Species:Black and white Tegu (Tupinambis merianae)
Favourite food: Meat (like rodents, chicks or insects)
How they got their name: She was named after Dora from the show “Dora The Explorer”
Natural behaviours: Sometimes she likes to show off how active she can be by trying to climb all over her handlers, Dora also greets new people by sticking out her tongue so she can smell them
Favourite thing to do at the Earth Rangers Centre: Dora loves digging in dirt and soaking in warm baths
Here’s what Animal Trainer Ashley has to say about Dora…
Dora is given a nice big tub of warm water every morning, and sometimes by lunchtime it’s already full of mud. That’s because Dora will dig in her dirt, then climb in her bath, then dig in her dirt, and climb in her bath… you can see how her tub would get dirty so quickly. When this happens, her bath will need to be rinsed out, and she’ll be given a whole new tub of water!
- They are the largest species of tegu lizard in the world, growing to over one metre in length
- These tegus are among the most intelligent and highly adapted of all lizards
- Tegus are opportunistic omnivores, meaning they will eat just about anything they can find
- They lay large clutches of up to 30 eggs in nests guarded by the mother
- Although their populations are stable, tegus are a favourite target of hunters for food and the sale of their skins
The Black and white tegu is the largest species of tegu lizard and can be found in parts of Eastern and Central South America. They are sometimes called Argentine Giant Tegus since they are the world’s largest tegu and grow to over one metre long.
Black and white tegus have strong claws for digging burrows and finding food. Their sharp teeth and strong jaws make it easy for them to chew through the toughest meat, but they also come in handy for defending themselves. When threatened, tegus will also use their powerful tail as a whip. If a predator grabs hold of their tail, tegus can release it at what’s called a fracture point. When this behaviour happens the predator will be left with a wiggling tail while the tegu has a chance to get away. The tegu’s tail will regrow but it won’t reach the same length. Although Black and white tegus spend most of their time on dry land, they are also pretty good swimmers!
Tegus use their long, forked tongues to “smell” the air around them. The tongue collects scent particles in the air and transfers them to the Jacobson’s Organ on the roof of the their mouth. This organ detects chemical signals that are then sent to the lizard’s brain to help the animal learn about its surroundings, such as the direction of prey, particular habitat characteristics or how close a predator might be. This process is called chemoreception.
During the cooler weather in fall and winter, Black and white tegus have “brumation” periods, which is like hibernation. During brumation they seek cover in underground burrows to rest, becoming very lazy and sluggish and moving about only to find water. By resting like this, the tegu’s metabolism slows down so much they do not have to eat to keep their body functioning! Once spring arrives with warm weather, brumation ends and the tegus are ready to search for some food.
Black and white tegus make their homes near forested areas in Argentina, Paraguay, Bolivia and Brazil. While they like forest-edge savannah habitats, which are grassy clearings that border on the edge of forests, Black and white tegus can be happy and comfortable in a lot of different environments; they only need access to food, a little water and shelter. They can be found in old growth forests or newly planted ones. They do well in untouched natural areas, but can also survive in large open areas created after the building of roads and agricultural development.
Since they aren’t picky about their habitats, Black and white tegus can also survive in areas outside their natural range in South America. For example, some tegu lizards that were once kept as pets have escaped or been released into the wild in parts of Florida, including the ecologically sensitive everglades. Once introduced like this, tegus can become a nuisance for local wildlife, or worse, they can disturb nesting sites of endangered birds and reptiles as they look for eggs to eat.
The Black and white tegu plays many important ecological roles in its ecosystem, largely because of its eating habits. Tegus, especially when they are young, eat tons of insects and insect eggs. Feeding on insects helps control the local insect population.
Since they also eat fruit such as berries, tegus are important seed dispersers. When tegus eat fruit from a plant, they gulp the fruit down, seeds and all! Later, after they’ve digested their food, they will “excrete” the seeds along with other waste, helping plant communities spread in size.
