Hello all! Last year you may remember a blog post I made on the impacts of Argentine black and white tegus where they are introduced in Florida. Since last year there has been some further development on what tegu species are residing in Florida, what the tegus are eating, and how easy it is to accidentally lose a beloved (and expensive!) pet.
As a quick recap of my previous post: the Argentine black and white tegu is a large lizard native to South America – specifically Brazil, Paraguay, Uruguay, and Argentina. These lizards can reach up to four feet in length, spend most of their time on land, but can swim and remain submerged for long periods. These critters are intelligent, and when kept as house pets can be very attached to their owners and quite docile – making them wonderful pets. However, as the tegu grows very large it can become more work than their owners care to give, many owners and individuals who sell animals in the pet trade become irresponsible and release their Tegu into the wild. Occasionally, beloved pets are lost when not kept in a secure outdoor enclosure, not watched appropriately, or accidentally get loose and run away.
Currently there are three species of tegus in Florida – the Argentine black and white tegus (Salvator merianae), Gold tegus (Tupinambis teguixin), and Red tegus (Salvator rufescens).
The Argentine black and white tegu is the most apparent of all tegus in Florida. They have established populations in south Florida and central Florida, which occurred from two separate incidents of introduction. In the past year it has been seen that these tegus eat many vertebrate species including lizards, turtles, birds, rodents, and snakes in addition to native and nonnative plant species and insects. They pose a huge threat to ground nesting birds, American Alligators, and American Crocodiles, as they love to consume eggs. The Argentine tegus also have a “morph” or a genetic combination that is seen in the pet trade called a “Blue Tegu” which have also been seen in south Florida. These Blue Tegus are thought to be escaped pets, which range from $300-$400 in retail price at pet stores, while regular black and white tegus retail for under $200. Althought they are of special color morph, these blue tegus are still Argentine black and white tegus which means they can survive and damage the natural ecosystems in Florida.
The Gold tegu is very similar to the Argentine tegus. They are from South America, and have been trapped in Florida since 2008. They can grow up to three feet in length, and usually live in the tropical forests of northern and central South America, and Panama. In their native range they are known to feed on insects, invertebrates, small mammals, reptiles, birds, fish, and fruit. This means they are likely eating similar item sin Florida, although nothing is currently known about their dietary habits. What is known about the Florida population is that they are reproductively active. Hatchling, juveniles, and adults have been captured over the past decade. It is theorized that the Gold tegus have been introduced via the pet trade industry. To read more about the Gold tegu in Florida this paper by J. Edwards et al. is a great place to start! These animals retail for approximately $50, but they are also not as commonly kept as pets due to their naturally aggressive temperament.
The red tegu has been seen recently in the popular video on social media posted above! Quite a wonderful companion. This is one of the largest of the Tupinambis species and usually grows to be four feet in length or longer. They are powerful tunnelers and love to dig where they are native. They use these burrows for refuge during the day and night, as well as shelter for their eggs. They are known to eat birds, rodents, eggs, and other reptiles - making them another prime candidate for impacting the environment in Florida! There have been a total of eleven sightings since 2007 that span through seven counties in Florida. The Red tegu goes for a retail price of $200-$300, and for this reason it is also thought that the animals seen were escaped pets.
All three species of tegus go through brumation (reptile hibernation), where they reduce activity and resign to burrows for the cooler months of the year. This is one of the many reasons why tegus are such a formidable invasive animal in Florida! They have potential of surviving much further north than even the Burmese python. As you can see, these animals do cost quite a pretty penny. The red tegu, Argentine Tegu, and Blue tegus all retail for $200 or more, and it is common to see household pets brought in from neighborhoods, parks, and other urban areas. They are great diggers and will escapes outside enclosures, porches, fences, and even harness/leash if they put their mind to it! The most commonly encountered tegu are still wild Argentine tegus, but it is interesting to see what other morphs and species are also present in the Florida ecosystem! I hope you all have enjoyed the update.
About the Author: Jenna is a graduate student at the University of Florida. Currently she is studying Wildlife Ecology and Conservation while working in south Florida to manage invasive animals. Jenna primarily works with the Argentine Black and White Tegu and other invasive lizards.
The Common Agama, Rainbow Lizard
The Common Agama is native to Africa and can comfortably occupy urban, suburban, rural and undeveloped habitats. In Africa they occur in desert, dune, savanna, forest, rainforest, and mountainous areas. This lizard is yet another non-native species that can be found in southern Florida. They occur in Dade, Charlotte, Broward, and Seminole counties; likely posing threat to native insect and small vertebrates. There are several subspecies of agamas, and Florid has a mixture of West African subspecies and East African subspecies. The West African subspecies have bright orange-red heads that fades to a blue-indigo body, and end with a lighter blue-white tail tipped with black. They can reach up to 12 inches in length and are a diurnal species which can be seen moving around during the daytime.
The diet of these lizards consists of mostly grasshoppers, ants, beetles (James and Porter 1979), flowers, grasses, and discarded human food (e.g., candy, bread, cake, carrot pieces (Romer 1953, Chapman and Chapman 1964, Harris 1964, Cloudsley-Thompson 1981). Adults have also been known to eat their own young. They display behaviors similar to that of Bearded Dragons – the adults will perform head nods, head bobs or push-ups, and basking. The head nods and head bobs are commonly used as challenge displays between males, or to entice females who are wearing their reproductive colors. Basking is common in the morning between 10 AM and noon, with the dominant males holding the best basking position, followed by the sub-males, and then females.
Female agamas will lay two clutches of eggs each breeding season, usually between the months of June through September. The sex of the eggs is determined by the temperature of the soil, with males being produced in warmer temperatures than females. In Florida the lizards are established and have been breeding for at least ten years in Charlotte and Dade county, and for less than ten years in Broward, Seminole, and Martin counties; there is also a population in Monroe county which has not yet been reported as breeding.
Links and papers:
Chapman, B. M,. and R. F. Chapman. 1964. Observations on the biology of the lizard Agama agama in Ghana. Proceedings of the Zoological Society of London 143:121-132.
Clodusley-Thompson, J. L. 1981. Bionomics of the rainbow lizard Agama agama (L.) in eastern Nigeria during the dry season. Journal of Arid Environments 4:235-245.
Harris, V. A. 1964. The life of the rainbow lizard. Hutchinson Tropical Monographs. 174pp.
James, F. C, and W. P. Porter. 1979. Behavior-microclimate relationships in the African rainbow lizard, Agama agama. Copeia 1979:585-593.
Romer, J. D. 1953. Reptiles and amphibians collected in the Port Harcourt area of Nigeria. Copeia 1953:121-123.
Iguanas have become one of the most common invasive reptile seen in southern Florida. You can find them in trees, crossing streets, eating the flowers in your garden... Two of the more well known species of iguanas in Florida are pictured below - the Black Spinytail Iguana (Photo by Jeff Whitlock, 2013) and the Green Iguana (Photo by Save the Prairie Society, August 3, 2017).
Black Spinytail Iguana (Ctenosaura similis)
This species is native to southern Mexico, and was first noticed in Florida in 1978. Currently it has established its self breeding populations in Dade, Lee, and Charlotte counties in Florida. Adult males of this species can reach four feet in length, and females remain smaller. These lizzards are primarily terrestrial species, and are extremely wary of humans. When they feel threatened these iguana will retreat to their burrows for safety, however they are able to climb quite well if they are unable to safely reach their burrow (Bartlett and Bartlett 1999).
The habitats that this iguana is able to exploit are very broad. They can be found living on coastal uplands, in exotic plant communities, low density suburban developments, agricultural fields, and areas surrounding core urban areas and small towns. Over the years this species has spread across south Florida. First thought to be established in Lee county (1980), then Collier county (1998), and finally Broward county (2002); this species was introduced due to released or escaped animals intended for the pet trade.
The distribution of Black Spinytail Iguanas in Florida, 10 February 2018.
