When I last wrote about Tasmanian devils (Sarcophilus harrisii) this past December, the species was in pretty dire straits. A contagious cancer known as Devil Facial Tumor Disease (DFTD) had, at that point, wiped out at least 70 percent of devils in the wild, forcing scientists to resort to captive breeding, a sperm bank and other reproductive research to help save the devils from extinction.
Things haven’t gotten any better: The death toll for infected Tasmanian devils has now risen to 85 percent. In an article for the Australian Broadcasting Corp. this week, researchers Kathy Belov of the University of Sydney and Carolyn Hogg of the Zoo and Aquarium Association of Australia wrote, “The disease has spread so rapidly and disastrously in the wild that we’re less confident now than we were a year ago that devils will survive this epidemic.”
While scientists attempt to develop a vaccine for DFTD, a process that could take years, Belov and Hogg say the only hope for Tasmanian devils lies in placing disease-free animals in zoos and fauna parks where they can breed in safety. (DFTD is transmitted when infected animals bite one another during mating.)
Meanwhile, other scientists are wondering what the extinction of the devil could do to the Tasmanian ecosystem. Invasive species such as foxes, black rats and European wasps could see a population boom, while grazing animals that would normally serve as prey for devils could end up threatening the island’s plant diversity, according to speakers at a Royal Society of Tasmania lecture earlier this month.
A few recent reports play up the recent births of three Tasmanian devil joeys at Taronga Zoo in Sydney as a sign of hope for the species. A species confined to life in zoos doesn’t have much in the way of hope, but for now, that will have to do.
For more on DFTD, see the Scientific American feature “The Tasmanian Devil’s Cancer: Could Contagious Tumors Affect Humans?”
Vultures continue their decline
The near-extinction of vultures in India, Nepal, Pakistan and other Asian countries continues to have terrible ecological side effects. Vultures used to serve an important role by consuming dead cattle and other carrion, but up to 99.9 percent of the birds have been wiped out by a reaction to the veterinary cattle drug diclofenac. The void created by their disappearance has been filled by stray dogs, which are eating the food the vultures used to consume and breeding out of control. Earlier this month, The New York Times reported that tens of millions of stray dogs roam India, biting millions of people every year. The bites would be bad enough, but many of the dogs also carry rabies, killing an estimated 20,000 people annually.
India banned the diclofenac in 2006, but many livestock owners did not get the message—or purposefully ignored it—and continued using the drug. Meanwhile, it seems that one of the drugs that replaced diclofenac may be just as bad: The painkiller aceclofenac metabolizes into diclofenac in cattle, according to a paper published this month in the Journal of Raptor Research. Author Pradeep Sharma from Rajasthan University of Veterinary and Animal Science told The Times of India there is a need for “comprehensive environmental evaluation” of all veterinary drugs to determine which might have further side effects on vultures.
The price of extinction
Two and a half years ago I wrote about the capture and sale of a Chinese bahaba (Bahaba taipingensis), a critically endangered fish whose swim bladder is believed to cure illnesses of the heart and lungs. That 135-kilogram fish sold for more than $500,000 and was probably one of the last of its species.
Flash forward to this month and another bahaba has turned up, this time in China’s Fujian Province, according to a report from Business Insider. The 80-kilogram fish sold for $473,000. That’s about a 40 percent premium per kilogram over the catch from 2010.
I wonder what the next bahaba will fetch at market—assuming another one ever turns up.
If you want to know more about the various militias threatening the Democratic Republic of the Congo and Virunga National Park (home to mountain gorillas and many other threatened species), then this map is essential reading.
Photos: Tasmanian devil by David Boon. Critically endangered Indian white-rumped vulture (Gyps bengalensis) by Umang Dutt. Both used under Creative Commons license