Species of the Month: Cane Toad

Picture of Cane Toad

Adult Cane Toad

by Raymond Gonzo, OSU zoology major

The other day I was working in the Amphibian section of the Tetrapod collection, when I saw two toad specimens that really stood out to me. The toads were almost the size of a Coke can, which is bigger than the American toads that you may find in your backyard. Another interesting thing I noticed about these toads was the fact that one specimen was collected in Fortin de las Flores, Mexico, and the second specimen came from Australia. How is it that these two specimens were collected on different sides of the planet? On the jars they were labeled Rhinella marinus, which struck a cord with me. I had heard that name many times before, but I couldn’t remember from where. A quick check through the Tetrapod Collection’s curatorial database revealed that the amphibian in question was none other than the infamous Cane Toad.

The Passenger Pigeon that I wrote about last month was a species that declined in numbers and went extinct due to human activities. The cane toad, Rhinella marinus, is an example of the opposite effect, a species that proliferates with human help.

Until the 1930s, the cane beetle, an Australian native whose larvae feast on the leaves of sugar cane, did excessive damage to the sugar cane crop. In order to control the beetle population, the cane toad was released as a new predator. The idea being that this toad would feast on the beetles and thus protect the sugar cane crop. However, it did not work out as planned, the cane toad became a major pest in itself.

Instead of controlling the beetles, the toads began eating everything in sight, which allowed them to thrive and reproduce at an alarming rate. If that weren’t enough, the toads are highly poisonous and release a deadly toxin if a predator, who has not evolved defense strategies against cane toad toxin, should try to eat them. In the Americas, there are predators who can eat the toads and consequently keep their population in check. For example, there are many crocodilian reptiles, snakes, and various species of fish that are both immune to the toxins and can be found in the toads’ natural habitat. Many Australian predators of frogs and toads are unfamiliar with the toxins and cannot tolerate them, which means they will often die from eating a cane toad. This has given the toads a chance to drastically increase in numbers. Interesting fact, the cane toad is in the same family (Bufonidae) as the American toad, Anaxyrus americanus, an example of related species having a very different effect on their environment, especially when displaced.

However, as recent studies show, over time species may evolve the ability to either recognize and avoid cane toads or be able to tolerate their toxins. In 2004, Ben Phillips and Richard Shine demonstrated that some Australian snake populations that are at risk of death by the cane toad have adapted to living with the invaders. The authors of this study found that snakes increased in size in areas where they co-exist with cane toads. Small individuals face a much higher risk of fatal poisoning by toads, thus over time this species has been selected for large body size. More recent studies have shown that spiders and ants may also help keep cane toad numbers in check. If you are interested in finding out more read this article in the Australian Geographic. You can also read the study conducted by Phillips and Shine.

There are hundreds of instances where animals from one part of the world are introduced to another area, and often times there are disastrous consequences. A local example of this is the Emerald ash

borer. The ash borer is a native to China, but turned into an invasive pest of ash trees in North America. Here at the Ohio State University, much research is being done on the impact these beetles are having on the local Ohio ecology. More information on the control of this pest can be found here.

When it comes to trying to control nature, mankind has a pretty mixed track record of both successes and failures. Invasive species such as the Norway rat, the feral pig, and the ball python are all examples of how carelessness can lead to the destruction of an ecosystem. The Cane Toad is just one in a long line of destructive invasive species, and with the increased inter-continental travel of the modern world, it certainly won’t be the last.



Phillips, B. L., and Shine R. 2004 Adapting to an Invasive Species: Toxic Cane Toads Induce Morphological Change in Australian Snakes. PNAS 101, 17150-7151.



Observations from the Freshman-Brought to you by Raymond

If I said that I had planned to work at The Ohio State University’s Museum of Biological Diversity from the beginning of my college career, I’d be lying. If I said that I was aware of the museum’s existence before last October, I’d still be lying (I know. I’m just the worst).

If I were to spin a yarn about how I first got started at the museum, it would begin last semester when I was frantically searching for an undergraduate research position. As a zoology major entering my third year of college, I thought to myself, I should probably start getting zoology work related experiences to put on my resume and undergraduate research seemed the most appealing. The problem is that Sasquatch is easier to find than a professor doing zoology-related research and who is looking for an undergraduate to participate. So after much searching, emailing, crying, etc… I asked the undergraduate research office where I could go to find said professors looking for undergraduate workers. They replied that most of researchers could be found, or have an office at the University’s Museum of Biological Diversity.

