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

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

Lecture in Hamburg about Madagascar

Lecture in Hamburg about Madagascar

Live lectures Reiseberichte

Together with Jutta Dwinger, AG member Lars Dwinger will be giving a presentation full of pictures in Schleswig-Holstein on Friday, 15th September 2022. Last year, the two travelled to the north of Madagascar, which is known for its extreme biodiversity.

The journey begins in the Marojejy National Park, which stretches across the gorges and steep slopes of the mountain range of the same name. There you can see extremely rarely photographed chameleons, but also a great variety of frogs, snakes and geckos. Afterwards, the journey led via the east coast towns of Sambava and Vohémar to the dry forest of Daraina. The next stop was the world-famous Tsingys in Ankarana National Park. Even in these two dry forests, there is a lot of small and big life. The final stop was camping in the middle of a chameleon paradise: The Montagne d’Ambre in the far north of Madagascar. Between tiny earth chameleons that just fit on the tip of a finger and the gentle giants of the rainforest, the two Hamburgers encounter many fascinating creatures on this trip.

Lars und Jutta Dwinger  Foray through four national parks in the north of Madagascar
Terrarien-Freunde-Hamburg e.V.
Vereinsheim des SC Condor
Berner Heerweg 188
22159 Hamburg
Start of the presentation at 6 p.m.

Picture: Brookesia betschi in Marojejy, photographed by Jutta Dwinger

Chameleons in mythology

Chameleons in mythology

General topics Newspaper articles

With its independently moving eyes, shooting tongue and ability to change colour, the chameleon was already the subject of superstition and myths in ancient times – and has remained so in many places to this day. An article now published by Prof. Dr. Wolfgang Böhme and natural historian Thore Koppetsch deals with precisely this topic.

The content ranges from the so-called Brooklyn Papyrus, which described a still unexplained “colour-changing” creature of antiquity, to bizarre events involving mother’s milk and chameleons in the Gambia of our time. Probably the oldest written record of a chameleon comes from Greece, from Aristotle himself, who lived from 384 to 322 BC. The term chameleon itself probably goes back to the Greek: chamai and leon were put together to form “earth lion”. However, this interpretation of the origin of the word is not entirely undisputed. The article also deals with superstitions on the island of Samos, in Morocco, Tunisia, Togo, Benin, Cameroon and Madagascar, and the use of chameleons for pseudo-medicine and occultism.

Chamäleons in der Mythologie der Völker
Wolfgang Böhme, Thore Koppetsch
Koenigiana 17, 2023, pp. 39-50
DOI: nicht vorhanden

Unknown chameleon discovered in Ivohiboro forest (Madagascar)

Unknown chameleon discovered in Ivohiboro forest (Madagascar)

Verbreitung Science

There are still almost unexplored areas on Madagascar today. The Ivohiboro rainforest is located in the southeast of the island in the protected area of the same name, southwest of the southernmost foothills of the Andringitra Mountains. The forest itself is about 8.58 km² in size and thus only occupies a small part of the protected area. It is surrounded by savannahs and spans altitudes from 650 to 1460 m above sea level. The protected area is currently managed by local organisations and Madagascar’s Ministry of Environment. The last expedition to explore the Ivohiboro forest took place in 1924. Since 2016, researchers from the USA and Great Britain have now undertaken six expeditions to the small forest to study the biodiversity of plants, birds, mammals, reptiles, and amphibians there in more detail.

To detect reptiles and amphibians, the forest was divided into nine transects of about 200 x 20 m, each more than 200 m apart. The transects were searched for several days and nights. All animals found were documented and, if possible, identified down to genus or species level.

As a result, the scientists were able to identify 107 species of vertebrates and 219 plants. This enormous diversity of species underlines the importance of preserving the forest in terms of species conservation and indicates a well-functioning ecosystem. Among the species found were two chameleons: a Palleon species and a small Calumma. Unfortunately, the publication does not provide any further information on the former. The small Calumma had a conspicuous blue coloured rostral appendage, as it is found in Calumma linotum or Calumma boettgeri in the far north of Madagascar. As genetic studies are still lacking, it is unclear whether these chameleons are an extremely wide range extension – Ivohiboro lies about 1000 km south of the ranges of Calumma boettgeri and Calumma linotum – or whether it is perhaps even a new, as yet undescribed species.

A surprising haven: The biodiversity of an old-growth forest amidst a scorched landscape in Madagascar
Beatriz Otero Jimenez, Ren Montaño, Ryan S. Rothman, Rachel C. Williams, Patricia C. Wright
Conservation Science and Practice, 2023
DOI: 10.1111/csp2.12993

Chameleons in the Montagne des Français (Madagascar)

Chameleons in the Montagne des Français (Madagascar)

Verbreitung Science

The Montagne des Français is a limestone massif with dry forest in northern Madagascar. It reaches up to 425 m above sea level and is within sight of the largest coastal town in the north, Antsiranana (French Diego Suarez). It has been a protected area since 2007. Scientists from Madagascar and the USA conducted counts of reptiles and amphibians in the Montagne des Français in 2014 and 2020.

