The delayed posting of number 2 in my Top 5 Science Fails:
“There was an old woman who swallowed a fly”
It is not often that you can say this but, this is an example of a situation where scientists should have read their children’s literature. The story of the “old woman who swallowed a fly” is a fantastic tale of how biological control can get out of hand, as eventually after spiders, birds, cats, dogs and more you could end up having to swallow a Horse!
In June 1935 the Bureau of Sugar Experiment Stations decided to introduce the Cane Toad to combat the native Cane Beetle. They released 102 of the young around the Cairns area. After the initial introduction the programme was halted while they tested the potential environmental effects of the toads. They found no cause for concern and in September 1936 resumed the programme.
However, there was a problem, the toads do not eat the adult beetle and the larvae live underground where the toads can not get to them. This would have been a forgotten side note in failed ecological control if that was all that happened. However, despite having minimal effect on the Cane Beetle the toad’s impact on other native species was a lot more pronounced.
From the initial toads introduced there are now estimated to be 200 million toads and are still spreading out and inhabiting new territories. The toads possess a toxic gland between the eyes which releases bufotoxin, which is toxic to many of the indigenous animals of Australia. The effects of the this toxin has been seen in the populations of many different native creatures.
Whilst some predators have worked out ways of getting around the toxin, such as the Black Kite which flips is over and eats its underside, this is still a big problem, and with the annual migration rate estimated at 25 miles per year the problem isn’t getting any smaller. However, the typically resilient Autralians have kept themselves amused during the toad epidemic with toad hunts, occurring alongside toad racing, cane toad cricket and cane toad golf, which can be seen below:
The Bureau of Sugar Experiment Stations deserves its place on this list for not only originally incorrectly introducing the Cane Toad species to Australia, but for then, after concerns about the potential effects of the toads deciding to introduce more!