Chameleons in St. Luce (Madagascar)

Chameleons in St. Luce (Madagascar)

by Alex Negro Verbreitung Science

The St. Luce reserve is located in the south-east of Madagascar, just 34 km north of the city of Tolagnaro (Fort Dauphin). The protected area includes beaches and rocky cliffs on the coast of the Indian Ocean, lowland rainforest, marshland, savannah-like plains, rivers and lagoons. The remaining rainforest is broken up into many small fragments. There is also a very large rare earth mining project in the area. 12 of the 17 forest fragments of St. Luce are affected by the mining work. A group of scientists has now studied the herpetofauna of the area in more detail.

Over a period of two years, reptiles and amphibians were searched for and captured in St. Luce. The searches were carried out with the naked eye along existing transects. In addition, ground traps were used for two weeks along four 100 m long lines. Five artificial shelters and five corrugated sheets were laid out at a total of 12 locations to check for animals after a certain period of time. Samples of tail tips and toes were taken and measurements taken, after which the animals were released back to their original locations. The species were identified by genetic analysis.

Of 17 rainforest fragments in St. Luce, the scientists found only one intact and another intact but heavily fragmented. All other forest fragments were found with clear signs of habitat destruction. A total of 22 amphibian and 54 reptile species were found. Four species of chameleons were among the reptiles: Palleon sp. aff. Nasus, Calumma tjiasmantoi, Furcifer major and Furcifer verrucosus. All four chameleon species occurred exclusively in the remaining intact or intact areas of the Angalavinaky, Ambandrika and Andranangy/Amboronteny/Agnalaro forests. In the forests already destroyed by the mine, no chameleons were found at all. Of the 76 amphibian and reptile species found, 13 were candidate species, which are presumably undescribed new species.

The authors point out that, according to the present study, the diversity of the herpetofauna in St. Luce is significantly greater than previously assumed. They suggest that several forest fragments should be included in the “Mining Avoidance Zones”, i.e. areas where rare earths should not be searched for, and that the protection status should be increased.

A littoral treasure trove: a comprehensive assessment of the herpetofauna of Sainte Luce, southeastern Madagascar
Sam Hyde Roberts, Marco Sannolo, Hoby Tsimijaly Longosoa, Ryan Clark, Leo Jhaveri, Gonçalo M. Rosa, Walter Cocca, Franco Andreone, Angelica Crottini
Systematics and Biodiversity 23(1): 2513472
DOI: 10.1080/14772000.2025.2513472

Photos: Chameleons found in St. Luce from the aforementioned publication

Frugivory in Furcifer oustaleti

Frugivory in Furcifer oustaleti

by Alex Negro Beobachtungen Science

Frugivory, the eating of fruit, is only known from a few chameleon species. These are mainly isolated observations. Japanese scientists have recently investigated the extent to which fruit-eating chameleons could contribute to the spread of plant seeds.

The study was carried out in the Ankarafantsika National Park in western Madagascar. Three species of reptiles in Madagascar were observed during two rainy seasons and their droppings were examined: The Madagascar giant chameleon Furcifer oustaleti, the Madagascar iguana Oplurus cuvieri and the plated lizard Zonosaurus laticaudatus. The reptiles were observed during the day and filmed or photographed while feeding on fruit and then captured. Chameleons were mainly caught at night. Fruits with seeds were collected for identification from plants on which reptiles of the three species mentioned had been feeding. All captured reptiles were kept in net containers for 6 days until faeces were deposited. The animals were then microchipped and released back into their habitats. The scientists then attempted to sow plant seeds obtained from the animals’ excrement.

A total of 89 chameleons, 254 Madagascar iguanas and 38 shield lizards were captured for the study. 24.7% of the Furcifer oustaleti sampled had plant seeds in their feces, compared to 20.1% of the iguanas and 15.8% of the tortoiseshell lizards. The observations showed that the chameleons and the plated lizards ate fruit from at least eight different plants, while the iguanas ate from as many as 18 different plant species. Some of the plant seeds obtained from the feces had germination rates of over 50%.

