New data on the international trade in chameleons

New data on the international trade in chameleons

Science

Researchers from several universities recently analysed the international trade in chameleons. The focus was on Tanzania in East Africa. Tanzania is currently home to 41 of the 228 known species, making it the country with the second-highest number of chameleon species after Madagascar.

The study was based on the publicly accessible CITES trade database and the annual reports of the countries participating in the Washington Convention on International Trade in Endangered Species of Wild Fauna and Flora. Chameleons exported for scientific or non-commercial purposes were excluded. In addition, the most frequently clicked websites on the Internet in the form of English-language sales platforms, social media and forums were searched for sale and purchase adverts for chameleons using Google and “[species] for sale”. A total of 14 websites of commercial sellers, two online forums, two advertising websites, four social media sites and seven closed groups in social media were analysed. As a third pillar of the study, villagers in the Eastern Arc Mountains in Tanzania were interviewed using a questionnaire with eleven questions.

The general result of the study is that the international trade in chameleons fell rapidly between 2000 and 2019. At the same time, the number of chameleons bred in captivity increased. The number of “ranched” chameleons, i.e. chameleons bred on a farm in the country of origin for export, fell slightly. The largest export factor was commercial trade, with almost all species being exported directly from their countries of origin and not via other intermediaries in other countries. From 2000 to 2019, a total of 327,522 chameleons were legally traded. Only six countries accounted for 91% of exports: Tanzania, Madagascar, Mozambique, Uganda, Ghana and Cameroon. Tanzania was the country from which the most chameleons were traded, accounting for 34% of all exports. The country to which most chameleon exports went was the USA with 46%. The USA thus received almost half of all chameleons traded under CITES worldwide between 2000 and 2019. Other countries with relatively high numbers of chameleon imports were Japan (13%) and Germany (10%).

Six chameleon species from Tanzania were particularly sought after. Together they accounted for 85% of the trade in chameleons in the period mentioned. Kinyongia fischeri and Kinyongia tavetana were exported most frequently, followed by Trioceros werneri, Trioceros deremensis and Trioceros fuelleborni. Of the 42 species occurring in Tanzania, 35 were found for sale on online platforms and 29 were regularly on sales lists.

The on-site surveys in Tanzania revealed that only two out of three mountain ranges observed had participated in the trade in chameleons (East Usambara and Uluguru). As Tanzania has suspended its exports indefinitely since 2016, the majority of respondents stated that there is currently no longer any trade in chameleons. Interestingly, the villagers stated that they had collected 13 species for trade, but 7 of these species never appeared on the official exports for Tanzania. The answers to the question of how many chameleons of which species were traded also differed significantly from the official figures in the perception of the local population: While locals reported “thousands” of chameleons with one horn as supposedly collected annually, only very isolated ones of these were actually exported. There may also be a strong divergence here due to a lack of species differentiation.

Trade routes in Tanzania could be traced quite well through the interviews. In general, traders from Muheza and Morogoro came to the Usambaa and Uluguru mountains and gave the villagers a desired number of certain species (selected according to “one horn, two horns, three horns or giant”). A time limit was set, after which the traders returned and transported the collected chameleons to Dar es Salaam for export. One trader was questioned more intensively and stated that his father had already traded in chameleons. He had also never seen a collection permit, even though his clients always emphasised that they had one. The middlemen and collectors had no interest in what the collected chameleons were to be used for, only what was paid for them. Even a middleman only received 0.4 US dollars per chameleon.

Status and trends in the international wildlife trade in Chameleons with a focus on Tanzania
Maxim Conrad Isaac, Neil D. Burgess, Oliver J.S. Tallowin, Alyson T. Pavitt, Reuben M. J. Kadigi, Claire Ract
PLoS ONE 19(5), 2024.
DOI: 10.1371

Picture: Kinygonia tavetana, photographed by Elizabeth Dougherty, Creative Commons Attribution 4.0 International

Chameleons as prey of Compsophis infralineatus

Chameleons as prey of Compsophis infralineatus

Beobachtungen Science

Some interesting observations were recently made in central eastern Madagascar. Two snakes of the species Compsophis infralineatus were observed trying to devour chameleons as prey. Overall, not much is known about these snakes, but they were long thought to be primarily frog and egg eaters. An observation from 2018 already reports an attempt by another Compsophis species to eat a chameleon, which was regurgitated.

