What influences colour patterns in chameleons

What influences colour patterns in chameleons

Science

Chameleons are known for their ability to change colour. International scientists have now investigated what exactly influences different colour patterns in different populations. They want to know to what extent the habitat itself, the distance to other populations or social interactions influence the colour change.

The test subjects were European chameleons (Chamaeleo chamaeleon) caught in La Herradura and Sanlúcar in Spain. The two regions are around 230 kilometres apart. Other Chamaeleo chameleon were collected in the north-western Negev and on the Carmel coast in Israel (around 180 km apart). On the other hand, flap-necked chameleons (Chamaeleo dilepis) were captured in Simbithi, Zulu Falls and Maduma Boma in South Africa. The three locations are between 100 and 550 kilometres apart.

Each chameleon was subjected to two experiments. In the first, the scientists let the chameleon walk two metres on a horizontal stick, which was placed in the sun about one metre above the ground. In the second experiment, a second chameleon of the same species was placed on the same stick 50 cm away from the first. The colour patterns shown by the animal during the experiments and its behaviour were recorded for 20 minutes. The data was then analysed using computer programs. Blood was taken from a cut claw of all chameleons and genetically analysed. The habitats and soil conditions were also analysed in various ways and statistically evaluated. The captured animals were kept in ventilated plastic cages for a maximum of 12 hours and released after the analyses. Unfortunately, the study does not mention how many chameleons were caught and released in total.

As expected, it turned out that the individual populations of both the European and the flap-necked chameleon differed genetically from each other. The populations of Chamaeleo dilepis had significantly different haplotypes.

In the flap-necked chameleon, the females were significantly larger than the males in two locations, but not in Simbithi. The scientists also found that the colour patterns of the three populations studied could be clearly distinguished from each other. They concluded from the results that the colour patterns in Chamaeleo dilepis are primarily dependent on genetic isolation. The habitat itself and the size of the chameleons did not influence the colour patterns.

In the European chameleon, however, the situation was different: Body size and genetic distance to other populations predicted colour patterns in males very well. However, the colour patterns were independent of the location where the animals were found. Soil or vegetation colours only had a minor influence on the colour of females.

Genetic and behavioural factors affecting interpopulation colour pattern variation in two congeneric chameleon species
Tammy Keren-Rotem, Devon C. Main, Adi Barocas, David Donaire-Barroso, Michal Haddas-Sasson, Carles Vila, Tal Shaharabany, Lior Wolf, Krystal A. Tolley, Eli Geffen
Royal Society Open Science 11: 231554
DOI:  0.1098/rsos.231554

Chamaeleo dilepis in traditional south african medicine

Chamaeleo dilepis in traditional south african medicine

Science

Researchers from North-West University in South Africa have investigated which reptiles are used by traditional healers and how much they actually know about the species used. They visited six medical shops and markets (muthi shops/markets) in Polokwane, Pretoria, Johannesburg, Pietermaritzburg and Durban. Twelve traditional healers were also visited, two each in Limpopo and Gautend and seven in KwaZulu-Natal. Healers who agreed to be interviewed were asked about the species and origin of reptiles they use. Samples were taken for genetic testing from 111 carcasses and tissue remains (some only bones with meat remains) offered for sale.

Of the 34 reptile species known so far from the literature to have been traditionally used in South African medicine, nine could be confirmed. The healers reported that they partly hunted the reptiles themselves and partly bought them from specialised hunters. To the astonishment of the researchers, reptiles killed in road traffic (“roadkills”) were also used by healers. For sale and use, the reptiles were preserved. Fat and internal organs were removed manually. The fat was kept in bottles as it could be sold individually. The organs were not used further. The carcasses of the reptiles were then rubbed with ash and salt and dried in the sun. All healers agreed that whole carcasses were rarely sold – usually customers only wanted to purchase certain body parts, as only these were known for their effects.

The flap-necked chameleon was already known to be an occasional species at traditional South African healer markets. Several Chamaeleo dilepis were also identified in this study, but they were only marketed with an umbrella term in isiZulu. Unwabu refers to any species of chameleon, not specifically Chamaeleo dilepis. For other reptile species, some of the healers’ names matched the identified species down to the species level. However, there were also quite a few misidentified specimens where completely different reptiles were identified by the healers than turned out to be the case in the genetics.

