Agama Lizards in Florida

Peter's Rock Agama Lizard
Photo:  Gary Nafis

Peters’s rock agama (Agama picticauda) lizards are now well established in Florida but unlike other exotic reptile species they appear to be most comfortable in urban areas along the east coast and are not obviously posing any immediate threat to native wildlife, anymore than the millions of humans that are occupying the same space from Brevard County south.

Florida is now home to more non-native species of reptiles and amphibians than anywhere else in the world. South Florida is especially at risk because of its thriving trade in exotic pets. Although pythons have become the symbol of the state’s losing battle against invasives, non-native lizards also pose a significant threat to native wildlife and ecosystems. Tegu lizards, for example, are happy in many different environments including the Everglades and will eat almost everything, including small mammals, bird eggs, fruit, insects and even pet food.

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Peter's Rock Agama Lizard pair
Photo:  Gary Nafis

There are approximately three times as many species of established, nonnative lizards in the state as there are native species (Krysko et al. 2016). These established species range in size from the small (to 6 in.) Cuban brown anole (Anolis sagrei), to the large (to 7 ft.) Nile monitor (Varanus niloticus). Among Florida’s approximately 50 species of nonnative lizards are four species within the family Agamidae. 

Peter's Rock Agama Lizard
Photo:  Gary Nafis

Agamid lizards are native to Africa, Asia, Australia, and Europe. Most of the roughly 500 known species are most active during the day and are visual hunters that feed on insects and other invertebrates (Vitt and Caldwell 2014). Within a species, males are often more boldly colored than females, at least during the breeding season.

So when scientists at the University of Florida noticed a recent increase in sightings of a flashy red-headed lizard, they knew it was time to ask the public for help in fighting yet another invader.

Peter's Rock Agama Lizard
Photo:  Gary Nafis

A surge of emails to the university’s Institute of Food and Agricultural Sciences Extension from people all over South Florida asking for identification of the reptile was a sign that the Peter’s rock agama lizard, an invasive species from Africa, was multiplying and its range appeared to be expanding, with observation reports from as far south as Big Pine Key.

The most widespread of the four agamid species with established populations in Florida is Peters’s rock agama, which occurs in numerous scattered populations, mainly along coasts in the Peninsula. 

Peter's Rock Agama Lizard
National biological Information Infrastructure, Bugwood.org
Photo:  Lauren Humphries

Peters’s rock agama (Agama picticauda) are striking nonnative reptile species in Florida most notable because of the males’ colorful skin and relatively large size as compared to Florida’s native lizards. Adult males can grow to 12 in. including the tail, but females don’t grow quite as large. In addition to their size difference, males and females may look very different. In Florida, adult males in breeding condition are boldly marked with an orange or red head, a black body, and a black-tipped tail immediately preceded by orange coloration.

Peter's Rock Agama Lizard Close up
Bugwood.org
Photo:  Rene Marcinhes

The head coloration of mature, non-breeding males is not as bright, and the back is lighter colored. Breeding females are drab compared to breeding males, lacking orange or red coloration on their heads and tails, although females with eggs have yellow or orange patches on their body. They are brownish gray with light green spots and short stripes on their head and neck, and they frequently have a light band on the back of the thigh that extends onto the tail.

The agama was first introduced to Florida in 1976 through the pet trade. After escaping or being released or both, sub-populations started growing in Homestead and several areas in Miami-Dade County. South Florida offered the perfect spot for resettlement: a hospitable subtropical climate and large areas of disturbed habitat.

Peter's Rock Agama Lizard
Photo:  Steven Johnson, University of Florida

EXOTIC PET TRADE INTRODUCED AGAMA TO FLORIDA

Peters’s rock agama are native to East Africa (The Reptile Database 2020). They were first introduced to Florida in 1976 via the pet trade (Wilson & Porras 1983; Nuñez et al. 2016). Initially believed to be the closely related red-headed agama or African rainbow lizard (Agama agama africana), a study of the lizard’s DNA by University of Florida graduate student Leroy Nuñez showed otherwise (Nuñez et al. 2016). Based on this study, it is believed the species was introduced several times in the state by way of the exotic pet trade (Nuñez et al. 2016). The same reptile dealer was responsible for releasing the species in Homestead, Miami-Dade County, and Palm City, Martin County, where these populations have expanded widely (Enge et al. 2004).

A big problem the lizards pose is that they love insects, including butterflies. That may spell trouble for South Florida’s endangered butterfly species, including some that live in developed areas where the exotic lizard prefers to hang out.

Peter's Rock Agama Lizard females
Photo:  Gary Nafis

Although their diet in Florida hasn’t been studied yet, evidence from their native range shows that agamas feed on a variety of bugs and small invertebrates. Unlike invasive iguanas, which are much more numerous and eat plants, the agama prefers insects.