During the observation period in Ankarafantsika, Furcifer oustaleti only ate red, black or brown fruits with a maximum diameter of one centimeter. Green or larger fruits were always left on the plants. The fruits were usually first tapped with the tongue before they were actually eaten. Sometimes the fruits were also shot with the tongue. Fruits of Grangeria porosa, Terminalia boivinii, Trilepisium madagascariense, Antidesma madagascariense, Bridelia perviellana, Phyllanthus casticum, Chassalia princei and Doratoxylon chouxii were ingested by Furcifer oustaleti. Fruits were recorded from both sexes of chameleons and regardless of body size in each of the observation months.

The authors conclude that all three reptile species could contribute to the spread of plants in their habitat. Until now, the brown maki (Eulemur fulvus) in Ankarafantsika was primarily thought to be a seed disperser. Now the considerations should probably be extended to reptiles and their role in the forest ecosystem – even if the proportion of seeds in their droppings is significantly lower than that of lemurs.

Frugivory by three species of lizards in Madagascar: Implication for their ecological roles as seed disperser
Ryobu Fukuyama, Wataru Noyori, Shuichiro Tagane, Shouta Iyoda, Hiroki Sato
Biotropica 57(4): e70052
DOI: 10.1111/btp.70052

Photo: Furcifer oustaleti eating fruit, image from the above-mentioned publication

First vertebrate with annual allochrony: Chamaeleo chamaeleon musae

First vertebrate with annual allochrony: Chamaeleo chamaeleon musae

by Alex Negro Science

Allochrony describes the phenomenon that two or more populations of a species have different reproductive cycles over time, even though they occur in the same habitat. In so-called annual allochrony, the populations reproduce at different times of the year. Allochrony is known from many different species, such as insects and corals, which reproduce at different times of the day. Annual allochrony, on the other hand, is extremely rare and has never been demonstrated in vertebrates. Two scientists from Israel have now discovered this phenomenon in chameleons for the first time.

Between 2009 and 2021, they studied the Chamaeleo chamaeleon musae populations in the Holot Mash’abim Nature Reserve in Israel on two nights per month. The reserve is located in the northwestern part of the Negev desert. During the study, the chameleons were searched for from a slow-moving car with flashlights along a 4 km long path. Animals found were measured, sexed, location recorded and claws clipped in a specific sequence for identification. All animals were released at their location within less than 20 minutes. In order to estimate the age of the animals, the time periods between the recovery of previously marked animals were used, as well as an algorithm developed using XGBoost. The chameleons could thus be assigned to the age classes < 1 year, 1-2 years and > 2 years. All data was statistically analyzed.

The astonishing results show that Chamaeleo chamaeleon musae probably occurs in two populations in the Negev desert, separated by annual allochrony. In odd-numbered years, one population of chameleons hatches in September. These animals survive until about November of the following year. In even-numbered years, the second population of chameleons hatches, whose animals also live until November of the following year. The lifespans of the two populations only overlap for a short period of time, when one population is hatching and the already adult animals of the other population are laying eggs. The reproductive Chamaeleo chamaeleon musae of both populations therefore do not overlap or only very rarely due to very few, longer-lived individuals.

The scientists were able to find a total of 1289 chameleons < 1 year old, 231 aged 1 to 2 years and 27 chameleons > 2 years old. Of these, 713 Chamaeleo chamaeleon musae had already been caught for the first time as juveniles, so that their age could be estimated very well. Only 9 of these were rediscovered between 1 and 2 years of age. The survival rate of the hatchlings until their first breeding season was extremely low. In odd-numbered years it was 1%, in even-numbered years 2.5%. Even fewer chameleons survived the first year, at 0.46% and 1.3%. Both populations of Chamaeleo chamaeleon musae were highest in the first and second month of hatching and then declined rapidly. Male chameleons were slightly less likely to survive the first breeding season than females, but overall survival rates were similar for both sexes. In each year of observation, the first hatchlings emerged between mid-September and mid-October, at the end of the hot season. During the cooler and wetter season from December to March, significantly fewer chameleons, most of them juveniles, were found.

