Melissa Montemayor

Mr. Skipper

Encounters 8

March 5, 2023

The Invasive Cane Toad’s Résumé

Introduction

        There are countless species that have their own problems such as being endangered or invasive. Both the invasive and the endangered species should receive attention because both impact the environment. One of the reasons animals are endangered is because an invasive species is taking hold of them. So, an invasive species should be the one getting more care since its influence is more powerful on the habitat. For example, the cane toad is an invasive species that is affecting anything in its way. Not only is it invading the land, but it is also eating or poisoning other species in the same habitat. These cane toads may seem like normal amphibians at first, yet they are problematic toads. Even though the cane toads were first expanded throughout the lands, it was all done just because of one small mistake at the airport. The one small error made a big act on everything and everyone. The invasive species are hazardous because they have extreme effects on habitats, other species, and even people.

Taxonomy & Description

Cane toads are large toads that are invasive species and have several interesting qualities. The genus of the cane toad is Rhinella and the species is the marina. They are part of the Animalia kingdom and their scientific name is Bufo Marinus (Freedman). Although they look like any other toad, cane toads are much bigger and more threatening.

The cane toad is a giant earthbound toad that weighs almost three pounds and is a darker color with warts. Cane toads produce thousands of eggs in water and some other species of frogs can be poisoned by the eggs. They have golden irises with ridges from the eyes down to the snout and the tadpoles have a dark back with a “silvery white belly with black spots'' (Freedman).  These toads have a pair of glands that produce neurotoxins that go down from behind the eyes and have long legs that help them travel a lot more quickly than other frogs. 

The large toads were first found in Hawaii in 1932 and were mainly reported around islands. The cane toads were first going to be used by farmers to protect their sugar canes (Israel). They are carnivores that eat vertebrates or smaller frogs. Sometimes they live in urban environments, eat dog or cat food, and even change their breeding places into urban ones. The toads have a “strong sex drive” and they are also “lazy hunters”, but they are smart to wait around a street light for flies to fall down right to them for an easy treat (Israel). The cane toads are a dangerous species, but also incredible for their characteristics. 

Introduction to Non-Native Habitat 

The cane toads were native to America, yet they have an unusual process on how they became invasive. They were first found and belonged in the southern and central parts of America, but they were introduced to Australia which is where they become invasive. Their original use was to eliminate cane beetles causing problems for farmers and their sugar cane fields. The cane toads were supposed to be eating and getting rid of the beetles, but the toads took over. 

The cane toads that made it to Australia “conquered more than 386,000 square miles” (Israel). These toads that completely failed to solve the farmer’s problem with the cane beetles also invaded Australia. So, not only were the toads an invasive species there, but they also failed to get rid of the cane beetles for farmers. In 1935, there were suitcases with toads going from Puerto Rico to Hawaii and Australia traveling for the protection of the crops (Israel). From maybe a hundred to a few thousand toads were transported to Australia, but the cane toads soon conquered thousands of square miles and reproduced into thousands. 

This was not the only place where the cane toads invaded the land. There was another incident in the Miami airport where “a pet importer released about 100 cane toads” (Johnson). It remains unknown if the release was on purpose or not, but that was not the only time it happened. There have been other occurrences after that where other intentional releases have happened in Florida. Since the cane toads have been released multiple times, they soon invaded south and central Florida.

Even though they took over and are mainly known for being in Australia and Miami, they were introduced to other islands like Hawaii and Puerto Rico. They spread almost 2 kilometers in one night which is much more than other toads or frogs.  These toads used to spread 10 kilometers per year, but now the number spiked up to 60 kilometers per year (Randolph). The cane toads were introduced as an invasive species many years ago, but they still keep spreading.

Adverse Effects

These dangerous cane toads have not done anything but harm the areas they have invaded. They have adverse effects on three different things. The list states ecological, environmental, and economic effects. All the damage made hurt many things. 

The cane toad has a threatening behavior towards the animals in the habitat. One species, in particular, was really affected by the cane toad and it was the Native northern quoll (Randolph). This species was pushed to endangerment and the quolls would already struggle to survive. Loud calls coming from the toads also affect people’s sleep. The toads would also leave pets with seizures, red and pink gums, or foam at the mouth (Johnson). Cane toad eggs are poisonous and affect the water and any native animal exposed to them. There is much more to the list of negative effects cane toads have on animals. 

The environment is unsafe when the cane toads arrive. There are several reasons why these toads are bad for the environment. Apart from messing with the food chains, the toads make surviving more difficult. The waters are poisoned due to their eggs and causing “the deaths of koi fish” and other animals in the water (Johnson). Many organisms have even adapted to resist the cane toad’s poison. Because these toads invaded most of the habitat, the native anuran, and the rainbow bee-eater have experienced habitat loss (Randolph). There have also been dead cane toads in water leading to contamination and intoxicating the fish. Affecting the environment and habitat is a big problem cane toads have created.

Besides the harmful effects, the cane toads have made, the attempt to find the right solution is costly. Trying to solve the invasion problem is already complicated, and toad control is also very expensive for the number of toads. Even though it was known that controlling the cane toad population would be extremely difficult, there was “$20 million Australian dollars ($17 million USD) spent on toad control” (Israel). Most of the solutions found or created have not worked such as traps, pesticide spraying, or killing them. Even if scientists do find a way to solve this problem, the money spent and planned to spend will be plenty. 

Conclusion: Study, Control, and Eradication

The cane toads have been spreading ever since they were released with no obstacles in their way. There has yet to be an actual solution to eradicate the cane toad. All of the ideas scientists have tried have not been successful, but there are small things to do to avoid them. 

Studies and control of these cane toads are still in progress. Even though cane toad control is very expensive, it has already been tried multiple times. Most of the things scientists have tried to make to eradicate cane toads have utterly failed or they have had negative impacts. There was a pesticide spray made, but it did not take long for scientists to find out that the spray causes cancer in humans, and the spray was soon banned (Israel). Things people could do to get rid of local cane toads is pick up the toads with a plastic bag, turn it inside-out, and then tie it shut so they could be put in the freezer for a humane death (Johnson).  Removing any source of light, moisture, or debris will discourage cane toads from going. It would also be important to take care of pets because they will eat cane toads which leads to poisoning. Although the removal of cane toads will be difficult, there are smaller solutions for others.  

It will remain unknown if there will ever be a solution to this problem. Even if there is a way to solve this problem, it will be very complicated to successfully get everything under control. Hopefully, the cane toad’s spotlight will burn out soon.

Works Cited

Freedman, J.A., and L.A. Somma, “Rhinella marina”. USGS: Science for a changing world, United States Geological Survey, 21 Sep. 2022, nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=48. 

Israel, Brett. “Cane toads invade, conquer Australia”. Live Science, 24 June 2010, www.livescience.com/29560-cane-toad-conquest-invades-australia.html.

Johnson, Steven A. “The Cane or ‘Bufo’ toad (Rhinella Marina) in Florida.” Ask ifas, University of Florida, 25 May 2020, edis.ifas.ufl.edu/publication/UW432.  

Randolph, Dalia A. “1.2 Cane toad: purposefully introduced, but instantly a regret”. Pressbooks, Ohio State U, ohiostate.pressbooks.pub/sciencebitesvolume2/chapter/chapter-2/. 

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