“We have seen video footage of a large male attempting to eat a monarch butterfly. Though the butterfly escaped, it lost a wing and likely died shortly thereafter,” said the report. The agama may also eat other invaders like the Cuban brown anole, and in their native range of East Africa they have been observed eating small mammals, birds, small reptiles, fruits and vegetation such as flowers and grass.

Though there is no evidence to suggest that the agamas are eating local butterflies on a consistent basis, they may eventually share the same habitat as the endangered Florida Leafwing and the gray Bartram’s Hairstreak, which live in pine rockland forests in Miami-Dade, Johnson said.

Miami Blue Butterflies, Florida's Most Endangered
(Cyclargus thomasi bethunebakeri)
Florida Museum of Natural History
Photo:  Jaret Daniels

And because the agamas are also in the Keys, scientists are concerned they may decide to have a taste of one of the rarest insects in the US, the Miami blue butterfly. But the risk is low because the last pockets of the little bug are in undisturbed areas like Long Key and Bahia Honda state parks, too wild for the apparently city-loving agama, Johnson said. In the Keys, multiple sightings have been registered in Key Largo, Marathon and Big Pine Key.

“At this point we don’t see the agama as a huge threat to local wildlife like the Burmese python or the tegu, but we know that the populations are growing in South Florida, and we know they eat insects and other invertebrates,” said Steven Johnson, a UF/IFAS associate professor of wildlife and ecology.

Peter's Rock Agama Lizard female
Photo:  Gary Nafis

Scientists are just starting to map out their distribution, but it appears that agamas tend to prefer urbanized areas rather than the Everglades, though they have been spotted surrounding the national park. South Florida residents have probably seen at least one of these colorful lizards perched on a light post or strolling around a parking lot.

The lizards hitched rides on trucks and even trains and spread north, being recently spotted in locations from Martin County to Brevard County and as far north as Jacksonville.

The public can engage in citizen science by reporting Peters’s rock agama sightings using the EDDMapS website.

More great Gary Nafis photos at this site: California Herps Gary Nafis photos

LITERATURE
Barbosa, C. A. R. 2017. "Interspecific Interactions of Two Invasive Lizards in an Urban Environment." Unpublished MS Thesis, University of Florida. 78 pp.

Blunden, T. K., and K. L. Krysko. 2007. “Agama agama africana (African Rainbow Lizard) Reproduction.” Herpetological Review 38: 73.

Enge, K. M., K. L. Krysko, and B. L. Talley. 2004. “Distribution and Ecology of the Introduced African Rainbow Lizard, Agama agama Africana (Suaria: Agamindae), in Florida.” Florida Scientist 67: 303–310.

Gray, R. J. 2020. "Exotic Hobos: Release, Escape, and Potential Secondary Dispersal of African Red-Headed Agamas (Agama picticauda PETERS, 1877) through the Florida Railway Systems." BioRxiv. https://doi.org/10.1101/2020.05.11.089649

Krysko, K. L., K. M. Enge, and P. E. Moler. 2019. Amphibians and Reptiles of Florida. Gainesville: University of Florida Press. 706 pp.

Krysko, K. L., L. A. Somma, D. C. Smith, C. R. Gillette, D. Cueva, J. A. Wasilewski, K. M. Enge, S. A. Johnson, T. S. Campbell, J. R. Edwards, M. R. Rochford, R. Tompkins, J. L. Fobbs, S. Mullins, C. J. Lechowicz, D. Hazelton, and A. Warren. 2016. “New Verified Nonindigenous Amphibians and Reptiles in Florida through 2015, with a Summary of Over 152 Years of Introductions.” IRCF Reptiles & Amphibians 23: 110–143.

Meshaka, W. E., B. P. Butterfield, and J. B. Hauge. 2004. The Exotic Amphibians and Reptiles of Florida. Malabar, FL: Krieger Publishing Company. 155 pp.

Moore, J. A. 2019. “Agama picticauda (Peter's Rock Agama) Dispersal.” Herpetological Review 50: 360.

Nuñez, L. P., K. L. Krysko, and M. L. Avery. 2016. “Confirmation of Introduced Agama picticauda in Florida Based on Molecular Analyses.” Bulletin of the Florida Museum of Natural History 54: 138–146.

Powell, R., R. Conant, and J. T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America. New York, NY: Houghton Mifflin Harcourt Publishing Company. 494 pp.

The Reptile Database. www.reptile-database.org. Accessed 23 June 2020

Vitt, L. J., and J. P. Caldwell. 2014. Herpetology: An Introductory Biology of Amphibians and Reptiles. London, UK: Elsevier Inc. 757 pp.

Wilson, L. D., and L. Porras. 1983. “The Ecological Impact of Man on the South Florida Herpetofauna.” University of Kansas Museum of Natural History Special Publications 9: 1–89.