The current observations were made in the private rainforest of Vallombre Natiora near Mandraka. During night walks, an adult Compsophis infralineatus was discovered eating an adult Calumma gastrotaenia. The entire process of consumption was not observed, the snake had disappeared on return to the site, as had the chameleon. The authors assume that the chameleon was successfully devoured. On the same night, another snake of the same species was seen attempting to eat an adult Calumma crypticum. The chameleon was still alive and tried to free itself from the snake’s coils, but seemed unsuccessful first. Later, the same snake was seen again, hanging with its mouth in the back of the chameleon, which was apparently still alive but no with the snake wrapped around it. In the photo, it appears that the chameleon is still alive.

Predation on the chameleons Calummy crypticum Raxworthy and Nussbaum, 2006 and C. gastrotaenia (Boulenger, 1888) by the snake Compsophis infralineatus (Günther 1882) near Mandaka, Madagascar
Devin A. Edmonds and Samina S. Sam-Edmonds
Herpetology Notes (17), 2024: pp. 327-328
DOI:  not available

Picture: from the above-mentioned publication, CC BY-NC-ND 4.0

Sex chromosomes in chameleons

Sex chromosomes in chameleons

Science

Which sex chromosomes are present in chameleons has so far been studied rather sparsely. The Madagascan chameleon genus Furcifer is known to have Z and W chromosomes, although sometimes several Z chromosomes occur, so-called neo-sex chromosomes. Recently in the Czech Republic, scientists examined this deeper.

Blood and tissue samples were taken from 13 chameleons to isolate DNA. The animals sampled included one male and one female each of the species Brookesia therezieni, Calumma glawi, Calumma parsonii, Chamaeleo calyptratus, Furcifer campani, Furcifer labordi, Furcifer lateralis, Furcifer oustaleti, Furcifer pardalis, Furcifer rhinoceratus, Furcifer viridis, Kinyongia boehmei and Trioceros johnstoni. Only in Furcifer oustaleti were two females sampled. Subsequently, the Z1 chromosomes of the panther chameleons and the Z and W chromosomes were analysed by microdissection. Gene coverage analyses were performed for carpet and panther chameleons. In addition, qPCRs were performed to compare the homology of the Z chromosomes.

The results show that the morphology of the Z1 chromosomes of panther chameleons corresponds to the Z chromosome of the entire genus Furcifer. The Z1 chromosome of panther chameleons thus corresponds to the Z chromosome of Furcifer oustaleti. The Z2 chromosome of panther chameleons, on the other hand, is a neo-sex chromosome. Both the Z and W chromosomes in Furcifer oustaleti are probably pseudautosomal. 42 genes have been described as specific for the W chromosome.

A total of 16,947 genes were identified in Furcifer lateralis and 16,909 genes in Furcifer pardalis. The ratio of the number of genes between females and males is 0.35 and 0.65 for the two species. In panther and carpet chameleons, most of the genes on the W and Z chromosomes were found to be the same, with relatively few genes found only on the W chromosome. This finding is surprising, as the researchers had actually expected that the heterochromatic W in Furcifer species would have lost most of its genes compared to the Z chromosome.

The sex chromosomes of the genus Furcifer probably evolved at least 20 million years ago, which roughly corresponds to the time when the species Furcifer campani split off from the other Furcifer species.

Heteromorphic ZZ/ZW sex chromosomes sharing gene content with mammalian XX/XY are conserved in Madagascan chameleons of the genus Furcifer
Michail Rovatsos, Sofia Mazzoleni, Barbora Augstenová, Marie Altmanová, Petr Velenský, Frank Glaw, Antonio Sanchez, Lukáš Kratochvíl
Scientific Reports 14, 2024: 4898.
DOI: 10.1038/s41598-024-55431-9

Potential new distribution areas of the European chameleon

Potential new distribution areas of the European chameleon

Verbreitung Science

The European chameleon (Chamaeleo chameleon) was historically found in some small areas of the Mediterranean and Central Asia. Today, however, it is much more widespread. It is now assumed that the animals were brought to their new distribution areas by humans and were able to reproduce there due to the favourable climatic conditions. Scientists have now investigated where there are further suitable habitats for the European chameleon and how the existing populations could develop over the next 50 years.