Counts were made in January and May, i.e. during and at the end of the rainy season. In 2014, the focus was on the region around Andavakoera, while in 2020 it was on Sahabedara, Ampitiliantsambo, and Andavakoera. In order to find animals, the search was conducted during the day and at night along predefined paths, partly in suitable habitats, and partly in pitfall pits.

A total of 20 amphibian and 50 reptile species were recorded. Four new amphibians and one reptile were found for the first time in the Montagne des Français. The snake Langaha pseudoalluaudi was discovered again for the first time since 2007. Among the chameleons, there were minor new discoveries. Brookesia stumpffi could only be found in 2014, but no longer in 2020 – however, due to the relatively wide distribution of the species, this should not be a problem for the entire population. Brookesia tristis, one of the smallest chameleons in the world, was also only seen in 2014. Here, the body size, which makes it very difficult to find, and the time of year (May is relatively late for this species) could play a role. Brookesia ebenaui was detected in Andavakoera in 2014 and in Sahabedara in 2020. The two tree dwellers Furcifer oustaleti and Furcifer pardalis were found in both years in Andavakoera and Ampitiliantsambo. Furcifer petteri, on the other hand, was present at all the sites surveyed in both years.

Amphibians and reptiles of the “Montagne des Français”: Update of the distribution and regional endemicity
Herizo Oninjatovo Radonirina, Bernard Randriamahatantsoa, Rabibisoa Harinelina Christian Nirhy, Christopher J. Raxworthy
Preprint
DOI: 10.20944/preprints202306.1499.v1

Photo: Furcifer petteri on Madagascar, photographed by A. Laube

Habitat of Furcifer labordi in Andranomena (Madagascar)

Habitat of Furcifer labordi in Andranomena (Madagascar)

Science

Labordes’ chameleon (Furcifer labordi) has been known for some years as the world’s shortest-lived chameleon. Three scientists from Madagascar have now studied a previously relatively unexplored habitat of the species. The study was conducted in the Andranomena Special Reserve, located about 30 km north of the coastal town of Morondava in western Madagascar. The special reserve has a regrowth part as well as a relatively intact part of dry forest, which lies at altitudes ranging from sea level to 250 metres.

To estimate the population density of Furcifer labordi, the forest was divided into three transects each 150 m wide. At night, the chameleons were searched for with a torch and colour-marked with nail polish. The next day, a 5 x 5 m plot was marked around each site and at least 5 m away along the transect line. In all plots, the canopy cover was counted in percent, the thickness of the foliage layer on the ground and ground-covering plants in centimetres, the number of shrubs up to 1 m, the number of trees over 1 m and the number of felled and burnt trees. Five days after the first count, chameleons were again searched for and counted at night. In addition, insects were caught, counted and identified using light traps. Furthermore, raptor observations (Centropus toulou, Falco newtoni, Buteo brachyperus, Corvus albus and Accipiter francesii) were counted every 200 m along a 1400 m transect. Other predators such as snakes (Madagascarophis colubrinus, Leiohterodon modestus, Mimophis mahfalensis, Dromicodryas bernieri) were also counted by observation. Climatic data from the urban area of Morondava were recorded.

Statistical analyses showed that more Furcifer labordi were found in forest sections where the canopy was denser and the foliage layer on the ground was thicker, and where there were more trees overall. In the forest sections where no chameleons were found at all, significantly more felled trees were counted. As was to be expected, considerably fewer Furcifer labordi were found in the dry season than during the rainy season. Ten different families of insects were found, the most common being Homoptera (mainly cicadas), Coeloptera (beetles), Dermaptera (earwigs), and Lepidoptera (butterflies). Insect availability seemed consistent from February to May. More snakes were counted in February than in March, and the number of birds of prey did not differ throughout the observation period.

The authors consider whether the differences between the microhabitats preferred by Furcifer labordi and non-habitats could have an impact on the longevity of the species. Unfortunately, causality was not proven.

Variation longitudinale de longévité de Furcifer labordi et analyse de facteurs à l’origine de sa longue durée de vie dans la reserve spéciale d’Andranomena-Morondava, Madagascar
Ahy Nirindrainiarivony Philibertin Honoré Djadagna, Achille Philippe Raselimanana, Lily-Arison René de Roland
ESI Preprints 18, 2023
DOI: 10.19044/esipreprint.6.2023.p700

YouTube live about Malagasy chameleons

YouTube live about Malagasy chameleons

Live Stream Live lectures

On Saturday, 10 June 2023, there will be a live discussion on YouTube with the herpetologist Mark D. Scherz and Bill Strand from the Chameleon Academy in the USA. The topic will be the Malagasy chameleon Calumma brevicorne and its numerous relatives, some of which are extremely similar in appearance. Taxonomically, many chameleons of the brevicorne clade are not yet classifiable – possibly some undescribed new species are hiding among them? There will be an opportunity to ask questions about the topic live in the chat throughout the hour. This should be a very exciting talk round!

