Florida is home to a variety of different native frog species (27 to be exact) as the warm and wet climate here makes it a perfect habitat for these small amphibians. However since Florida is a great home for frogs, a few invasive frogs have taken advantage of our lush ecosystems. These invasive species can cause harm to our native frogs and to us and our pets too! Today we will be teaching you how to tell these invasive species of frog from their similar-looking, native counterparts. With some practice and information you will be to tell the difference between invasive and native frogs!
Green Treefrog (Native) vs Cuban Treefrog (INVASIVE)
Green treefrogs can range from green to grey and have distinctive white stripes down each side. Though, occasionally they can lack stripes. Compared to the Cuban treefrog, their eyes are smaller and do not appear “bug-eyed”, and they have smaller, rounded toe-pads. These frogs can be found throughout the state, including the panhandle. Green treefrogs only grow to 2.5 inches in length.
The Cuban treefrog can have many different colors ranging from whitish to grey, green, and brown. Compared to the green treefrog, eyes of the Cuban treefrog are larger and appear to be bulging. They also have larger toe-pads. They can grow up to 5.5 inches, which is quite large for a treefrog, and can be found in peninsular Florida. The Cuban treefrog is an aggressive predator, eating insects, small frogs and lizards. Because of this, Cuban treefrogs pose a threat to native frogs. In some areas Cuban treefrogs have caused population declines of native treefrogs. Cuban treefrog tadpoles are also able to out compete two species of native tadpoles and were actually shown to hinder the growth and development of native southern toad and green treefrog tadpoles. Additional research has shown native squirrel treefrog tadpoles have a lesser chance of survival when Cuban treefrog tadpoles are also present. If you think you see one of these frogs, you can humanely euthanize them following guidelines found here.
How to tell them apart:
The easiest way to tell these two species apart is by looking at the toe-pads of the frogs. Cuban treefrogs have larger toe-pads than that of green treefrogs. Also look for the distinctive white stripe down each side of the frog because that is a distinguishing characteristic of green treefrogs. Next, take a close look at the size of the frog; if the frog is over 2.5 inches in length then it is most likely a Cuban treefrog. Our native treefrogs don’t get much bigger than that. You can also look for bumpy skin on the Cuban treefrog as most native treefrogs have very smooth skin.
Southern Toad (Native) vs Cane Toad (INVASIVE)
The southern toad is a small toad, only growing up to 3 inches. The head of this toad has two distinct ridges on top of the head, between the eyes. Also this toad has small bean-shaped poison glands on its shoulder. This toad can be found anywhere in Florida and is native to the southern United States.
The cane toad is the largest of the toad species found in Florida, growing up to nine inches long! This massive toad lacks ridges on the top of the head and has large, triangular poison glands on the shoulder. Cane toads can be found along a wide strip spanning from the central-west coast, southeast to the east coast of Florida down through the Everglades (see range map here). The Cane toad is an invasive species and can be very problematic. These toads are poisonous and unfortunately, many animals and pets can get severely ill or even die if they attempt to eat this species. If you think you see a cane toad, verify your identification by sending a picture to your local UF/IFAS Extension office. One ID is confirmed, you can humanely euthanize them to prevent harm to you, our native species and your pets. Find out more here.
How to tell them apart:
The easiest way to tell these two apart is by size alone. If you find a toad larger than three inches then it is most likely the cane toad. Be sure to look at the head and see if there are any ridges. If there are no ridges then it could be a cane toad. If it has two ridges between the eyes, then it is a Southern toad. Both of these frogs have glands that secrete a milky substance. Be sure to note the shape of the glands. Glands on the southern toad are bean shaped while the glands on the cane toad are triangular. Keep in mind the secretions from the cane toad are highly toxic, capable of irritating your skin or burning your eyes. It can also kill cats and dogs if ingested. If you think you have a cane toad in your area, send a picture to your local UF/IFAS Extension office for verification. If you have found a cane toad outside of its currently documented range (see below), please contact Dr. Steve A. Johnson at firstname.lastname@example.org
Blog written by: Steven Krupka, Lara’s intern and graduate of USF with a degree in Environmental Science & Policy. Blog edited by: Lara Milligan.