The three subspecies studied were Chamaeleo chamaeleon chamaeleon, Chamaeleo chamaeleon musae and Chamaeleo chamaeleon reticrista. The former is known from the southern edge of Portgual and Spain as well as from southern Italy, Algeria, Egypt, Libya, Malta, Morocco, Tunisia, the western Sahara and Yemen. The second subspecies is currently found in Jordan, Israel and Egypt. The third subspecies occurs between Greece and Turkey, in Cyprus, Israel, Lebanon and Syria, but is actually native to northern Africa and the Middle East. It was probably introduced by people in southern Spain and Portgual, but is now considered a native species there.

For the study, the existing literature, sampling by the author himself, OpenStreetMaps and information from the Global Biodiversity Information Facility (GBIF) were used, statistically processed and analysed. Climate, topography, habitat of the sites and connections of existing populations were used to predict potentially suitable new habitats.

A total of 553 Chamaeleo chamaeleon findings were included in the study. 22% of the finds could be assigned to urban areas, 21% to scrubland and 18% to agricultural land. Most of the finds were made at altitudes of 0 to 100 metres above sea level. Not surprisingly, the areas currently colonised by Chamaeleo chamaeleon proved to be very suitable habitat. Potential well-suited new distribution areas in the future could be the Iberian Islands between Murcia and the Algarve in Portugal, Sicily, Calabria, Apulia and Sardinia in Italy, Morocco, Tunisia, Libya, the region between Israel and Lebanon in the Middle East, Cyprus and all coasts and islands of the Aegean Sea. Overall, a progressive increase in all existing habitats of the European chameleon is expected over the next 50 years. The only exceptions to this are probably some regions in Tunisia and Turkey. Further habitat losses are assumed on the Aegean coast in Turkey and Israel. In Spain and Portgual, the distribution area could shift westwards.

Habitat suitability and connectivity modelling predict a latitudinal-driven expansion in the Mediterranean basin for a historically introduced reptile
Davide Serva, Viviana Cittadino, Ilaria Bernabò, Maurizio Biondi, Mattia Iannella
European Journal of Wildlife Resarch 70 (27), 2024
DOI: 10.1007/s10344-024-01780-9

The two graphics are both from the publication mentioned.

New hope for Calumma tarzan

New hope for Calumma tarzan

Verbreitung Science

Calumma tarzan, the Tarzan chameleon, was only described in 2010. It was named after the place where it was found, Tarzanville, a small village in the Anosibe An’Ala region in the centre-east of Madagascar. Due to the previously assumed very small distribution area, the species was immediately classified as “critically endangered” on the IUCN Red List.

In 2020 and 2021, Malagasy scientists searched for the species in many other places in eastern Madagascar – and promptly found it, as a recent publication reports. They searched 46 transects, each one kilometre long, in 23 different forest fragments. A further 28 transects, each 200 metres long, were examined in order to assess the population density. Calumma tarzan was found in 14 of the 23 forest fragments analysed. None of these occurrences were previously known. The species occurred at altitudes of 604 to 1048 metres. Population density estimates varied greatly. In some areas there are only 25 chameleons per hectare, in others more than three times as many, namely 78.

Only a few of the forest fragments are currently protected. This study therefore emphasises how urgent it is to establish further protected areas in Madagascar’s eastern rainforests. This is the only way to save the Tarzan chameleon.

New distribution records and population density of the critically endangered Tarzan chameleon (Calumma tarzan), eastern Madagascar
Alain J.V. Rakotondrina, Raphali R. Andriantsimanarilafy, Hanta J. Razafimanahaka, Achille P. Raselimanana, Rikki Gumbs, Caleb Ofori-Boateng, Jody M. Taft, Fanomezana M. Ratsoavina
African Journal of Herpetology, 2024
DOI: 10.1080/21564574.2023.2291358

Mosquito bites may induce skin colour change

Mosquito bites may induce skin colour change

Tiermedizin Science

Sometimes science starts small: last year, someone posted a photo of a Calumma globifer with a mosquito sitting on it on the online platform iNaturalist. Right there you could see a black discoloration of the scales. I wonder if there was a connection?