Last but not least, tegus can help control the spread of disease to other animals by cleaning the carcasses of dead animals that they may find in the forest.
By playing their part, Black and white tegus help keep their ecosystems well-balanced, biologically diverse and free of infectious disease. Their highly adaptable diet also comes in handy when trying to survive in areas where humans have changed the landscape for farming or housing. While many species find it challenging to share spaces with humans, tegus can get along very well by eating the insects, rodents and plants that live around our houses and farms.
Black and white tegus eat a lot of different foods. They are omnivorous and are very opportunistic, which means they will rarely turn down a meal, even if it’s not part of their usual diet. Tegus are foragers, using their excellent sense of smell and powerful claws to dig around on the forest floor or under fallen logs for food.
Tegus eat insects such as crickets and spiders, as well as eggs, snails, small rodents, berries, bananas, seeds and flowers. Clearly, tegus aren’t fussy eaters, and they will even eat some things that other animals wouldn’t dare to eat. Millipedes, for example, give off nasty tasting liquids to protect themselves from predators. While this is effective against a lot of animals, it does not stop tegus from gulping them down in large numbers. Tegus are also very quick to eat carrion, animals that are already dead. That might seem gross to us, but eating dead animals takes a lot less energy than hunting, and all that protein is important to keep a tegu healthy!
Tegus are oviparous—this simply means these large lizards lay eggs. Tegus will usually breed after their brumation period (the time when they are resting over the winter), and will lay 12 to 30 eggs in their nesting sites. Female tegus are very protective of their nests! That’s why the females lay eggs in a burrow with two chambers. One chamber holds all the eggs while the mother lives in the other chamber where she can guard the nest. If everything is just right, females can lay eggs every year, but if conditions are too hot or dry, or they haven’t found enough food, they may rest instead.
When Black and white tegus first hatch from their eggs they are just 20cm long and are usually yellowish-green with dark markings. This camouflage colouration helps the baby tegus blend into their environment during their first few weeks of life. As hatchlings, tegus are carnivorous, eating A LOT of bugs, providing tegus with the protein necessary for rapid growth. After a month or so, they begin to lose this colour pattern and develop the black and white skin for which they are named.
- Least Concern (IUCN, 2010)
- They are a favourite target of hunters for meat and the sale of their skins
Black and white tegus are listed as a species of least concern. This means that, given their numbers in the wild, the conditions of their habitats and their interactions with people, they are believed to not be at risk of becoming endangered anytime soon.
Just because a species is listed as least concern doesn’t mean we don’t have to be careful! Tegus are hunted or trapped in areas of Argentina and Paraguay for many reasons. Tegu fat is used for medicine, and their meat is used as food for people and dogs. Sometimes these lizards are caught live to be sold in the pet trade, but tegu skin is sold to make leather goods.
The international trade and sale of tegus is legal, but hunting tegus is important for many people living in South American counties. Currently, local governments are doing a great job at making sure the hunting of tegus is done sustainably (in a way that doesn’t put tegus at risk of becoming endangered). There are programs to educate hunters and teach them how to help keep tegus healthy in the wild. Conservation groups also help hunters get involved in habitat protection programs to make sure wild tegus have enough space to live. By keeping tegu populations healthy through monitoring hunting and habitat protection, hunters won’t lose their livelihoods and tegus should continue to thrive in the wild.
References: Fitzgerald, Lee A. “Tupinambis Lizards and People: A Sustainable Use Approach to Conservation and Development”. Conservation Biology. 8:1(1994) 12-15 Johnson, Steve A. “Tegu Lizards”. Department of Wildlife Ecology, University of Florida. , Keifer, Mara Cintia and Ivan Sazima. “Diet of juvenile tegu lizard Tupinambis merianae (Teiidae) in southeastern Brazil”, Amphibia-Reptilia. 23:1(2002) 105-109, Norman, David R. “Man and tegu lizards in Eastern Paraguay”. Biological Conservation. 41:1(1987) 39-56