Chameleons in traditional medicine in Sierra Leone

Chameleons in traditional medicine in Sierra Leone

by Alex Negro Science

In Sierra Leone in West Africa, animal parts are still used in traditional medicine today. Two scientists from the University of Nala have now investigated exactly which ones and what they are used for.

The study was conducted in the chiefdoms of Kowa and Dasse between March and July 2023. Around 24,000 inhabitants live here, almost all of them farmers. Both areas are located in the Moyamba region in eastern Sierra Leone and are sparsely populated with the exception of four urban regions. The scientists interviewed 40 people and visited the patients they were treating. The interviewees included herbalists, traditional healers, fetish priests and obstetricians selected by the local population. People familiar with the area were asked about the fauna present. The animal parts used were photographed and sampled as far as possible.

As many as 17 of the interviewees had attended secondary school, while 17 others had received no schooling at all. All of them stated that they had learnt the healing methods used from their ancestors. 30 of the 40 interviewees made their living from traditional medicine and had been practising for around 30 years. A few even stated that they earned between $ 2120 and $ 4230 per year (the average for an employee in Sierra Leone is $ 2900 per year). Forty-five animal species were used for medicinal purposes, and 40 diseases were named as indications. The most frequently used animals, around a third, were reptiles, followed directly by amphibians, snails and mammals. Primates alone accounted for 10% of the animals used.

Chamaeleo gracilis was mentioned eighteen times during the interviews as a potential remedy. It is locally called ‘duqui’. Its skin, muscle parts and intestines are said to improve memory. It is also used for various mystical purposes. Most parts are eaten cooked.

Traditional medicines containing animal parts: Use in Kowa and Dasse chiefdoms, Southern Sierra Leone
Jonathan Johnny, Alhassan Bangura
Journal of Pharmacognosy and Phytochemistry 2024, 13(3): pp. 308-317
DOI: 10.22271/phyto.2024.v13.i3d.14972

Photo: Chamaeleo gracilis photographed by kogia, licence Creative Commons Attribution 4.0 International

How and when Veiled Chameleons show biotremors

How and when Veiled Chameleons show biotremors

by Alex Negro Science

Some chameleon species can vibrate like smartphones – most chameleon keepers know this. The best-known example of this ability is the Veiled Chameleon (Chamaeleo calyptratus). Two new articles by scientists from the USA now deal with what these vibrations are good for, how they occur, and how the Veiled Chameleon uses them in the first place.

Nine adult Veiled Chameleons (three females, six males) and six juvenile Veiled Chameleon (three females, three males) took part in the first experiments. Eleven of them were placed individually one after the other on a 77 cm long and 5 mm thick wooden stick. As soon as the chameleon sat in the middle, the wooden stick was subjected to vibrations of 25, 50, 150, 300, and 600 Hz. After each stimulus, a comparison was made to see whether the chameleon moved faster, slower, or the same as before. In order to motivate the young animals to move, a plant was placed near the end of the wooden stick. In addition, a small fan was used to imitate a light wind. For the second experiment, all 15 Veiled Chameleons were placed one after the other in a wooden box open at the top on a 122 cm long wooden stick. The animals were poked in the upper arm with a 27 G cannula. An acceleration sensor stuck to the helmet, or to the branch in the case of young animals, measured the reactions (vibrations) of the chameleons.

The results are exciting: Adult Veiled Chameleons reacted reliably to 50 and 150 Hz with “freezing”, i.e. complete immobility. Juveniles, on the other hand, reacted with this behaviour to other frequencies, namely 50 and 300 Hz. All adult Veiled Chameleons showed biotremors (vibrations). In the juveniles, the scientists could feel vibrations in all of them, but not all could be detected with the sensor. The vibrations were divided into two classes: “hoots” with an average of 7.5 dB and “mini-hoots” with -32.5 dB. The longer the larger vibrations lasted, the lower the frequency.

A second series of experiments used six adult Veiled Chameleons (four males, two females), four juvenile Veiled Chameleons, and one adult Chamaeleo gracilis. Two chameleons each were placed in a wooden box separated into two compartments by a plexiglass pane. Video recordings and accelerometers were used to measure their reactions to each other. Same-sex Veiled Chameleons, pairs of Veiled Chameleons, a Veiled Chameleon with a Chamaeleo gracilis and adult versus juvenile Veiled Chameleons were tested. The adult Veiled Chameleons showed vibrations in association with other adults in about 85% of the trials. The strength of the vibrations varied greatly from individual to individual. The clear trigger of the biotremors seemed to be visual contact with another chameleon. Threatening gestures and aggressive behaviour were more likely to cause vibrations. In the second series of experiments, a third variant of biotremors was discovered in addition to honking, rumbles.

Communication via biotremors in the Veiled Chameleon (Chamaeleo calyptratus): Part I – Biotremor production and response to substrate-borne vibrations
Kathryn L. Denny, Steve Huskey, Christopher V. Anderson, Michael E. Smith
Integrative and Comparative Biology, 2023
DOI: 10.1093/icb/icad085

Communication via biotremors in the Veiled Chameleon (Chamaeleo calyptratus): Part II – Social contexts
Kathryn L. Denny, Steve Huskey, Christopher V. Anderson, Michael E. Smith
Integrative and Comparative Biology, 2023
DOI: 10.1093/icb/icad084

Chamaeleo gracilis in Taï National Park (Côte d’Ivoire)

Chamaeleo gracilis in Taï National Park (Côte d’Ivoire)

by Alex Negro Science

Little is known about chameleons in the Republic of Côte d’Ivoire. Ivorian biologists have now confirmed the presence of various reptile species in one of the country’s national parks. For the first time, they have found Chamaeleo gracilis in Taï National Park, which matches its known range in West Africa.

Taï National Park is located in the southwest of Côte d’Ivoire in western Africa. The climate changes four times a year. From March to June there is a rainy season, in August it is dry, followed by a second rainy season in September and October and a second dry season from November to March. 40 areas, each 50 x 50 m in size, were surveyed. Of these, 18 were in primary forest (rainforest), seven in secondary vegetation with more shrubby growth, five in coffee or cocoa plantations, five in rubber tree plantations and five in rice fields. On each of 40 days, three researchers were in the demarcated areas for more than eight hours and visually scanned the surroundings for reptiles.

Chamaeleo gracilis was the only reptile observed exclusively in the rainforest. As is often the case with chameleons, a female was discovered laying eggs on the ground. The species was not found in secondary vegetation or agricultural landscapes.

First record of seven species of lizards in Taï National Park (South West, Côte d’Ivoire)
Kouadio Atta Léonard, Assemian N’guessan Emmanuel, Goly N’guessan Simplice, Keita Gaoussou, Tiédoué Manouhin Roland
International Journal of Zoological and Entomological Letters 2022, 2(2): 36-41
DOI: not available

Fieldguide to the Chameleons in Uganda

Fieldguide to the Chameleons in Uganda

by Alex Negro 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

by Alex Negro 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