This very exciting study naturally raises many more questions. There are several short-lived chameleons, but the entire life cycle of only a few, such as Furcifer labordi, is even known or has been studied. It is possible that there are even more vertebrates with annual allochrony among the chameleons – this still needs to be researched!

First evidence of yearly allochrony in a terrestrial vertebrate: A case study of an annual chameleon
Liran Sagi, Amos Bouskila
Ecology 106(6), 2025: e70144
DOI: 10.1002/ecy.70144

Picture: Chamaeleo chamaeleon, photographed by Markus Grimm

Avian predators of the Indian Chameleon

Avian predators of the Indian Chameleon

by Alex Negro Beobachtungen Science

This week, a review paper was published in which an Indian biologist summarizes a series of observations in which birds have attacked chameleons in Sri Lanka and India. These are exclusively observations with Chamaeleo zeylanicus, the Indian chameleon, as prey.

A total of seven birds have already been observed either attacking or eating Chamaeleo zeylanicus between 2012 and 2023. In Bhadreshwar on the western edge of India, a greater coucal (Centropus sinensis) was observed preying on a chameleon. In the Janbughoda Wildlife Sanctuary in eastern India, it was a rufous treepie (Dendrocitta vagabunda) that flew away with a chameleon in its beak and was then photographed eating it. In the Kolli Hills in southern India, a crested serpent eagle (Spilornis cheela) was observed eating an Indian chameleon. Three other crested serpent eagles were seen hunting in Wilpattu National Park in Sri Lanka. Another observation in the same national park shows the Malabar pied hornbill (Anthracoceros coronatus) as a predator of chameleons.

Avian predators of the Indian Chameleon Chamaeleo zeylanicus
Raju Vyas
Biodiversity Observations 15, 2025: 96-98
DOI: 10.15641/bo.152

Photo: Rufous treepie eating an Indian chameleon, the photo was taken from the open source publication mentioned above

Eagle owl captures chameleon

Eagle owl captures chameleon

by Alex Negro Beobachtungen Science

The eagle owl (Bubo bubo) is the largest native owl in Europe and has a large range that extends as far as Greece. It is not only very adaptable in terms of the habitat it uses, but also in terms of its prey. Known and common prey in the Mediterranean region include small to medium-sized mammals and other smaller birds. Ampihibians, reptiles, fish and invertebrates such as insects are also preyed upon, but have always been considered more of a stopgap, especially in areas of Greece where there is a lack of larger prey.

Greek authors recently made a very special observation on the prey spectrum of the owl species in the area around Pylos in the western Peloponnese. In July 2024, the authors observed an eagle owl hunting in the early morning. To their surprise, it preyed on a Chamaeleo africanus. This is the first published observation of an eagle owl preying on a chameleon. Further research on this would be desirable, as there is a general lack of data on the prey spectrum of eagle owls in the Peloponnese.

An exceptionally rare predation on a chameleon species (Squamata: Chamaeleonidae) by a Eurasian Eagle-Owl (Aves: Strigidae)
Apostolos Christopoulos, Luca Cornacchia, Christos Kotselis, Yiannis G. Zevgolis
Diversity 17, 2025: 333
DOI: 10.3390/d17050333

Photo: from the publication mentioned

Madagascar giant chameleon eats carpet chameleon

Madagascar giant chameleon eats carpet chameleon

by Alex Negro Beobachtungen Science

Three authors report an interesting observation from the capital of Madagascar, Antananarivo. Near Akamasoa, they observed a male Furcifer oustaleti in the process of devouring another chameleon. The animal had not been observed hunting. The victim, presumably a carpet chameleon (Furcifer lateralis), was completely devoured within a few minutes.

