1 / 20

Invasive Biology: The Cane Toad

Invasive Biology: The Cane Toad. By: Adriana Carpio & Juan Escobar. Abstract.

barney
Download Presentation

Invasive Biology: The Cane Toad

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Invasive Biology: The Cane Toad By: Adriana Carpio & Juan Escobar

  2. Abstract • Invasive species are a great threat to global diversity, coming in second place to habitat destruction by humans (Greenless et al, 2006). Although some species of animals are beneficial to the economy and posterity of many cultures, there are usually several drawbacks. In many cases, a foreign species which was introduced to reduce or eliminate a pest becomes a pest itself. As in the case of Cane toad (Bufo marinus), reckless introduction has had a negative impact on native fauna. The cane toad has changed many of the native environments through different mechanisms such as interspecific competition, consuming resources or by reducing the numbers of native predators due to its high toxicity (Smith, 2005). We are also observing extremely rapid adaptive behavior from other animals such as birds. In the case of several snake species, they have changed morphologically in order to increase their fitness (Phillips and Shine, 2006). Australia has been impacted the most by the invasion of the cane toad, which was introduced to Queensland in 1935, as away to eliminate agricultural pests (Phillips et al, 2006). Since then it has expanded to over one million squared kilometers. There is no single approach to combat this invader, but studies have shown ways to reduce the rate of dispersal. Once such study shows that by setting barriers or adding vegetation the cane toad is unable to move to new areas (Brown et al, 2006). Further studies are needed to find the safest yet most effective way to prevent further invasion and eliminate current popolulations.

  3. The Cane Toad • Scientific name: Bufo marinus • Also known as Bufo toad or Giant toad • Native to Central and South America • Introduced to approximately 40 countries • However, introduction to the U.S. was accidental

  4. Toads Worldwide

  5. The Cane Toad • Can weight up to 5.8 lbs • Adults can reach length of up to 15 inches • Females breed once a year, laying up to 30 thousand eggs • Eggs and tadpoles are toxic • Juvenile and adults have toxic skin • Toxins originate from the parotid glands, located posterior to the eyes • Amount of toxicity typically varies with size

  6. The Cane Toad • The surface of the skin is dry and warty • They can vary in coloration from grey, brown, red and olive • Most active at night

  7. Cane Beetle • The Cane Toad was introduced to control sugar cane pests, such as the cane beetle

  8. Toxicity • Bufotenin is a chemical excreted by the Cane Toad • Can cause mild hallucinations • Lasts for less than an hour • Classified as a Class 1 drug in Australia • The practice of toad licking can lead to illness or death

  9. Toad Licking • Please DO NOT try this at home!

  10. Impact on the Ecosystem • Devastate the natural ecosystem • Voracious appetites • Can consume up to 200 invertebrates in a single meal • It can also devour small mammals • Remove more prey items form the ecosystem than native frog species • Compete with native species

  11. Mice • http://www.youtube.com/watch?v=HLacGTte-tY

  12. Impact on the Ecosystem • Kill native species • Toxins present on skin kill native predators • Toxic tadpoles kill aquatic predators

  13. Invasion • They were introduced to Queensland, Australia in 1935 • Now they cover over 1 million square kilometers

  14. Australia

  15. Effects on Native Species • Some animals have adapted to the presence of the Cane Toad • Australian snakes • Morphological Change • Birds • Hunting strategies

  16. Beware! • Toxins produced by Cane Toads can be fatal to pets

  17. Solutions • There is no ONE specific method of controlling the Cane Toad invasion • Studies have shown that Cane Toads prefer open space • Therefore, adding barriers can effectively slow down distribution • Some people kill toads on site or…..

  18. Make them into wallets and key chains

  19. The End

  20. Bibliography • Brown G.P., Phillips B.L., Webb J.K, Shine R. (2006) Toad on the road: Use of roads as dispersal corridors by cane toads (Bufo marinus) at an invasion front in tropical Australia. Biological Conservation 1 3 3: 8 8 –9 4. • Greenlees M.J., Brown G.P., Webb J.K., Phillips B.L., Shine R. (2007) Do invasive cane toads (Chaunus marinus) compete with Australian frogs (Cyclorana australis)? Austral Ecology32: 900–907. • Phillips B.L., Brown G.P., Webb J.K., Shine R. (2006) Invasion and the evolution of speed in toads. Nature 439: 803. • Phillips B.L., Shine R. (2006) Adapting to an invasive species: Toxic can toads induce morphological change in Australian snakes. PNAS 101: 17150-17155. • Phillips B.L., Shine R. (2006) Spatial and temporal variation in the morphology (and thus, predicted impact) of an invasive species in Australia. Ecography 29: 205-212. • Smith K.G. (2005) Effects of nonindigenous tadpoles on native tadpoles in Florida: evidence of competition. Biological Conservation 123: 433-441.

More Related