Concerning Florida’s introduced panther chameleons

Concerning Florida’s introduced panther chameleons

by Alex Laube Verbreitung Science

The “Sunshine State” Florida in the USA has the largest number of non-native species of reptiles in the world because of its warm climate. The panther chameleon (Furcifer pardalis) is one of the invasive species, i.e. those that do not actually belong in Florida but are now reproducing there. A study has now investigated the question of what the human inhabitants of Florida actually think of the chameleons.

It has been discussed for a long time whether panther chameleons belong to the species that were deliberately released for the purpose of “ranching”, i.e. to collect the offspring of the released chameleons for sale. That private individuals collect panther chameleons is not in dispute. According to the authors, ranching populations in Florida are mostly kept secret. They became aware of a small population in Orange County via social media in 2019. They then searched for the animals at night with torches and actually found 26 panther chameleons during several walks. They encountered private individuals on several occasions who were also looking for chameleons.

In 2020, questionnaires were distributed in person and via flyers with QR codes to 248 households located within the presumed 0.9 km² distribution area of the panther chameleon population. They were asked about concerns regarding the occurrence of panther chameleons, but also about existing knowledge about invasive species in general. The residents were also divided into three areas: A core region where chameleons had been observed several times, a peripheral region with few findings, and an outer region where no chameleons had been sighted at all.

44 households answered the questionnaire.  In fact, all 11 interviewed residents in the outer region had not sighted any chameleons. Of the 33 residents interviewed in the core and peripheral region, about a third said they had already observed panther chameleons. The same number had seen the light of torches at night. 86% of the residents surveyed knew that panther chameleons are not actually native to Florida. Only a few residents said they were concerned about the occurrence. Seven residents had approached collectors with torches and said the collectors had all said they were looking for chameleons for research purposes. Only one of the collectors had said he/she was looking for animals to sell, according to the residents. One resident reported an altercation after strangers entered his property several times looking for chameleons. Another resident called the police because of a whole group of collectors on the neighbouring property.

Unfortunately, the questionnaire was given out after the search efforts of the authors themselves, so it is not apparent from the responses how many of the encounters were indeed with people looking for chameleons for sale purposes. The publication is also a preprint, so no review process has taken place yet.

Colorful lizards and the conflict of collection
Colin M. Goodman, Natalie M. Claunch, Zachary T. Steele, Diane J. Episcopio-Sturgeon, Christina M. Romagosa
Preprint, 2023
DOI: 10.1101/2023.08.10.552819

Picture: Alex Laube

Aggressive fungal pathogen discovered in panther chameleons

Aggressive fungal pathogen discovered in panther chameleons

by Alex Laube Tiermedizin Science

Fungi of the genera Nannizziopsis and Paranannizziopsis have long been known to cause severe skin diseases in various reptiles. These include species feared in herpetocolture such as CANV (Chrysosporium Anamorph of Nannizziopsis vriesii) and Nannizziopsis dermatitidis, which are apparently obligate pathogens. Now, a similar skin fungus has been detected in panther chameleons in Florida, USA.

Nine adult panther chameleons (Furcifer pardalis) were taken from a wild population in Florida. They were first housed in groups of two or three chameleons in screen cages with natural and artificial plants at a private keeper. A ReptiSun 5.0 lamp and a conventional light bulb were used. The animals were fed with crickets and zophobas every second day and supplemented with vitamins and calcium. All nine panther chameleons, plus a tenth that was captured later, were finally given to the United States Department of Agriculture (USDA) for a series of experiments. They were kept individually in steel aviaries outdoors.

Subsequently, the eight remaining panther chameleons were also examined. In fact, all but one of the chameleons were found to have either missing claws or swelling of the hands and feet, small skin wounds, circumferential proliferation on the body and/or yellow and black skin lesions. Fungal PCR was no longer carried out, but infection with the same pathogen was suspected. All nine panther chameleons still alive were treated with 25 mg/kg terbinafine and 5 mg/kg voriconazole, both given orally once daily.

After six weeks, the panther chameleons were examined again. The skin lesions were still present, in two animals the hand and foot swellings had decreased. After eleven to twelve weeks of treatment, all symptoms had disappeared in seven chameleons. The skin lesions had developed into scars. Only two chameleons still showed swelling in the foot area, but less than at the beginning of treatment. After 14 weeks of therapy, another panther chameleon died. The autopsy revealed kidney and organ damage as the cause of death. Since the contribution of the medication used to the death of the chameleon could not be ruled out, the therapy was terminated in week 15 for six of the eight panther chameleons. The two panther chameleons that still showed swelling of the feet were treated for another two weeks.