Barcoding and traditional health practitioner perspectives are informative to monitor and conserve frogs and reptiles traded for traditional medicine in urban South Africa
Fortunate Phaka, Edward Netherlands, Maarten van Steenberge, Erik Verheyen, Gontran Sonet, Jean Hugé, Louis du Preez, Maarten Vanhove
Molecular Ecology Resources [Preprint], 2022
DOI: 10.22541/au.166487945.53921162/v1

Fieldguide to the Chameleons in Uganda

Fieldguide to the Chameleons in Uganda

Book publications
Kinyongia tolleyae, Rwenzori, Uganda

Good things come to those who wait. Already in 2019, the two biologists Dr Daniel Hughes and Dr Mathias Behangana had produced a field guide to the chameleons in Uganda. Hughes works at the Carnegie Museum of Natural History (Pittsburgh, Pennsylvania, USA), Behangana is one of Uganda’s leading herpetologists. But the worldwide corona pandemic put the project on an involuntary hiatus. Only now could 4000 copies of the field guide be distributed in Uganda.

The small field guide has 64 pages and is designed in a pocket format to be handy to take with you into the rainforest and savannah. The language of the field guide is English, which is the official language in Uganda along with Swahili. The field guide includes all 13 species of chameleons found in the landlocked East African country. Each species is presented with photos of the chameleons in their habitat, a distribution map and a detailed description. There is also a short preface with information on chameleons in general, for example, that, contrary to local myths, they are harmless to humans and useful flycatchers. The project was supported by Uganda Wildlife Authority, Wildlife Conservation Society (WCS), NatureUganda and US Agency for International Development (USAID. Ein Interview mit Dr. Daniel Hughes wird in Kürze in der CHAMAELEO erscheinen.

A pocket guide to the Chameleons of Uganda
Mathias Behangana, Daniel F. Hughes
64 pages, self-published
The PDF is available for free download here.

Hidden species within the genus Chamaeleo

Hidden species within the genus Chamaeleo

Science

Thanks to genetic studies, the identification of species is much more precise today than it was a few decades ago. However, genetics always raises new questions. The genus Chamaeleo currently has 14 species. Scientists from South Africa have now investigated whether there might be other ‘hidden’ species of the genus Chamaeleo. At the same time, they investigated where the origin of the genus Chamaeleo might lie. For this purpose, the genetic material of all 14 species recognised so far was examined. Exciting results came to light: of the fourteen Chamaeleo species, thirteen were confirmed, but one was questioned. In addition, several new candidate species were identified.

The two different populations of Chamaeleo anchietae in western Angola and in south-eastern Congo and Tanzania probably represent two different species. If the animals from the Democratic Republic of Congo and Tanzania were true to be elevated to species status in the future, they would have to be named Chamaeleo vinckei according to taxonomy and a species description from 1950.

Chamaeleo gracilis seems to hide – which would not be surprising due to its wide distribution – at least three independent species. The “real” Chamaeleo gracilis would be found in Liberia, Sierra Leone and Guinea. The other two groups originate from the triangle of countries between Chad, Cameroon and the Central African Republic and from the border between Kenya and Tanzania. Unfortunately, only single specimens of Chamaeleo gracilis have been sampled, so no more far-reaching recommendation on the splitting of species can be made at this point.

The flap-necked chameleon (Chamaeleo dilepis), currently described as a single species, could contain a total of three species. One of the genetically distinct populations occurs in eastern Africa in Tanzania and Rwanda, while a second species is found in southern and eastern Africa, from South Africa through Botswana, Zambia, Namibia, Mozambique and Malawi to southern Tanzania. The third species would be distributed in west central Africa between Angola and the Congo. None of the candidate species matches the eight subspecies described so far purely on the basis of appearance. Therefore, a complete review of the previous subspecies, their status and the species status of the three newly emerged clades is necessary.

The results of the study on Chamaeleo necasi from Benin are also interesting. It turned out that the genetics identified the sampled animal as Chamaeleo gracilis. However, the specimen itself was not examined by the researchers. It could be a Chamaeleo gracilis misclassified by its appearance. In this case, the specimens used for the species description in 2007 would have to be viewed and sampled again in order to obtain more information about the actual species’ status.

In the course of the genetic investigations, the researchers found out that the origin of the genus Chamaeleo probably lies in South Africa. Chamaeleo namaquensis, the only terrestrial chameleon of the genus Chamaeleo, split off from the other Chamaeleo species as early as 40 million years ago in the Eocene. This makes the Namaqua chameleon from the Namib Desert and Damaraland the “oldest” chameleon of the genus Chamaeleo. Chamaeleo anchietae followed about 29 million years ago.

Out of southern Africa: origins and cryptic speciation in Chamaeleo, the most widespread chameleon genus
Devon C. Main, Bettine Jansen van Vuuren, Colin R. Tilbury & Krystal A. Tolley Conceptualisation
Molecular Phylogenetics and Evolution, Volume 175
DOI: 10.1016/j.ympev.2022.107578