Cane toads

Sometimes in the past, man’s haste and inexperience has resulted in some undue stresses to the environment. Some of these decisions were made in an attempt to eradicate unwanted pests, who were causing hardships to farmers and landowners. As many Australian’s will attest to, introducing a new species is not necessarily the right answer. Back in 1935, the Cane toad was introduced to the region during their struggle to control Cane beetles. The beetles were responsible for the ruination of many crops, and people’s livelihoods were at stake. If only we had then, been offered a glance at what was to come. Present day Australia, is virtually dominated by these overgrown amphibians. Opinions regarding their introduction are mutually negative, in both Australia and in other countries that utilized them. Hardships to native species from food competition and the cane toad’s venom, position them in serious risk. Control measures have proved to be weak and futile, as their populations continue to grow at alarming rates.

In Australia these brutes are known as cane toads, although elsewhere in the world they are known as marine toads and/or giant toads. “Giant” is a fair representation of their enormous sizes, as it is possible for them to reach lengths of 15cm and weights of up to two pounds. The other characteristic summed up with the adjective “giant” would be their insatiable appetite. Their unquenchable hunger places some serious stresses on the indigenous species. Rivalry over food sources is not uncommon, except when you take into consideration the uncontrolled populations of the cane toad. Without natural control factors, the cane toad community is able to grow beyond normal limits, and could possibly eliminate most if not all local food sources. When the balance and harmony of nature is disturbed, the region can suffer some serious repercussions.

Cane toads are native to South and Central America, although due to minimal predation, “occur at a density 10 times greater in Australia, than that of their native home.” There appearance is a little unsightly, with bony ridges on their foreheads and parotoid glands on their head. This species is inundated with warts, and yes it is an old wives tale that handling toads will cause warts on the handler. Basically it is their toxic venom that allows them to thrive as they do. Native species in Australia do not have natural immunity to the cane toad’s venom as they do in it’s native home. As well, the venom is not only localized to the glands, and can be found on the skin’s surface. So exposure to the venom can happen quite easily. In defense, these gargantuan toads possess the ability to propel their venom up to two meters, especially when highly agitated. Their venom can be a problem for humans and is able to cause intense pain and temporary blindness.

These ground dwellers do not have a specific breeding period. As long as there is sufficient food and water supplies, females may lay up to thirty thousand eggs in just one month. Amazingly, this considerable number of eggs only requires a meager pool of water to prosper. This type of hardiness and flexibility is one of the factors that make the cane toad a successfully introduced species. Not all species are able to adapt as well as they have. Another factor in their favor is that the males do not need a female to reproduce. Males possess a rudimentary ovary and are able to breed alone if necessary. This plus the fact that they’ll mate with every female they come across, ensures a healthy population. Another interesting fact is that cane toads develop quicker than other indigenous species. Within three days the eggs have hatched and shortly afterwards, the tadpoles are actively hopping and moving around. This species has a fairly long lifespan, and have known to live upwards of twenty years.

Since their introduction, they have proved to be a robust and forcible invasive species. This has resulted in issues with their population control. As of March 2001, their populations had breached the Kakadu Reserve in Australia prompting immediate attention. Due to it’s “archaeological and ethnological significance”, the voracious eating habits of the cane toad could result in some serious destruction. Housed on this reserve are many rare and protected species; protected from man, but not the cane toad. There was research conducted regarding the use of viruses from Venezuela to exterminate the toad. This ended up being impossible, as the virus would have also attacked and endangered some indigenous amphibians.

One of the species put at risk is the frog eating, red-bellied black snake. It does not have a natural immunity to the cane toad’s venom, nor does it avoid it as a meal. It is situations like these that make the cane toad an unfavorable species. The cane toad has been effective in controlling other insect problems. Although the destruction caused by them far outweighs the benefits in insect control. It has been approximated by experts that their groups advance just under twenty new miles each year.

In regards to their invasion of the Kakadu Reserve it has been said that, “no one has ever taken the time to understand the impact of the cane toad on insects, native birds and also native reptiles that are active right throughout the dry season around water holes…” The next attempt in controlling them involves gene alteration. Scientists are hoping to modify their genes, restricting their development. All the developmental stages of the cane toad are poisonous, so even some aquatic species are at risk from their venom. Therefore the number of species negatively affected by their presence is insurmountable.

The venom from the cane toad is similar to LSD, with its effects on humans. Apparently the mucus from the toad’s body is dried and smoked as a recreational drug. There have been documents that refer to “toad licking”, although it is unknown to this author whether people actually participate in this activity. The chemical in this venom, which causes the hallucinations, is known as “bufotenine”. Ironically along with recreational use, the venom is also used in Chinese medicine for treatment of various afflictions. One other use for the cane toad is research and study. Specimens are used in labs and schools to understand it’s biological processes. It is unfortunate that this amount of research was not done prior to their introduction. Then we could have prevented much of the demolition left in their wake.