Green Iguana (Iguana iguana)
The Green Iguana is a large lizard that is also nonnative to Florida. This species, like the Black Spinytail Iguana, was introduced through the pet trade as well. The Green iguana lives terrestrially, and can be seen on the ground and in shrubs and trees all over suburban developments, urban areas, small towns, and agricultural areas. They are excellent swimmers, can tolerate fresh and salt waters, and can remain under water for up to four hours at a time. Male Green iguanas can grow over five feet in length and weigh just under 20 lbs, while females usually do not exceed 7 lbs at full maturity.
Originating in Central America to the tropics of South America and some eastern Carribbean islands, the Green iguana was first reported in Florida in the 1960s in Hialeah, Coral Gables, and Key Biscayne. Now the popualtions spread along the Atlantic coast in Broward, Martin, Miami-Dade, Monroe, and Palm Beach Counties; along with the Gulf Coast in Collier and Lee counties.
Distribution of the Green Iguana in Florida (EDDMAPS, 10 February 2018)
Status in Their Native Ranges
Although the Green Iguana has not been formally assessed in its native range, both it and the Black Spinytail Iguana are listed as being of least concern where they originate from. This means that they are exhibiting characteristics of a healthy population that is reproductively active and not exposed to any threats which may cause them to become threatened, endangered, or extinct.
Diet and Impacts
The diet of the iguanas includes a wide variety of vegetation. They are known to eat shoots, leaves, blossoms, and fruits of plants including nickerbean, hibiscuses, garden greens, jasmine, orchids, roses, Washington fan palms, squashes, and melons. They also occasionally feed on bird eggs, carrion, insects, and tree snails.
Due to their diet, iguanas pose a threat of damage to residential and commercial landscape vegetation and are considered a nuisance animal by property owners. They are most attracted to trees with fruit and flowers, with the exception of citrus. The dig burrows, which can erode and collapse sidewalks, foundations, sea walls, berms, and canal banks. They pose a threat to native and endangered species of tree snails, as well as have the potential to spread diseases and infectious bacterium Salmonella to other reptiles and to humans through water contact or surfaces contaminated with feces.
Iguanas can be legally removed year round with land owner permission. They are not protected by any laws except for the anti-cruelty laws. Florida Fish and Wildlife Conservation Commission (FWC) encourages the removal of Green iguanas on private land by landowners, and captured iguanas can be kept as personal pets or humanely euthanized. The iguanas cannot, however, be relocated and released at other locations.
In order to deter iguanas from your own property you can alter the habitat around our home ot humanely harass the animals until they leave. Some effective methods are: removing plants that act as attractants; filling in holes to discourage burrowing; putting wind chimes or other items in the yard to make intermittent noises; hanging CDs or other reflective material outside; and spraying the animals with water.
Iguanas in the Florida Keys
Dealing with Iguanas
Iguana Assistance for Homeowners
The spectacled caiman got its name from the bony ridge between its eyes which give it the appearance of wearing a pair of glasses. These caiman can grow up to approximately nine feet in length, with females being of smaller size than males. They have a stout snout, and a triangular ridge of skin atop each eye which give the appearance of a type of 'eye brow'. Mature individuals are olive-green with faint black spots and banding on their tails, this coloration is usually more distinct in younger individuals. Its coloration overall is quite variable, with some individuals having different coloration, sizes, and skull shape - these features have led to distinction between three subspecies of spectacled caiman.
Range and Biology:
This species is widely distributed compared to other crocodilians. The spectacled caiman and its subspecies can be found in Mexico, Peru, Brazil, Venezuela, Columbia, Bolivia, and Ecuador - it has also been introduced as a nonnative species in Cuba, Puerto Rico, and Florida, USA. Theses animals thrive in all lowland wetland and riverine habitats, preferring bodies of still water like lakes, ponds, and marshes. They are also tolerant to moderate salinity.
The caiman is highly adapted for water life. It is a superb swimmer and aquatic predator. The adult caiman feed on fish, amphibians, reptiles, and water foul - particularly large individuals have also been know to take on mammals including deer and pigs! In dry conditions when food sources are scare this species is also known to cannibalize smaller individuals.
The spectacled caiman was first sighted in Florida in 1960, and span across two counties in the state. It poses threat to a variety of native vertebrates and competes for food and space with the native American alligators. They are presumed to have been released or escaped from the pet trade, and can be found in Broward and Dade counties throughout marshes, lakes, ponds, and canals. These crocodilian are susceptible to colder weather, which has confined them from moving further north. There have been efforts to remove the caiman populations, and in 2001 a nest of 41 eggs was found and collected, and 39 of those eggs hatched in captivity. Since 1970 there have been no reports of breeding, however the populations are still present.
Last month one of our bloggers had the chance to travel to Vancouver, British Columbia in Canada for the Children & Nature Network Annual Conference & International Summit. There were oodles of panels and “walkshops” teaching educators, administrators, and other environmentally-focused people best practices for leading classes to students of all ages. There were even classes with doctors discussing the benefits of time in nature on a person’s physical and mental health.
The biggest focus was how to get the whole family outside and interacting with nature.
The plan was to achieve this through running Family Nature Clubs, which are exactly what they sound like: kids and adults, from babies through senior citizens, enjoying time learning about nature and playing in it with other families in their community. Lots of organizations run these, but they can also be totally informal and run by its own members. We heard from speakers who run these clubs all over the world, including in the United States.
There are tons of resources online, especially through the Children & Nature Network where these clubs were first coined. (Scroll down for the “Nature Club Toolkit for Families” in English and several other languages).
What was really surprising was that there is even an app for parents of 0-3 year olds to help them have nature activity time! This app, GROW With Nature Play, is a parenting tool which lists hundreds of nature activities, organized by age appropriateness, which parents can use after they’ve gone home and put their child to rest for a nap, to track what they’ve done that day. Activities can be as simple as looking at a bird flying by!
The Grow With Nature Play app was created by an Austialian father who wanted to be sure his kids were experiencing nature and family time daily from the start of their lives.
The ideas didn’t stop there. We talked about how to make activities fun and educational for families with mixed ages-- trying to get a 6 year old and a 16 year old enjoying the same things can be scary even for seasoned teachers! As much as kids may act like they don’t want to be with the family, they overall enjoy hanging out with their siblings and don’t like to be divided by age, so partner them together. We learned a really important tip that sometimes adults forget: teenagers like to know they’re trusted, as they’re trying to come into their own as indivuals and young adults, so give them some responsibility, like watching the kids or guarding the first aid kit.
When it comes to activities that kids of different ages just can’t physically do or understand in the same way, find ways to work around it. For example, nature photography is a great way to get everyone exploring. Preteens and up like to get creative with their camera angles and lighting or finding something really challenging to take a picture of, while for littles they just want to play I Spy. Both are alright! You can even make a scavenger hunt or activity sheet for each age range: for the youngest, instead of writing the words, use drawings, like of a flower or leaf, to tell them what to look for.
A few more activities that kids of all ages can enjoy:
As one speaker said, “They don’t need to understand the biology to develop the wonder.” People of all ages just love spending time with animals and nature!
If you try any of these activities with your family (or find a new one), let us know how it went! Later this year we’ll let you know too.
Kids have great eyes to spot well-camouflaged creatures like this Northwestern Mole Salamander (be sure to always use clean hands devoid of chemicals or oils before handling any amphibian, their fragile skin absorbs everything!)
Sarah is a conservation educator and trained zookeeper currently working at an AZA (Association of Zoos and Aquariums) accredited zoo in New Jersey while also starting a freelance nature program in Jersey City. Her education specialties include urban environmental programming and access, while her keeping specialties are focused on small mammals, arthropods, and birds of prey.
About the blog
Ferrets and Friends, LLC has four writers bringing you information on a variety of topics from pets to wildlife, education to conservation, and from new developments in our business to information about our industry. Learn something new each week!