November 19, 2016 Biodiversity No Comments
Why are Tasmanian devils endangered

The Tasmanian devil is one of the world’s

most iconic species, but is threatened by a number of different diseases and human processes which make its continued existence unclear. The species was declared endangered in 2008 following the outbreak of the Devil Facial Tumour Disease (DFTD), which has spread through the species in the past 8 years¹.
 

    • Devil Facial Tumour Disease

The DFTD is a parasitic cancer which was first described in 1996. It is extremely aggressive, and is transmitted between devils through fighting and other means. Some high-density populations which were affected suffered a mortality rate of close to 100%. Tasmanian devil numbers have dropped by over 70% since the outbreak, and around 80 % of the remaining population is infected².

The disease is usually transmitted when one devil bites another which is infected, directly receiving the infection. Other transmission methods include consumption of an infected carcass or sharing food.

The disease usually begins as lumps or sores around the lips and mouth of the devil, and spreads rapidly. Cancerous tumours develop around the face which often spread over the entire body. Once a devil has been infected with the disease, it usually dies within six months due to organ failure, secondary infection, or starvation caused by the inability to feed².

There have been some developments in treating and preventing the disease, which does give hope to remaining devils. Some devils have been found which appear to have resistance to the disease, leading to hopes that they can recover and that a new population can be developed. Disease free populations have been isolated on both Maria Island and in a facility near Hobart. Captive breeding programs are in progress throughout both Tasmania and mainland Australia, which are designed to preserve the genetic variability of the species².

Unfortunately, this isn’t the only thing which threatens the continued existence of the Tasmanian devil. There are a number of other threats which also affect population numbers, or which have in the past, including:
 

    • Introduced Predators

Larger predators including dogs, cats, and foxes are a large threat to the devil. They compete for food and territory, which can cause starvation – especially among devils which are already hampered by facial tumours. It is thought that foxes also eat devil young, which may make it difficult for new, disease resistant populations to develop.
 

    • Habitat Loss and Fragmentation

Unfortunately, Tasmanian devils aren’t any more immune to this than any other species. Habitat fragmentation prevents the species from breeding effectively, and therefore may reduce repopulation rates. Habitat loss is relatively self-explanatory: the less area they have to live in, the lower their population can be. However, habitat fragmentation could potentially be helpful in the preservation of devil numbers, due to the fact that it may reduce the spread of the facial tumour disease – hopefully!
 

    • Roadkill

Due to the relatively high numbers of cars in Tasmania, roadkill accounts for a significant number of devil deaths every year. Ordinarily this wouldn’t be a huge problem, but with the species already strained by the DFTD, it could be the tipping point which sends them over the brink of extinction.

Tasmanian devils are the animal which everyone knows from popular media. However, they are likely to go extinct by 2035 if a cure for the DFTD is not found². If you would like to help out with devil conservation (especially if you are Australian or living in Australia!), then head over to this webpage.

 


References

¹ http://news.nationalgeographic.com/news/2008/05/080521-endangered-devils.html
² http://news.nationalgeographic.com/news/2008/05/080521-endangered-devils.html
³ http://www.tassiedevil.com.au/tasdevil.nsf/Other-threats/B5AB4796B8CE3875CA2576CB00112B91
http://www.tassiedevil.com.au/tasdevil.nsf/Other-threats/B5AB4796B8CE3875CA2576CB00112B91
http://www.tassiedevil.com.au/tasdevil.nsf/TheProgram/FBA9DE16BB72AF5CCA2576F10016CA40

Written by Greentumble Editorial Team