I am quoting the article in full, but you must go to the BBC website
to see a cute picture of a cute Tasmanian Devil.
A disease that threatens to wipe out the wild population of Tasmanian
devils has triggered an abrupt change in their breeding habits, a
study shows.
Devil facial tumour disease (DFTD) has led to the animals mating at an
unusually young age and females having just one litter, say
scientists.
The observed changes in the creatures' life cycle could affect the
chances of saving the iconic species, they added.
The findings appear in the Proceedings of the National Academy of Sciences.
A team of Australian scientists said they believed it to be the first
known case of an infectious disease leading to increased early
reproduction in a species of mammal.
The researchers, lead by Dr Menna Jones from the University of
Tasmania, analysed data from five sites where devil (Sarcophilus
harrisii) populations had been studied before and after the arrival of
the disease.
"Devils have shown their capacity to respond to this disease-induced
increased adult mortality with a 16-fold increase in the proportion of
individuals exhibiting precocious sexual maturity," they reported.
Devil dynamics
At all five sites, DFTD had significantly changed the age structure of
the devil populations.
DEVILS IN DETAIL
Tasmanian devils (Getty Images)
Weight: males 11kg; females 7kg
Jaws are more powerful than a tiger's
Opportunistic feeders, not specialised predators
Can smell food up to one kilometre away
Devils have at least 11 distinct vocal calls
Became "devils" in 1803 when sailors reported "unearthly" calls
The team noted that before the arrival of the disease, there was a
much higher proportion of adults more than three years old.
They also observed that the disease appeared to influence the number
of litters female devils produced.
Before the emergence of DFTD at one of the sites, the Freycinet
Peninsula on the east coast of the island, a typical female began
breeding aged two, and went on to produce annual litters for three
years, before dying in its fifth or sixth year.
"Females now generally have one breeding opportunity and may not
survive long enough to rear that litter. Hence they are now largely
semelparous [breed only once]."
Symptons of DFTD were first reported in 1996, and by 2007 the disease
had spread to more than half of the species' range on Tasmania.
The cause of the disease, which first appears as lumps or lesions
around the mouth, is unknown. There are no historical records
describing disfigured devils; although cancer was normal in the
creatures, it was usually internal.
There are a number of theories explaining the rapid emergence of the
disease, including pesticides, population dynamics, and a dormant
virus in the animals.
"This consistently fatal disease is an infectious cancer... with
tumour cells spread directly between devils biting," the researchers
explained.
"Evidence shows that most penetrating biting injuries occur among
adult males and females in the mating season."
Populations in areas where the disease has spread have experienced
declines of up to 89%, with the tumours primarily affecting adults
aged two or more, killing the animal within five months of
manifestation.
The team suggested that the disease may be frequency-dependent,
meaning that it did not disappear even when the number of hosts fell
to very low levels.
As a result, they added, there were concerns that the world's largest
carnivorous marsupial could become extinct in the wild within 20-25
years.
"This novel disease could have catastrophic consequences for the
Tasmanian devil," they warned
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