Australia imported 2,400 toads to save its crops – now those 200 million are an unstoppable scourge

The post Australia imported 2,400 toads to save its crops — now 200 million of them are an unstoppable disaster appeared first on AZ Animals.

Take it fast
Cane toads were introduced to Australia in 1935 to control sugarcane beetles, but toads Ignore it Beetle It was to protect them while destroying the ecosystem.
Instead, they became one Highly toxic invasive species with no natural predators.
Cane Toads threatening Many native reptiles, mammals, birds, and amphibians.
Despite decades of effort, large-scale control of sugarcane toads is nearly impossible.

In 1935, endemic beetles were wreaking havoc on the Australian sugar cane crop in Queensland. Beetle larvae live in the soil and chew sugarcane roots, stunting growth or killing the plant. Looking for a natural solution to kill the grass, the Australian government imported cane toads from Hawaii, with the hope that the toads would eat the grubs and save the cane. Unfortunately, the worst-case scenario happened. The toads did not keep the beetle population in check. Instead, they became Australia’s most destructive invasive species and an ecological disaster.

An introduction to the history of Australian destroyer Ken Todd

By the late 1800s, sugarcane had become a major crop in Queensland. Settlers discovered that Queensland’s humid and warm climate was perfect for growing plants. However, farmers may use native beetles, especially the grayback cane beetle (Dermolepida albohirtumAs the larvae were destroying the crop by eating the sugarcane roots. The Queensland Bureau of Sugar Experiment Station (BSES) was established by the government in 1900 to help farmers.

Entomologists working for BSES studied several methods for controlling beetles, eventually settling on a relatively new science: biological control. At the time, entomologists were experimenting with the new idea of ​​bringing in natural predators to control pests. That’s how the cane head got in.

Ken Todd’s to the rescue

Ken Todd’s (Rhinella marina) The largest toads in the world. They are opportunistic hunters and feed on a diet of insects, small animals, plants, and even pet food and garbage. Cane toads are 10 inches long and weigh up to 4 pounds. These giant toads are also highly poisonous, as are the eggs and tadpoles. Toads secrete a toxin called bufotoxin, which can kill animals that try to eat them and can irritate the skin or burn the eyes of people who handle them.

As you can imagine, introducing cane toads to Queensland caused more problems than they solved. Cane toads are native to Central and South America. However, in the 1920s and 30s, they were introduced around the world to control pests. Today, they are considered an invasive species in Australia, the Caribbean Islands, Hawaii and Florida.

In August 1935, the BSES released 2,400 cane toads into a sugarcane plantation at Gordonvale in northern Queensland. It was not a well thought out plan. According to the National Museum of Australia, “Remarkably, no studies were conducted on the potential impact on the environment. Nor did the Bureau of Sugar Experiment Station determine whether the boy would actually eat the cane beetle.”

Cane toads thrive in warm environments. However, they did nothing to control the bird. Today, beetle grubs are controlled using soil-based insecticides in sugarcane cultivation.

What species are most affected by cane toads?

By the 1950s, the Australian government declared the cane toad an invasive predator. Threats from toads include poisonous animals that prey on them, competition for native species for resources, and their voracious appetites.

According to the Queensland government, 75 species of Australian crocodiles, lizards and freshwater turtles are threatened by the toad. Some of the animals at risk of dying after eating sugar cane include Australian monitor lizards, koalas, tiger snakes and freshwater crocodiles. Many of these animals are designated as endangered species.

A research study has shown that native tadpoles suffered a mass die-off shortly after toads were introduced to Queensland. The study found that 1,300 tadpoles of 10 different species died in one season. Birds are also affected by toads. For example, cane toads eat the eggs and nests of rainbow bee-eating birds. Research has shown that cane toads cause one-third of bee-eaters’ nests to fail.

Finally, sugarcane toads have indirect effects on native species by altering the ecosystem when they arrive in an area. Toads have large appetites and eat many insects. Eventually, invertebrate populations begin to decline, which reduces the amount of resources for other species. These cascading changes can have wide-ranging implications for complex food webs.

Why cane toads are so difficult to control

As of 2010, the Australian government declared, “No broadscale method is likely to be available to control sugarcane toads across Australia.” Introduced as a boon to sugarcane farmers, it has turned into a plague that is rapidly spreading across the continent. Scientists estimate that the range of cane toads expands at a rate of 25 to about 40 miles per year.

Cane toads have no natural predators or diseases that threaten them in Australia. In Central and South America, they are kept in check by natural predators that have evolved with them. For example, many South American snakes are either immune or have some level of resistance to the cane toad’s bufotoxin.

Also, cane toads are opportunistic feeders and will eat anything, even pet food and people’s trash. They breed opportunistically, usually in warm and wet conditions, and can reproduce several times a year. Females lay 8,000 to 30,000 eggs at a time. To understand how cane toad populations can explode, consider that most native Australian frogs lay about 1,000 to 2,000 eggs a year.

Efforts to control Ken Todd continue

Experts offer ways to control cane toads if they are found in a small area or small pond. They suggest collecting cane toad eggs from water or humanely removing adult toads. Community groups provide information on how to identify adult cane toads and humanely remove them from the environment. However, these control measures are only feasible for small areas and cannot be applied to large populations of sugarcane toads.

Despite the challenges, researchers are finding new ways to control toads. Scientists have found that they can edit the DNA of a cane toad egg to prevent it from developing into a tadpole. If scientists can find a way to gene-edit large numbers of eggs, they may find a way to control cane toad population growth.

In another study, scientists had success with conditioned taste aversion (CTA) in freshwater crocodiles. Some crocodile populations in Australia have declined by more than 70 percent due to cane toad ingestion poisoning. In the study, the researchers kept cane toad carcasses with the poison removed, but a nausea-inducing chemical was added. While crocodiles in the control sites continued to eat the poisoned cane toads and become ill, those in the treatment sites stopped trying to eat the cane toads.

Another project that began as a citizen science initiative involves designing a tadpole trap capable of holding thousands of tadpoles. And in an effort to protect the Pilbara from hopping invaders, scientists are looking for ways to prevent the toads from accessing the water. Cane toads cannot survive more than a few days without access to water.

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