The observation is one of a few exciting sightings of relatively large chameleons that at first glance appear to eat ‘too large’ prey. However, this does not seem to happen very often, as the few existing observations are spread over several decades. It is interesting that the new observation was made in the dry season, when the insect density is significantly lower compared to the rainy season.

Predation on Furcifer sp. by Oustalet’s Chameleon, Furcifer oustaleti (Mocquard, 1894), in the Central Highlands of Madagascar
Angelinah René de Roland, Duvivier Razarazafy, Séraphin Fabrice
Herpetology Notes 18: 305-306.
DOI: not available

Photo: from the publication mentioned

Scientists discover second ‘super muscle’ in chameleon tongues

Scientists discover second ‘super muscle’ in chameleon tongues

by Alex Negro Science

Scientists have been investigating how chameleons’ tongues can shoot out of their mouths to such an extreme length for as long as anyone can remember. US biologists have now been able to solve another piece of the chameleon tongue puzzle.

In the study, experiments were carried out on 15 Veiled chameleons (Chamaeleo calyptratus). All 15 animals were first anaesthetised using overdosed gas anaesthesia and then killed by decapitation. The four tongue muscles were then dissected out and clamped in measuring devices. The muscles were stimulated with an electric current and the passive/active forces and various muscle lengths were measured. A series of calculations were then carried out and muscles were examined histologically. In addition, embryos previously obtained from eggs were analysed immunohistochemically to determine whether the tongue muscles develop from the same or two different muscle systems.

The results of the study are very interesting and focus primarily on the so-called sarcomeres of the muscles. A sarcomere is the smallest contractile unit of the muscle – i.e. the part that is responsible for the expansion and contraction of the muscles. At both ends of each sarcomere are the so-called intermediate discs (German “Zwischenscheibe”), abbreviated as Z-discs. Transverse striated muscles, i.e. the muscles that move the arms, legs and trunk of a vertebrate, can shorten to about half their resting length. In chameleons, however, there is a very special type of muscle, the so-called supercontracting muscle. By definition, this is a striated muscle that is able to shorten to less than half its resting length. The rectractor of the tongue, the hyoglossus muscle, is just such a muscle. In this muscle, perforated Z-discs on the sarcomeres ensure that it can stretch far better than normal striated muscles.

In the present study, it was found that a second supercontracting muscle is involved in the tongue shot: the sternohyoid superficialis muscle. In its counterpart, the sternohyoid profundus muscle, surprisingly, no perforated Z-discs could be detected at the sarcomeres. However, its length-tension ratio corresponded to the two supercontracting tongue muscles. This could be compensated for by the very broad attachment of the muscle to the hyoid bone. During tongue shooting, these areas of the hyoid bone are rapidly rotated, which could mechanically alter the sarcomeres.

Using immunohistochemistry, the biologists were also able to show in chameleon embryos that the two muscles develop from different origins, which is consistent with the different sarcomeres. Both the hyoglossus muscle and the sternohyoid muscles form a muscular unit, with one of the muscles even extending to the sternum. This means that the maximum length of the chameleon tongue when shooting is not only made possible by the special properties of the tongue muscles, but also by the overall length of the muscular unit. No other vertebrate in the world has ever been found to have two supercontracting muscles.

Feats of supercontractile strength: functional convergence of supercontracting muscle properties among hyoid musculature in chameleons
Nikole G. Schneider, Nicholas A. Henchal, Raul E. Diaz Jr., Christopher V. Anderson
Proceedings B of Royal Society Publishing, 2025
DOI: 10.1098/rspb.2025.0078

Figure: Schematic representation of the tongue muscles and hyoid bone in the Veiled chameleon from the aforementioned publication

Furcifer verrucosus discovered in the stomach of a snake

Furcifer verrucosus discovered in the stomach of a snake

by Alex Negro Beobachtungen Science

Biologists from the University of Michigan (USA) recently made a curious discovery: they analysed a snake of the species Langaha madagascariensis that had been prepared 31 years ago using dissection and microCT. The specimen had been largely untouched in the Zoological Museum of the University of Michigan since 1994. The snake was originally collected by R.A. Nussbaum in the extreme south of Madagascar, not far from Tolagnaro. Little is known about the diet of the leaf-nosed snake, only anecdotal case reports are known. Chameleons have now been added to the list of potential prey: An adult Furcifer verrucosus was found in the stomach of the female leaf-nosed snake examined.