A handful of curious people searched for more photos of mosquitoes on chameleons and found what they were looking for: On Facebook there were some of Veiled chameleons, on iNaturalist more of Furcifer minor and Furcifer nicosiai. However, there were also six observations of mosquitoes on chameleons that did not appear to have black spots.

To test the connection, scientists in Madagascar placed two Furcifer oustaleti and four carpet chameleons alone in an enclosure with 25 female Asian tiger mosquitoes (Aedes albopictus), which had not been fed for 24 hours beforehand. At the same time, all six chameleons were pricked in the skin with a needle to test whether this “trauma” would also trigger a color change in the skin. The results were surprising: in the four Furcifer lateralis, numerous black skin discolorations developed after mosquito bites, in the two Furcifer outaleti not a single one. The punctures with the needle remained without consequences in all six.

The authors of the recently published article propose three possible theories as to how the color change in the chameleon’s skin could come about: The mosquito saliva could contain a type of local anesthetic, nitric oxide or other proteins that cause the skin’s melanophores to become exclusively visible. Further research in this field would certainly be exciting!

Mosqito bite-induced color change in chameleon skin
Pablo Garcia, Raul E. Diaz Junior, Christopher V. Anderson, Tovo M. Andrianjafy, Len de Beer, Devin A. Edmonds, Ryan M. Carney
Herpetological Review 54(3), 2023, pp.353-358

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

What influences the rediscovery of lost species?

What influences the rediscovery of lost species?

Science

Throughout history, there have always been species that have been described once and then never seen again. There are also such cases among chameleons. Only a few years ago, the chameleon Furcifer voeltzkowi, which was thought to have been lost for almost 100 years, was rediscovered in western Madagascar. A recent publication by a large number of international authors now deals with the question of which factors influence rediscovery.

In 2023, the IUCN published a list of over 2,000 vertebrate species that had not been seen for more than ten years. Re:wild also published a list of 1008 lost species. Based on these lists and other literature, the scientists searched for species that had not been seen in the wild for more than ten years. In addition, there could not be any ex-situ populations (care in human hands outside the original occurrence). The result was a list of 1280 vertebrate species, which was then finalised with specialists in the respective fields. For example, species that are now considered extinct were excluded. This left 856 lost species, 42% of which were reptiles. The collected data was statistically analysed based on various factors.

Fewer reptiles were represented in the rediscoveries than mammals. Fewer reptile species were rediscovered than would have been statistically probable by chance. Reptiles also die out significantly faster than species are rediscovered. Overall, however, the rediscovery rate for reptiles is on the rise. Most rediscoveries have taken place in the tropics. Brazil and Ecuador are by far the countries with the most discoveries, closely followed by Australia, India and Madagascar. Surprisingly, a higher threat of habitat loss resulted in a higher rediscovery rate for reptiles.

Overall, there are several possible reasons why lost species have not yet been rediscovered. Firstly, there is a lack of data for several species – Brookesia lambertoni, which has not been seen in Madagascar since 1921, is mentioned here as an example. In the original description, its area of discovery is given as “Fito”. Fito is Malagasy for the number seven. Unfortunately, it is still not known what is meant by this name. There are many villages with the name, but it could also have meant a region, a river or a forest. It is also possible that the original description of the origin is due to a linguistic misunderstanding and that “Fito” does not exist as a place at all.

Furthermore, a lack of research capacity, especially in developing countries, also means a lower search intensity for lost species. In addition, many reptile species are rather inconspicuous and small. As a result, they are more difficult to advertise and attract little or no attention from potential sponsors. In addition, the habitat can also play a part in a species not being rediscovered. This is the case, for example, with very remote habitats or landscapes that are difficult to access, such as swamps.