Upon hearing this, my initial thought was, “We have a Museum of Biological Diversity?” My second thought was, “We have a Museum of Biological Diversity and I’m just hearing about this now?”  I took a bus out to Carmack Corner, walked up a dirt road and found this place on the very edge of the University’s land. When I first discovered the museum, I was so incredibly intrigued and excited about what could be inside. Upon further investigation however, I was incredibly disappointed to see it wasn’t an “actual” museum but more akin to the warehouse from the end of Raiders of the Lost Ark.

A picture of OSU's Museum of Biological Diversity. A very plain looking brick building.

There is the building in all its glory. When I say that this museum is out of the way, I mean it is really at the far western end of campus.

It wasn’t until the beginning of this semester that I had heard about the museum’s annual open house. I had been told that this is the one day of the year that the museum resembles the general public’s view of what an actual museum rather than a warehouse, so I decided to attend. The open house was a wonderful experience for a zoology major, such as myself. After entering the building, I was soon surrounded by specimens of exotic and colorful birds and skeletons from a wide variety of different animals. After seeing all this awesome stuff, I thought to myself, “Gosh wouldn’t it be just swell to work/intern/volunteer here?” So I had met with the curator, Dr. Angelika Nelson, and began to volunteer my time labeling and organizing specimens in the museum’s Tetrapod collection.

So it’s been a little over a month since I started at the museum (I refer to myself as a freshman for a reason) and now I have a chance to really look back and reflect on what I’ve done so far. All that I’ve really done (again, I’ve only been here a month) is print labels, organize loans, do some geo-referencing and maybe (if I should be so lucky) count how many 100-year old hummingbirds we have in our collection. Make no mistake; museum work is not for everybody. At times it can seem like long, tedious and mind-numbingly boring work.

But I love every minute of it.

I’m sure that if the average person were to come to the museum and try to do what it is that we do there, they’d either recoil in disgust or fall asleep from boredom. And that’s fine, it’s not everybody’s cup of tea. For me however, working at the museum is one of the greatest jobs I’ve ever had. Animals, in general, just wholly fascinate me and I grew up watching the old Animal Planet. When I printed labels for specimen cabinets, I got to look at some of the most exotic and unique bird species I’ve ever seen. Not to mention that I got to touch three of the endangered bird species the Tetrapod collection possess: an Ivory-Billed Woodpecker, a Passenger Pigeon and a Carolina Parakeet (I can die happy now). Working there is basically nirvana for a guy like me.

A head on picture of the Tetrapod Collection's Ivory Billed Woodpeckers.

Not going to lie… These are the most exciting specimens I have seen so far.

While working at the museum is incredibly fascinating and fun, I’d be lying (again) if I said there was only one reason why I love it there. Going into the museum and doing all this science-related work makes me feel like I’m getting closer to actually being a zoologist. For anyone who is a zoology major at OSU, I don’t need to tell you how difficult the major program is. I spent the first two years of college trying my absolute hardest just to get through the math requirements (don’t even get me started on that ungodly chemistry program). So working here (along with actually doing major courses) makes me feel as though I’m becoming a “big kid” in my field.

I’ve often said that the greatest decision that I ever made was joining the Boy Scouts. However, I think I may have topped myself by choosing to work at this museum. I love the work that I do in the Tetrapod collection and it helps me feel as though I’m actually doing something worthwhile with my time. If you’ve enjoyed reading about my experiences, then you’re in luck. My latest responsibility for the museum is to write more of these blog posts, so the fun never has to end. Until next time dear reader.

Raymond is one of our newest volunteers in the Tetrapod Collection who will be interning with us this coming fall. His current projects here included working with our amphibian and reptile collection.

Museum specimens inspire artist

Last night (24-January-2015) was the opening of Samantha Parker Salazar’s new show Malleable Matrices at the OSU Urban Arts space in downtown Columbus. Anna Smith, Emily Archibald and myself followed Samantha’s invitation to the reception.

Samantha is a recipient of the John F. Fergus Family Fellowship, and a printmaking lecturer at The Ohio State University. She is known for her intricate cut-paper installations. One of her new pieces, Waking Red, is a vortex of cut forms and vibrant colors. It features images of amphibians and reptiles which she photographed at the OSU Tetrapod collection last December.

intricate cut-paper installation

Waking Red by Samantha Parker Salazar

detail of Waking Red

detail of Waking Red

You can visit the exhibit through Thursday, January 29, 2015 at the OSU Urban Arts Space
at 50 West Town Street, Columbus, OH 43215