Natural history notes: Langaha madagascariensis (Malagasy leaf-nosed snake)
Andressa L. Viol, Hayley L. Crowell, Justin L. Lee, Tristan D. Schramer
Herpetological Review 55 (2), 2025: 223-226.
DOI: not available

Photo: Furcifer verrucosus, photographed by Nick Newberry, CC BY 4.0

Veiled chameleon distributed over 12 new counties in Florida (USA)

Veiled chameleon distributed over 12 new counties in Florida (USA)

by Alex Negro Verbreitung Science

Introduced Veiled chameleons (Chamaeleo calyptratus) have been living in Florida (USA) since at least 2002. The first wild Veiled chameleons were found in Collier County, two years later animals were observed in Fort Myers in Lee County. This was followed by findings in Hendry, Miamia-Dade, Broward, St. Lucie, Palm Beach, Monroe, Alachua and Hillsborough County. Now an author in the Herpetological Review reports on 12 further populations in Florida: in Brevard, Charlotte, De Soto, Glades, Indian River, Lake, Manatee, Osceola, Pinellas, Polk, Sarasota and Seminole County.

He used data from iNaturalist and EDDMapS. The author suspects that most of the new finds could be due to so-called chameleon ranching. Chameleons are deliberately released into other habitats in order to later collect and sell the resulting juveniles. But even without prior release, collecting (‘harvesting’) animals for sale has become a source of income in Florida, which has also led to the fact that distribution data on new populations is rarely published. It is now a common recreational activity in Florida to search for Veiled chameleons at night. There are even commercial operators offering guided tours.

One problem is increasingly the owners of private property who feel disturbed by ‘chameleon tourism’. The impact on native wildlife in the USA is still unclear. Theoretically, Veiled chameleons could eat smaller mammals or young birds, but there have been no reports of such incidents in Florida to date.

It seems increasingly unlikely that it will be possible to get rid of the introduced Veiled chameleons. A one-year trial in Lake Worth Beach (Palm Beach) resulted in 1043 chameleons being caught during 71 collection campaigns, but not in the elimination of the population living there.

New County Records for the Veiled Chameleon (Chamaeleo calyptratus) in Florida, USA
Kevin M. Enge
Herpetological Review 55 (2), 2025: 223-226.
DOI: not available

Photo: Chamaeleo calyptratus, found and photographed in Fort Myers (USA) by Andrew Durso, CC-BY

New genomes of six chameleon species from Ethiopia

New genomes of six chameleon species from Ethiopia

by Alex Negro Science

A very brief publication by three scientists deals with the genome sequences of reptiles. Wild reptiles from a total of 101 different species were sampled in Ethiopia, Guyana, Mexico and the USA. Unfortunately, the authors do not state exactly how the sampling was carried out and whether whole animals or only tissue samples were taken. DNA was extracted using the Qiagen DNAeasy Kit and Illumina TruSeq kits were used for sequencing.

All genomes were deposited at Genbank. Genomes of one Chamaeleo dilepis (JBHLFC00000000000), one Chamaeleo laevigatus (JBIELG00000000000), one Trioceros affinis (JBHUPM00000000000), one Trioceros balebicornutus (JBHZFU00000000000), one Trioceros harennae (JBHRFO00000000000) and one Chamaeleo gracilis (JBINKK00000000000) were deposited. Several entries of these species already existed in GenBank.

The complete genome sequences of 101 species of reptiles
Timothy J. Colston, Stacy Pirro, R. Alexander Pyron
Biodiversity Genomes, 2025
DOI: 10.56179/001c.129597

Picture: Chamaeleo laevigatus, photographed by John Lyakurwa, Creative Commons Attribution 4.0 International