What factors influence the rediscovery of lost tetrapod species?
Tim Lindken, Christopher V. Anderson, Daniel Ariano-Sánchez, Goni Barki, Christina Biggs, Philip Bowles, Ramamoorthi Chaitanya, Drew T. Cronin, Sonja C. Jähnig, Jonathan M. Jeschke, Rosalind J. Kennerley, Thomas E. Lacher Jr., Jennifer A. Luedtke, Chunlong Liu, Barney Long, David Mallon, Gabriel M. Martin, Shai Meiri, Stesha A.. Pasachnik, Victor Hugo Reynoso, Craig B. Stanford, P. J. Stephenson, Krystal A. Tolley, Omar Torres-Carvajal, David L. Waldien, John C.Z. Woinarksi, Thomas Evans
Global Change Biology 30, 2024, pp. 1-18.
DOI:  10.1111/gcb.17107

Photo: Furcifer voeltzkowi in Mahajanga, photographed by Alex Laube

Chameleons in Bobaomby (Madagascar)

Chameleons in Bobaomby (Madagascar)

Verbreitung Science

The Bobaomby complex is located at the northernmost tip of Madagascar, north and west of the largest coastal town in the north, Antsiranana (Diego Suarez in French). It consists of dry forest at sea level up to a maximum of 200 metres above sea level as well as extensive savannahs on karst rock and various rock formations. The area has not been protected to date.

Scientists from Madagascar conducted reptile counts in the Bobaomby complex in 2018. The counts were carried out in February and March, i.e. during the rainy season. Five different locations were analysed: Beantely, Antsisikala and Ambanililabe as examples of varying degrees of degraded dry forest, Anjiabe for its intact dry forest and Ampombofofo with relatively intact forest. To find animals, the visual survey was used on 25 days during the day and at night in selected transects, sometimes specifically in suitable habitats such as leaf axils or under dead tree trunks, and pitfall traps along erected fences were also used.

A total of 42 reptile species have been recorded. All of them, except one gecko species, originally only occur on Madagascar, while two other gecko species are now also found on neighbouring islands. There is a small novelty among the chameleons: the leaf chameleon Brookesia ebenaui was recorded for the first time in Bobaomby, more precisely in Beantely. Brookesia stumpffi and Furcifer petteri were found in Beantely, Anjiabe and Ampombofofo. Furcifer pardalis and Furcifer oustaleti occurred as expected throughout the whole Bobaomby complex.

The authors suggest that the Bobaomby complex – especially the three forests where most of the reptiles were found – should be protected to preserve the local herpetofauna.

Overview of reptile diversity from Bobaomby complex, northern tip of Madagascar
Randriamialisoa, Raphali R. Andriantsimanarilafy, Alain J. Rakotondrina, Josué A. Rakotoarisoa, Nasaina T. Ranaivoson, Jeanneney Rabearivony, Achille P. Raselimanana
Animals 13: 3396, 2023
DOI:  10.3390/ani13213396

Photo: Furcifer petteri, male, in the north of Madagascar, photographed by Alex Laube

The Indian Chameleon in Solapur (India)

The Indian Chameleon in Solapur (India)

Verbreitung Science

It has long been known that the Indian chameleon occurs in Maharashtra. A recently published survey study has even found evidence of it in an area near Solapur that is covered only with grass and bushes.

The area studied is a 15 km² area of semi-arid grassland around a site earmarked for an airport at an altitude of 450 to 500 metres. The nearest village is Boramani, a small town just outside the city of Solapur in the state of Maharashtra in western India. For one year, about half of the grassland was surveyed four times a month for the presence of reptiles. Squares of 50 metres x 50 metres were laid out, each at least 300 metres apart. Each observation period consisted of five hours and only observations with the naked eye.

During the study period, 888 individuals of 14 different reptile species were recorded. Of these, more than 300 were Sitana laticeps, a fan-throated lizard. Among the species found were two Chamaeleo zeylanicus. The activity of the lizards increased from March, stabilised during the monsoon season in June-July and then declined again from August.

The authors argue in favour of protecting the grassland area due to the existing biodiversity. This should prevent the construction of the airport and thus the disappearance of the habitat.

Ecology of lizards in an ecologically significant semi-arid grassland patch near Solapur, Maharashtra, India
Mahindrakar Yogesh Y., Waghmare Akshay M., Hippargi Rajshekhar V.
International Journal of Zoological Investigations 9 (2) 2023, pp. 210-223
DOI: 10.33745/ijzi.2023.v09i02.022