Tuesday, April 10, 2007

Taz Devils in Trouble
Hope the cure isn't worse than the disease

Tasmanian devils are succumbing to a contagious cancer. In some areas up to 90% of the population has died. One group has decided something needs to be done to try and save the devils from extinction, but moving a small groups to island sanctuaries where there are several endangered species may not be the best plan.

Controversial plan to save Tasmanian devils
[Hamish] McCallum is among a group of experts who plan to transfer 30 devils off Tasmania's east coast to Maria Island — a former 19th-century prison that is now home to several endangered species of birds.

The move, which state and federal governments are expected to approve within weeks, is controversial because scientists can only guess at the impact the introduced carnivores will have on the uninhabited island's ecology.

One of the difficulties in playing with ecosystems in this way is the unexpected results. For example, rabbits were introduced to Australia as a potential food source and they created vast desert-like regions by eating all the grass. Poisonous cane toads are another introduced species that has run amuck. Here in the states, English sparrows and starlings were introduced in New York’s Central Park now there are tens of millions across the country. Then there’s kudzu and zebra mussels. While I don’t think the devils would multiply in this manner, they could push some of the endangered species on the islands over the edge.
Maria would be the first of about a half-dozen islands to become quarantined colonies of wild devils, which are currently not found on any of the thousands of Tasmanian islands.

Advocates hope that if devils are wiped out on the Tasmanian mainland the disease will die along with them, and the animals placed in havens can then be safely reintroduced.

Part of natural selection is, unfortunately, the loss of individuals and even species that cannot survive threats to themselves or their population. What is happening to the devils can be compared to a plague. If some survive the disease, the species will be stronger. Such selection takes time and carries the risk that all will die either of illness or because the population becomes too dispersed for breeding. But man is impatient and doesn’t like to see nature run its course and, therefore, needs to interfere.

Moves like this have been tried before.
Maria Island has been identified previously as a potential species-saving haven.
In the 1970s, authorities said it would be an ideal sanctuary for the devils' cousin, the Tasmanian tiger — a striped, Labrador-like carnivore that like the devil carried its young in a pouch — and stocked it with kangaroos and wallabies that could be prey for the animals.

But the last known tiger died in a zoo in 1933, and long-held hopes of finding some in the wild never materialized.

Kangaroo numbers on Maria have since exploded, and hundreds have to be shot at regular intervals to prevent them starving through overgrazing.

It looks like this move is a done deal. Let’s hope that the devils survive both the disease and the introduction to their new homes, thrive in their wild sanctuaries, and come back strong.

h/t: Drew Curtis’ Fark.com

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