Give Them A Taste of their Own Medicine
Ben Berg
Chemoecology 8.10.2009
Since their introduction to mainland Australia in 1935, the cane toad (Bufo marinus) has significantly decreased biodiversity amongst reptiles in Australia. Scientists are now growing desperate in their attempts to limit the growth of this species. Researcher Mattias Hagman conducted experiments involving biological control mechanisms to fight the toad invasion.
Working in conjunction with Team Bufo (a team of cane toad researchers) and receiving funding from the Australian government, Hagman tested lab results that suggested that a pheromone produced by larval toads lowered survival rates. Toad larvae were placed into two groups in outdoor ponds, and the treatment group was exposed to the pheromone. The pheromone, which is emitted by injured larvae to alert other individuals, caused the tadpoles to undergo accelerated metamorphosis, causing a smaller body size and reducing survivorship by 50%. While this significantly effected cane toad populations, it appeared to have no effect on native species. The authors have called for follow-up research on the topic.
February 8th, 2010 at 12:03 pm
This sounds really interesting. However, I would be interested to know how feasible it would be to implement this as a population management strategy. For instance, what concentration of pheromone is necessary in order to induce premature metamorphosis? Also, I think it would be important to understand the reproductive behavior of the toads who do survive A common strategy among species that experience a significant bottleneck in their lifecycles is to reproduce at astonishingly high rates. 50% survivorship is meaningless if you get a twofold increase in reproduction!