, and one that might be an early offshoot of the ancestral Drakensberg stock, and which are distinguishable by morphological and mtDNA characteristics.
In conclusion, of the three basic morphotypes found in this genus, one (bright, long-tailed, large) is plesiomorphic, another (large, short-tailed, drab) apparently only evolved once, and the third (the small, slope-inhabiting forms) are convergent in morphology. The ancestors ofBradypodionthus were mid-sized chameleons with vivid color, which settled the Cape region from roughly north-northwestwards. Due toclimate changeswith fluctuatingaridity, the basal lineages inhabiting humid fynbos in the southwest became isolated from each other and from the animals living around the border region between Northern and Eastern Cape andFree State, andLesotho. The aridland habitat fluctuates in extent during climate shifts, and mountainous habitat becomes fragmented or consolidates accordingly. Consequently, the Drakensberg, theB. thamnobates-B. melanocephalum, and the aridland group, as well as several coastal lineages, diverged and evolved to their present-day ranges and diversity.