Why Were Cane Toads Introduced?

Cane Toads are well-known for the problems they have caused over the years, as they have had drastic impacts on the surrounding ecosystems. Many issues were not foreseen, as Cane Toads were introduced to numerous regions worldwide with the prospect of aiding the environment. 

While Cane Toads are native to South America, they were introduced to new regions in the 1930s to lower the population of destructive agricultural beetles. The introduction aimed to aid the growth of cane crops. But, the species soon overpopulated areas, posing risks for surrounding wildlife. 

Cane Toads are classified as an invasive species, and the aftermath is due to their inherent qualities. Join me as I discuss why Cane Toads were introduced to certain regions, where they were introduced, and how their introduction has impacted the relative ecosystems over time. 

Why Were Cane Toads Brought Outside South America?

Cane Toads were initially restricted to their native regions in South America, but were intentionally transported by humans and introduced to new regions worldwide. The primary objective was to allow the species to feed on destructive cane-related agricultural pests, yet the plan backfired.

The idea seemed entirely appropriate since Cane Toads have an enormous appetite, feeding on anything large enough to fit inside their mouths, from bugs to small snakes, birds, bats, mice, and lizards.

However, there were quite a few issues with the entire plan, including the fact that the Cane Toads cannot climb. Toads cannot jump or climb and the beetle bugs they were introduced to kill lived in the upper parts of the cane stalks. Therefore, Cane Toads did not go after the beetles, but fed on anything and everything else in their path.

Where Are Cane Toads From?

Cane Toads are native to South America, including the following regions: 

  • Costa Rica
  • Panama
  • Columbia
  • Mexico
  • Nicaragua
  • Venezuela

Cane Toads thrive in grassy and wooded areas. However, they also inhabit urban spaces such as backyards, golf courses, and gardens. These amphibians find shelter under leaf piles or man-made structures and materials, such as tarps that retain moisture.

How Cane Toads Affected Local Ecosystems

Apart from the fact that the Cane Toads did not solve the pest issue in all areas of introduction, some regions experienced massive levels of destruction to native wildlife. Cane Toads are highly adaptable, large, omnivorous, and toxic, making it challenging for neighboring species to thrive and reproduce. 

They feed on almost anything and frequently devour native species with ease. Cane Toads lay up to 30,000 eggs twice per year, their tadpoles are also toxic and mature much faster than most amphibian species. Their presence has overwhelmed some areas and threatened the continuation of many iconic species. 

Where Were Cane Toads Introduced?

The most notable locations where Cane Toads were introduced are Florida and Australia. However, Cane Toads were introduced to various regions worldwide, before and after the introductions conducted throughout the 1930s.

Cane Toads were introduced in the following locations:

The Caribbean The PacificWorldwide 
Antigua
Barbados
Cuba
Dominica
Grenada Island
Carriacou Island
Guadeloupe
Grand Cayman Island
Haiti
Dominican Republic
Jamaica 
Marie Galante
Martinique
Montserrat
Nevis
St. Kitts
St. Lucia
St. Vincent
TortolaIsla de Guanaja
Aruba 
Australia
Japan
Taiwan
Guam
Papua New Guinea
Philippines
Cook Islands
Micronesia
Fiji Islands
Kiribati
Republic of the Marshall Islands
Solomon Islands
Republic of Palau and Tuvalu
Bermuda
Egypt
Mauritius
Thailand
Korea
USA

Not all introductions have had dire outcomes, as some regions have benefitted from their introduction while others have witnessed few Cane Toads to date.

State First ObservedLast ObservedLocations
Florida (FL)19362021Widespread
Hawaii (HI)19322019Hawaii
Kauai
Lanai
Maui
Molokai
Oahu
Louisiana (LA)19351935East Central Louisiana Coastal
Massachusetts (MA)19911991Nashua
Mississippi (MS)20142014Upper Leaf

The above table indicates when Cane Toads were first observed in different states across the USA, as well as the specific regions within each state (CTNF). Cane toads can be found in multiple places in the United States including Florida, Hawaii, Louisiana, Massachusetts, and Mississippi.

Why Were Cane Toads Introduced to Florida?

Cane Toads were introduced in Florida in Canal Point and Belle Glade, Palm Beach County. The introduction involved 200 Cane Toads throughout the 1930s and 1940s, and the plan was for these amphibians to help control pests in sugarcane crops.

Florida experienced a dramatic spike in Cane Toad dominance. Current populations are believed to result from escapes and releases by importers throughout the 1950s and 1960s.

Cane Toads are still observed in the following areas throughout Florida:

  • Big Cypress Swamp
  • Caloosahatchee
  • Cape Canaveral
  • Charlotte Harbor
  • Crystal-Pithlachascotee
  • Everglades
  • Florida Bay-Florida Keys
  • Florida Southeast Coast
  • Hillsborough
  • Kissimmee
  • Lake Okeechobee
  • Lower St. Johns
  • Manatee
  • Northern Okeechobee Inflow
  • Oklawaha
  • Peace
  • Peace-Tampa Bay
  • Santa Fe
  • Sarasota Bay
  • Southern Florida
  • St. Andrew-St. Joseph Bays
  • St. Marys
  • Tampa Bay
  • Tampa Bay
  • Upper St. Johns
  • Vero Beach
  • Western Okeechobee Inflow
  • Withlacoochee

Today, Cane Toads are commonly found in people’s backyards and on golf courses across Florida. It’s important to ensure pets do not interact with theses toads since the can be fatal in case of ingestion.

Why Were Cane Toads Introduced to Australia?

In 1935, Cane Toads were imported from Hawaii and introduced to Queensland, Australia to eat beetles that feed on sugar cane that had been grown in Queensland since the 1860s.

The introduction of Cane Toads in Australia is the most notable example of their potential for havoc. Australia has hundreds of frog species, but had no toad species before Cane Toads were introduced.

White grubs give birth to 13 native beetle species, which fed on sugar cane roots resulting in widespread crop death. The Cane Toads were supposed to feed on these beetles but ate almost every other animal, including other local frogs, snakes, reptiles, mammals, and amphibians.

They were imported, bred, and released by Reginald Mungomery, a government entomologist working for BSES, after Cane Toads’ introductions resolved similar issues in Hawaii, the Philippines, and Puerto Rico. Walter Froggatt, another Australian entomologist, voiced his concerns regarding the potential for destruction and chaos after the Cane Toads’ release. 

Only 2,400 Cane Toads were released in 1935, bred from 102 imported Cane Toads. Still, they reproduced over the 85 years, totaling approximately 200 million Cane Toads to date. Scientists estimate that Cane Toads expand across northern Australia at a rate of approximately 31 miles each year.

More About Cane Toads

Cane Toads are magnificent survivors, genetically stronger than many other frog species and willing to tackle anything in their path. Authorities have established laws to aid the process of reducing their impact on native species. They are still conducting investigations and programs to alleviate the related risks, slow down the spread, and lower population numbers in certain areas.

Learn more about Cane Toads on our blog: