Many readers of this blog may have enjoyed the BBC's Miracle Babies presented by Martin Hughes-Games. He was filmed visiting captive breeding programmes of some of the world's most endangered species. One was a visit to Tasmanian to find out more about the Tasmanian Devil. Numbers of this marsupial have declined for the usual reasons - habitat loss, hunting and predation by the introduced red fox. In 1996 a new threat emerged - devil facial tumour disease, a highly contagious cancer that causes growths around the mouth that interfere with feeding. In 2004 a trial cull was started. Martin visited the trial site where devils are trapped and examined for presence of tumours, and any found with the disease are culled. The theory was that the removal of the diseased individuals would reduce the risk to the others. It was tough for Martin as they found an infected female with young in her pouch. The disease was so advanced that they could not keep her alive long enough for her babies to grow large enough to be fostered, so she was put down.
New research reported in the Journal of Applied Ecology has found that that the cull is not stopping the spread of the disease. Although animals were being trapped, a computer model designed to assess the cull found that approximately one-fifth of the population would never be trapped so there was a potential reservoir of diseased animals remaining in the population. The cull has now been stopped and research is looking for other ways of saving the devils. This includes the establishment of captive breeding groups and the introduction of healthy individuals into new areas. However, the best hope for the wild devils is a vaccine.
Cancer, contagious? That's not the popular conception. Really?
ReplyDelete