Ask Otus: The truth about tegus

Otus Rufous, an Eastern Screech-Owl, was born on Siesta Key and is a full-time resident there.

An avid hunter, accomplished vocalist and genuine night owl, Otus is a keen observer of our local wildlife and knows many of nature’s secrets.

Otus will answer your questions about our amazing wildlife, but only if you Ask Otus.  So please send your questions and photos to  Thank you.

Dear Otus,

We live by Turtle Beach Park. Last Friday (Aug. 17) I read an article in a local weekly about a “rogue tegu lizard” living here. I took what I thought was a picture of the tegu, but it doesn’t look at all like the lizard in the photo accompanying the article. What is it? I was real excited to have taken this photo. We don’t have anything like it in Wisconsin.

Rick. W./Photo by Rick W.

Dear Rick,

You have every reason to be excited. Your superb photo is of an Argentine black and white tegu (Tupinambis merianae). The tegu’s markings are quite clear and you have captured its huge, red, exploring, forked tongue. What adds to your photo is the inclusion of the adult snowy egret. By comparing sizes, I can estimate your tegu to be less than 3 feet in length: it is probably a juvenile.The Argentine black and white tegu (also called an Argentine giant tegu) is the largest of all the tegu species. The male can grow up to 4.5 feet and can live some 15 to 20 years in the wild.

Unless caught, this tegu will wreak havoc on our key. It is a voracious omnivore with a particular fondness for eggs — especially those of our native sea turtles, alligators, crocodiles and snakes.  What’s even scarier is that tegus will go after bird eggs! You see, there aren’t too many of my Eastern Screech Owl family members left on our key, so I’m very concerned by this new threat to avian survival.

A fascinating element of a tegu’s haecceity is that they can run on their hind legs! Check out this super cool video by wildlife cinematographer Ojatro (Heiko Kiera). You’ll be amazed: Ojatro has filmed some of the most astonishing footage ever taken of invasive species in the Florida Everglades and their interaction with our native ones.

Rick, thank you very much for writing! And please send me updates with photos.


P.S. – The lizard in the weekly’s photo is an approximately 2-year-old female black spiny-tailed iguana (Ctenosaura similis), another invasive predator on our key. Tegus and iguanas are not the same.  For example, tegus eat iguanas. To learn more about the iguana threat to Siesta Key, please click on the following link:

The weekly mistakenly identified its photo of an iguana as a tegu.  That is what confused you.

Anyone sighting a tegu, iguana, other lizard or large snake is asked to report the sighting by calling the Sarasota County Call Center at 941-861-5000.