This case report is the first detection of Paranannizziopsis australasiensis in chameleons. So far, this fungal pathogen has only been found in green iguanas and Eastern bearded dragons in herpetoculture and in Tuataras, skinks, geckos, and snakes in nature. It remains unclear where the panther chameleons became infected. Three of the screen cages used in the initial private husbandry had previously been inhabited by Veiled Chameleons (Chamaeleo calyptratus) and Knight Anoles. The private keeper had disinfected the terrariums with chlorine bleach. The rest of his reptile population showed no skin lesions. The aviaries used later at the USDA had been empty for years and had previously only been inhabited by small birds. It is possible that the fungal pathogen had been introduced via potted plants from nurseries that regularly observe native reptiles on the premises. However, Paranannizziopsis australasiensis has not been found in any other wild reptile species in Florida to date.

The most likely scenario seems to be that the chameleons were already infected before they were caught in Florida, but the disease only broke out later. The original animals of the population could have been infected by bearded dragons in the pet trade a good decade ago. A latent infection with a late onset is supported by the fact that most of the skin lesions in this case report were found in winter, after temperatures had dropped below 10°C. Moreover, before the onset of symptoms, so-called “thermal limit trials” were carried out, in which the animals were briefly exposed to extreme temperatures of up to 45°C and 6°C. Another chameleon from the same population was caught at a later time and also developed skin lesions, which indeed suggests an infected population in Florida.

A free-ranging chameleon population infected with Paranannizziopsis australasiensis could pose a huge risk to native reptiles. The fungal pathogen is known to be highly infectious and aggressive. In addition, free-ranging panther chameleons in Florida are now being captured by dealers and sold to private owners, which could result in the spread of the disease in private reptile populations. Further research is urgently needed to clarify the extent of the current occurrence of Paranannizziopsis australasiensis in Florida, both in herpetoculture and in the wild.

Dermatomycosis caused by Paranannizziopsis australasiensis in nonnative panther chameleons (Furcifer pardalis) captured in Central Florida, USA
Natalie M. Claunch, Colin M. Goodman, Madison Harman, Mariaguadalupe Vilchez, Savanna D. Smit, Bryan M. Kluever, James F.X. Wellehan, Robert J. Ossiboff, Christina M. Romagosa
Journal of Wildlife Diseases (4), 2023
DOI: 10.7589/JWD-D-22-00018

Introduced chameleons in Florida

Introduced chameleons in Florida

by Alex Laube Science

The “Sunshine State” Florida in the southeast of the USA has long been known for a variety of introduced reptiles. Students at the University of Florida recently published a small brochure on the current status of chameleon species introduced there.

As early as the late 1800s, a non-native reptile was documented to have found its way to Florida by ship: an anole. Since then, some 150 introduced species have been documented in the US state, including eight species of chameleons. Three of them are now spread over the entire southern half of the peninsula and even reproduce: the Yemen chameleon Chamaeleo calyptratus, the Malagasy Giant chameleon Furcifer oustaleti, and the panther chameleon Furcifer pardalis.

Current known distribution of Panther, Veiled, and Malagasy Giant Chameleons in Florida.

All three species are thought to have come into the country with increasing pet trade and private keeping of chameleons. Furcifer oustaleti has been in Florida since at least the year 2000. At that time, the first findings became known in an avocado plantation located in the immediate vicinity of the buildings of a former importer in Miami – Dade County. Chamaeleo calyptratus was first recorded in Fort Myers on a vacant lot only a little later, in 2002. Furcifer pardalis followed in 2008.

The question of whether any of the three species mentioned should be considered invasive is difficult to answer so far due to a lack of data. A species is considered invasive if it is non-native, has been introduced by humans, and has been proven to cause damage to native flora and fauna. The last point, however, is debatable. While Jackson’s chameleons in Hawaii have been shown to consume endangered native snail species, among others, the same is not yet known from Florida. There, the animals are currently considered more of a nuisance, but with the potential to threaten the native invertebrate fauna.

The problem is that chameleons are still being released – sometimes they escape unintentionally, but sometimes they are deliberately released in order to collect and sell the offspring later. For the latter, you need a permit in Florida. Interesting to note: Anyone is allowed to kill introduced chameleons on their own property “in a humane way”. In some places, chameleons are already being collected to be sold to private owners.

The students call for observations of chameleons in Florida to be reported on the internet via IveGot1.org or via the app of the same name. So far, not all populations are known, as much information is only passed on by hand. Furthermore, they ask that chameleons that have become a nuisance should not be abandoned, but handed into the Exotic Pet Amnesty Program of the Florida Fish and Wildlife Conservation Commission. The surrender there is free of charge, and the EPAP is ultimately looking for new keepers for the animals.

Florida’s introduced reptiles: Veiled Chameleon (Chamaeleo calyptratus), Oustalet’s chameleon (Furcifer oustaleti), and panther chameleon (Furcifer pardalis)
Max Maddox, Karissa Beloyan, Natalie M. Claunch, Steve A. Johnson
Veröffentlichung des Wildlife Ecology and Conservation Department, Universität of Florida
DOI: 10.32473/edis-UW501-2022