Chameleons & Coffee: Confusing Madagascar chameleons
Chameleon Academy YouTube Channel
Starting at 9.00 p.m.

Panther chameleons in Madagascar

Panther chameleons in Madagascar

General topics Verbreitung Newspaper articles

In the bi-monthly magazine of the DGHT e.V., the Elaphe, a nice article on the panther chameleons of Madagascar has been published. It was written by two members of the AG Chamäleons who regularly travel to the island.

The article describes in words and pictures the distribution area of the panther chameleons on Madagascar, which extends over the northern half of the island, more precisely from a few kilometres south of the village of Ankaramibe in the northwest to the north of Madagascar and down the east coast to about 90 km south of the port city of Toamasina. The chameleons are found mainly in secondary vegetation in open landscapes, but also in cocoa plantations, overgrown gardens and rainforests.

The life cycle of the panther chameleons in Madagascar is mainly determined by the rainy season between November and March. The chameleons mate during this time. After 30 to 40 days, the females lay between 11 and 35 eggs in a nest they have dug themselves. The young hatch only in the next rainy season.

The article goes into particular detail about the different local forms, the different colour appearance of the male panther chameleons depending on the location. The authors currently count more than 30 different local forms on Madagascar, which are separated from each other by natural barriers such as rivers. There are probably many more, but not all of them have been discovered yet.

Pantherchamäleons (Furcifer pardalis) – Meister der Farben
Thorsten Negro and Alexandra Laube
Elaphe 3, 2023, pp. 12-25

Photo: Panther chameleon of the local form Ambanja on Madagascar, photographed by Thorsten Negro.

Chameleons at different altitudes of the Amber Mountain (Madagascar)

Chameleons at different altitudes of the Amber Mountain (Madagascar)

Science

International scientists have intensively studied the different altitudes of the Amber Mountain and the amphibians and reptiles found there. The Amber Mountain (French Montagne d’Ambre) is a former volcanic massif in northern Madagascar. The mountain, which is up to 1475 m high, is mainly covered by rainforest, which belongs to the national park of the same name. To the north of the mountain is a dry forest that belongs to the Forêt d’Ambre Special Reserve. The north-western flank of the mountain has not yet been protected.

In the present work, amphibians and reptiles were observed and sampled over 12 km between 700 and 1470 metres altitude. The western slope of the Montagne d’Ambre at altitudes between 770 and 1290 m was also included in the study for the first time. In addition, animals were sampled in the Forêt d’Ambre from 470 m altitude. All animals found were measured. Cheek swabs, scales as well as live animals that had been euthanised were collected and genetically analysed. A total of 2631 observations of 34 species of amphibians and 48 species of reptiles were made. As expected, different animals occurred at different altitudes. The species richness of the Montagne d’Ambre was greatest at around 1000 m a.s.l. with 41 different species. Above 1100 m, about one third of the species found were locally endemic.

Two genetic clusters of the earth chameleon Brookesia tuberculata have been identified. Group 1 lives on the eastern flank of the Montagne d’Ambre at altitudes of 887 to 1170 m, group 2 at 1260 to 1455 m on the eastern flank and at 956 to 1150 m on the western slope of the Montagne d’Ambre. Group 1 showed a particularly high number of mitochondrial haplotypes, while group 2 had only one haplotype. The scientists assume that due to their small body size and high site fidelity, the species tends to form isolated groups rather than tree-inhabiting chameleons, which can overcome natural barriers more easily and thus move within a much larger environmental radius.

In Calumma linotum, the genetic differences between three groups at different altitudes were rather small. The measurement data of various body dimensions also showed no clear trend for this species at the different altitudes. Although Calumma linotum appeared to be slightly smaller at lower altitudes, this could have been due to subadult individuals misidentified as females. For Calumma amber and Calumma ambreense, body size decreased the higher the chameleons were found in the Montagne d’Ambre. This may be related to the cooler temperatures at higher altitudes, which contribute to slower growth. But it could also be that more younger animals were simply measured.

The study reveals interesting adaptations of different chameleon species to the altitudinal differences of the Montagne d’Ambre. It is possible that these are already the first indications of an early stage of speciation. The work also illustrates how important the different altitudinal levels are for species diversity.

Repeated divergence of amphibians and reptiles across an elevational gradient in northern Madagascar
Mark D. Scherz, Robin Schmidt, Jason L. Brown, Julian Glos, Ella Z. Lattenkamp, Zafimahery Rakotomalala, Andolalao Rakotoarison, Ricky T. Rakotonindrina, Onja Randriamalala, Achille P. Raselimanana, Safidy M. Rasolonjatovo, Fanomezana M. Ratsoavina, Jary H. Razafindraibe, Frank Glaw, Miguel Vences
Ecology and Evolution 13 (3)
DOI: 10.1002/ece3.9914