There
is a dark cloud hanging over the survival of the Tasmanian
Devil. This unique animal is facing the ultimate fate of
a species EXTINCTION by the way of a disease. The Devil
Facial Tumour Disease (DFTD) is an aggressive cancerous
tumour which is predominately found on the face which grows
rapidy killing the devil within only 3 to 5 months. It is
a terrible death through organ failure or starvation.
Tumours
in Tasmanian Devils is not a new occurance. Facial and Body
tumours have been detected for many years in the species,
however they were mainly internal and were not transmittable.
NOW THEY ARE!
Somewhere
along the line the tumours evolved and became contagious.
The disease spread from one devil to another creating an
epidemic that is rapidly sweeping through Tasmania at an
alarming rate stumping scientist. The Devil Facial Tumour
Disease is one of only three cancers in the world that is
contagious.
The disease was first detected in 1996 at Mount William
National Park in the far north east region of the state
and recorded by Dutch Wildlife photographer Christo Bars
who was taking photos in the area. The photo was shown to
wildlife officer Nick Mooney who recognised that this was
a tumour he had not seen before even though cancerous tumours
were not uncommon in Devils. No affected animals were detected
among the 2000-plus devils trapped by six biologists between
1964 and 1995, this was a new disease.
The disease was announced to the public in 2003. Stating
that the Tasmanian Devil was in crises and could face extinction.
The
Department of Primary Industries and Water are working closely
with research institutes across Australia including the
University of Tasmania, University of Sydney, University
of Queensland, Murdoch University in Western Australia and
Wildlife parks and zoos, to find an answer to what these
tumours are. They formed the Devil
Disease Program to investigate and identify management
problems. The main focuses being:
Population
Monitoring - Gathering data in the field to clarify
disease distribution and impacts, and to help determine
conservation strategies.
Disease
Diagnostics - A laboratory-based investigation
of the disease, including the definition, transmission,
possible causes, and so on. (For latest published research
go to www.tassiedevil.com.au)
Wild
Management - Establishing methods for managing
the impact of the disease in the wild. This includes continuing
attempts on the Forestier Tasman Peninsula, in Southern
Tasmania, to create a disease-free region.
Captive
Management - A captive breeding population with
'founders' taken from areas of the where there hasn't been
any record of the disease.
Transmission
trials are underway examining the transmission of the disease.
Preliminary results support the growing scientific acceptance
that the infective agent is a rogue cell-line passed between
devils by allograft. In other words the Devil can pass on
the disease through fighting and biting where cell tissue
is transfered from one devil to another.
Scientists
are working to determine what the disease is before they
can work out what is causing it. That may sound a little
weird, however if you think about it, it is rather logical
and makes perfect sense.
Scientist
are currently concentrating on the Tasmanian Devils inability
to fight the cancer. Looking closely at their immune system.
It seems that the Devils immune system is in perfect working
order however it is not recognising the cancer cells as
foreign and is not producing antibodies to fight them.
Latest
finding in December 2007, suggests that Devils may
lack genetic diversity. The Devils may be closely related
and share very similar genes and DNA due to low populations
and inbreeding in the past, which would explain why their
immune system is not recognising cells from another Devil
transfered by biting as foreign, it would recognise it as
being the same. If this is the case, scientist now have
to find a way to make the cancer cells visible to their
immune system so they will fight it. It is hoped that Devils
in the West and North West of the State may have a different
DNA makeup.
Nearly
all Devils who have succumbed to the disease are usually
sexually mature between the ages of two and three years
of age. This poses more concern as adult devils are only
able to breed once in their life time instead of the usual
three, the disease is killing the devils faster than they
can repopulate. The
population is getting smaller it is also getting younger
with the older devils who are more dominant and combative
resulting in the transfer of cells and contraction of the
disease. The males are usually first to be affected followed
by the females, however they are affected equally.
The
devils could be adapting with evidence that Devils could
possibly be breeding earlier and more often through the
year. Young Devils who are weaned from Diseased devils show
no sign of the disease at birth and even after 10 years
the Devils are not showing any signs of developing any natural
immunity to the disease which is not promising.
As
at December 2007, 10 years after the first sighting, the
Tasmanian Devil disease had spread to 60 separate sites
covering 59% of the State. An estimated 64% of Devils are
affected with approximately 40% of Devils have died from
the disease. At this stage the disease has only affected
the the Eastern side of the state. The west and North West
of the state is so far unaffected.
The
Boomajaril Private Property which is located in the North
West of the State is also free of the disease. Reports of
the disease is drawing closer with diseased devils being
found at Mole Creek and Cradle Mountain. We fear that it
won't be long before the disease reaches our doorstep which
will be devastating.
It is believed that there may be a natural buffer separating
devil populations from the east and the west. With mountain
ranges and wide rivers possibly keeping Devils isolated
to one side or the other. While this will not stop the disease
progressing to the west of the state, it may slow down the
spread of the infection and give them a fighting chance.